diff --git a/accessible/windows/msaa/RootAccessibleWrap.cpp b/accessible/windows/msaa/RootAccessibleWrap.cpp
index 6e9c54089dfd..1f1027798ee8 100644
--- a/accessible/windows/msaa/RootAccessibleWrap.cpp
+++ b/accessible/windows/msaa/RootAccessibleWrap.cpp
@@ -124,6 +124,9 @@ RootAccessibleWrap::accNavigate(
   if (!pvarEndUpAt) {
     return E_INVALIDARG;
   }
+  if (IsDefunct()) {
+    return CO_E_OBJNOTCONNECTED;
+  }
 
   Accessible* target = nullptr;
   // Get the document in the active tab.
diff --git a/browser/base/content/browser-menubar.inc b/browser/base/content/browser-menubar.inc
index 6dc75f7547fe..e818cdfafcbe 100644
--- a/browser/base/content/browser-menubar.inc
+++ b/browser/base/content/browser-menubar.inc
@@ -34,12 +34,6 @@
                           accesskey="&newPrivateWindow.accesskey;"
                           command="Tools:PrivateBrowsing"
                           key="key_privatebrowsing"/>
-#ifdef E10S_TESTING_ONLY
-                <menuitem id="menu_newNonRemoteWindow"
-                          label="&newNonRemoteWindow.label;"
-                          hidden="true"
-                          command="Tools:NonRemoteWindow"/>
-#endif
 #ifdef MAC_NON_BROWSER_WINDOW
                 <menuitem id="menu_openLocation"
                           label="&openLocationCmd.label;"
diff --git a/browser/base/content/browser-sets.inc b/browser/base/content/browser-sets.inc
index 49be3820199c..b353313cd07b 100644
--- a/browser/base/content/browser-sets.inc
+++ b/browser/base/content/browser-sets.inc
@@ -102,10 +102,6 @@
      oncommand="Cc['@mozilla.org/browser/browserglue;1'].getService(Ci.nsIBrowserGlue).sanitize(window);"/>
     <command id="Tools:PrivateBrowsing"
       oncommand="OpenBrowserWindow({private: true});"/>
-#ifdef E10S_TESTING_ONLY
-    <command id="Tools:NonRemoteWindow"
-      oncommand="OpenBrowserWindow({remote: false});"/>
-#endif
     <command id="History:UndoCloseTab" oncommand="undoCloseTab();"/>
     <command id="History:UndoCloseWindow" oncommand="undoCloseWindow();"/>
   </commandset>
diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
index 8831891dc375..12a03b01616c 100755
--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -1466,9 +1466,6 @@ var gBrowserInit = {
     IndexedDBPromptHelper.init();
     CanvasPermissionPromptHelper.init();
 
-    if (AppConstants.E10S_TESTING_ONLY)
-      gRemoteTabsUI.init();
-
     // Initialize the full zoom setting.
     // We do this before the session restore service gets initialized so we can
     // apply full zoom settings to tabs restored by the session restore service.
@@ -1982,9 +1979,6 @@ if (AppConstants.platform == "macosx") {
     // initialize the private browsing UI
     gPrivateBrowsingUI.init();
 
-    if (AppConstants.E10S_TESTING_ONLY) {
-      gRemoteTabsUI.init();
-    }
   };
 
   gBrowserInit.nonBrowserWindowShutdown = function() {
@@ -8283,27 +8277,6 @@ var gPrivateBrowsingUI = {
   }
 };
 
-var gRemoteTabsUI = {
-  init() {
-    if (window.location.href != getBrowserURL() &&
-        // Also check hidden window for the Mac no-window case
-        window.location.href != "chrome://browser/content/hiddenWindow.xul") {
-      return;
-    }
-
-    if (AppConstants.platform == "macosx" &&
-        Services.prefs.getBoolPref("layers.acceleration.disabled")) {
-      // On OS X, "Disable Hardware Acceleration" also disables OMTC and forces
-      // a fallback to Basic Layers. This is incompatible with e10s.
-      return;
-    }
-
-    let newNonRemoteWindow = document.getElementById("menu_newNonRemoteWindow");
-    let autostart = Services.appinfo.browserTabsRemoteAutostart;
-    newNonRemoteWindow.hidden = !autostart;
-  }
-};
-
 /**
  * Switch to a tab that has a given URI, and focuses its browser window.
  * If a matching tab is in this window, it will be switched to. Otherwise, other
@@ -8561,16 +8534,6 @@ var TabContextMenu = {
     if (this.contextTab.hasAttribute("customizemode"))
       document.getElementById("context_openTabInWindow").disabled = true;
 
-    if (AppConstants.E10S_TESTING_ONLY) {
-      menuItems = aPopupMenu.getElementsByAttribute("tbattr", "tabbrowser-remote");
-      for (let menuItem of menuItems) {
-        menuItem.hidden = !gMultiProcessBrowser;
-        if (menuItem.id == "context_openNonRemoteWindow") {
-          menuItem.disabled = !!parseInt(this.contextTab.getAttribute("usercontextid"));
-        }
-      }
-    }
-
     disabled = gBrowser.visibleTabs.length == 1;
     menuItems = aPopupMenu.getElementsByAttribute("tbattr", "tabbrowser-multiple-visible");
     for (let menuItem of menuItems)
diff --git a/browser/base/content/browser.xul b/browser/base/content/browser.xul
index 206575daa5c6..3058058ab390 100644
--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -96,12 +96,6 @@
                 accesskey="&moveToNewWindow.accesskey;"
                 tbattr="tabbrowser-multiple"
                 oncommand="gBrowser.replaceTabWithWindow(TabContextMenu.contextTab);"/>
-#ifdef E10S_TESTING_ONLY
-      <menuitem id="context_openNonRemoteWindow" label="Open in new non-e10s window"
-                tbattr="tabbrowser-remote"
-                hidden="true"
-                oncommand="gBrowser.openNonRemoteWindow(TabContextMenu.contextTab);"/>
-#endif
       <menuseparator id="context_sendTabToDevice_separator"/>
       <menu id="context_sendTabToDevice" label="&sendTabToDevice.label;"
             accesskey="&sendTabToDevice.accesskey;">
diff --git a/browser/base/content/tabbrowser.xml b/browser/base/content/tabbrowser.xml
index df1e479d677b..e14f5955d253 100644
--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -3954,20 +3954,6 @@
         </body>
       </method>
 
-      <!-- Opens a given tab to a non-remote window. -->
-      <method name="openNonRemoteWindow">
-        <parameter name="aTab"/>
-        <body>
-          <![CDATA[
-            if (!AppConstants.E10S_TESTING_ONLY) {
-              throw "This method is intended only for e10s testing!";
-            }
-            let url = aTab.linkedBrowser.currentURI.spec;
-            return window.openDialog("chrome://browser/content/", "_blank", "chrome,all,dialog=no,non-remote", url);
-          ]]>
-        </body>
-      </method>
-
       <method name="moveTabTo">
         <parameter name="aTab"/>
         <parameter name="aIndex"/>
@@ -5544,14 +5530,11 @@
             }
           } else {
             label = tab._fullLabel || tab.getAttribute("label");
-            if (AppConstants.E10S_TESTING_ONLY &&
+            if (AppConstants.NIGHTLY_BUILD &&
                 tab.linkedBrowser &&
-                tab.linkedBrowser.isRemoteBrowser) {
-              label += " - e10s";
-              if (tab.linkedBrowser.frameLoader &&
-                  Services.appinfo.maxWebProcessCount > 1) {
-                label += " (" + tab.linkedBrowser.frameLoader.tabParent.osPid + ")";
-              }
+                tab.linkedBrowser.isRemoteBrowser &&
+                tab.linkedBrowser.frameLoader) {
+              label += " (pid " + tab.linkedBrowser.frameLoader.tabParent.osPid + ")";
             }
             if (tab.userContextId) {
               label = this.mStringBundle.getFormattedString("tabs.containers.tooltip", [label, ContextualIdentityService.getUserContextLabel(tab.userContextId)]);
diff --git a/browser/branding/aurora/bgstub.bmp b/browser/branding/aurora/bgstub.bmp
deleted file mode 100644
index ed6c0ee4111c..000000000000
Binary files a/browser/branding/aurora/bgstub.bmp and /dev/null differ
diff --git a/browser/branding/aurora/bgstub.jpg b/browser/branding/aurora/bgstub.jpg
new file mode 100644
index 000000000000..9ec518c8bc0a
Binary files /dev/null and b/browser/branding/aurora/bgstub.jpg differ
diff --git a/browser/branding/aurora/bgstub_2x.jpg b/browser/branding/aurora/bgstub_2x.jpg
new file mode 100644
index 000000000000..5ee3d042cf15
Binary files /dev/null and b/browser/branding/aurora/bgstub_2x.jpg differ
diff --git a/browser/branding/branding-common.mozbuild b/browser/branding/branding-common.mozbuild
index 3feea01fc020..1bedc897d7a6 100644
--- a/browser/branding/branding-common.mozbuild
+++ b/browser/branding/branding-common.mozbuild
@@ -19,7 +19,8 @@ def FirefoxBranding():
             'VisualElements_70.png',
         ]
         BRANDING_FILES += [
-            'bgstub.bmp',
+            'bgstub.jpg',
+            'bgstub_2x.jpg',
             'branding.nsi',
             'document.ico',
             'firefox.ico',
diff --git a/browser/branding/nightly/bgstub.bmp b/browser/branding/nightly/bgstub.bmp
deleted file mode 100644
index bb08823aae64..000000000000
Binary files a/browser/branding/nightly/bgstub.bmp and /dev/null differ
diff --git a/browser/branding/nightly/bgstub.jpg b/browser/branding/nightly/bgstub.jpg
new file mode 100644
index 000000000000..3b78c9498c93
Binary files /dev/null and b/browser/branding/nightly/bgstub.jpg differ
diff --git a/browser/branding/nightly/bgstub_2x.jpg b/browser/branding/nightly/bgstub_2x.jpg
new file mode 100644
index 000000000000..c724d1803c26
Binary files /dev/null and b/browser/branding/nightly/bgstub_2x.jpg differ
diff --git a/browser/branding/official/bgstub.bmp b/browser/branding/official/bgstub.bmp
deleted file mode 100644
index 503a89a15d76..000000000000
Binary files a/browser/branding/official/bgstub.bmp and /dev/null differ
diff --git a/browser/branding/official/bgstub.jpg b/browser/branding/official/bgstub.jpg
new file mode 100644
index 000000000000..cd434b501bd6
Binary files /dev/null and b/browser/branding/official/bgstub.jpg differ
diff --git a/browser/branding/official/bgstub_2x.jpg b/browser/branding/official/bgstub_2x.jpg
new file mode 100644
index 000000000000..d73f0da6c30c
Binary files /dev/null and b/browser/branding/official/bgstub_2x.jpg differ
diff --git a/browser/branding/unofficial/bgstub.bmp b/browser/branding/unofficial/bgstub.bmp
deleted file mode 100644
index e5525507123b..000000000000
Binary files a/browser/branding/unofficial/bgstub.bmp and /dev/null differ
diff --git a/browser/branding/unofficial/bgstub.jpg b/browser/branding/unofficial/bgstub.jpg
new file mode 100644
index 000000000000..79e381bf3005
Binary files /dev/null and b/browser/branding/unofficial/bgstub.jpg differ
diff --git a/browser/branding/unofficial/bgstub_2x.jpg b/browser/branding/unofficial/bgstub_2x.jpg
new file mode 100644
index 000000000000..b971ce9cbda2
Binary files /dev/null and b/browser/branding/unofficial/bgstub_2x.jpg differ
diff --git a/browser/components/customizableui/CustomizableUI.jsm b/browser/components/customizableui/CustomizableUI.jsm
index de20ffe7e87c..81dd963122b9 100644
--- a/browser/components/customizableui/CustomizableUI.jsm
+++ b/browser/components/customizableui/CustomizableUI.jsm
@@ -59,7 +59,7 @@ const kSubviewEvents = [
  * The current version. We can use this to auto-add new default widgets as necessary.
  * (would be const but isn't because of testing purposes)
  */
-var kVersion = 12;
+var kVersion = 13;
 
 /**
  * Buttons removed from built-ins by version they were removed. kVersion must be
@@ -345,7 +345,6 @@ var CustomizableUIInternal = {
         "preferences-button",
         "add-ons-button",
         "sync-button",
-        "e10s-button",
       ];
 
       if (!AppConstants.MOZ_DEV_EDITION) {
@@ -452,6 +451,17 @@ var CustomizableUIInternal = {
         }
       }
     }
+
+    // Remove the old placements from the now-gone Nightly-only
+    // "New non-e10s window" button.
+    if (currentVersion < 13 && gSavedState.placements) {
+      for (let placements of Object.values(gSavedState.placements)) {
+        let buttonIndex = placements.indexOf("e10s-button");
+        if (buttonIndex != -1) {
+          placements.spice(buttonIndex, 1);
+        }
+      }
+    }
   },
 
   /**
diff --git a/browser/components/customizableui/CustomizableWidgets.jsm b/browser/components/customizableui/CustomizableWidgets.jsm
index 4ce4f7baf077..936cf374b3aa 100644
--- a/browser/components/customizableui/CustomizableWidgets.jsm
+++ b/browser/components/customizableui/CustomizableWidgets.jsm
@@ -997,21 +997,3 @@ if (Services.prefs.getBoolPref("privacy.panicButton.enabled")) {
     },
   });
 }
-
-if (AppConstants.E10S_TESTING_ONLY) {
-  if (Services.appinfo.browserTabsRemoteAutostart) {
-    CustomizableWidgets.push({
-      id: "e10s-button",
-      defaultArea: CustomizableUI.AREA_PANEL,
-      onBuild(aDocument) {
-        let node = aDocument.createElementNS(kNSXUL, "toolbarbutton");
-        node.setAttribute("label", CustomizableUI.getLocalizedProperty(this, "label"));
-        node.setAttribute("tooltiptext", CustomizableUI.getLocalizedProperty(this, "tooltiptext"));
-      },
-      onCommand(aEvent) {
-        let win = aEvent.view;
-        win.OpenBrowserWindow({remote: false});
-      },
-    });
-  }
-}
diff --git a/browser/components/customizableui/CustomizeMode.jsm b/browser/components/customizableui/CustomizeMode.jsm
index daf6167c8d7e..95980e8ff58f 100644
--- a/browser/components/customizableui/CustomizeMode.jsm
+++ b/browser/components/customizableui/CustomizeMode.jsm
@@ -587,6 +587,7 @@ CustomizeMode.prototype = {
         (aNode.id == "downloads-button" && aNode.hidden)) {
       return null;
     }
+
     let animationNode;
     if (aNode.parentNode && aNode.parentNode.id.startsWith("wrapper-")) {
       animationNode = aNode.parentNode;
@@ -594,13 +595,25 @@ CustomizeMode.prototype = {
       animationNode = aNode;
     }
     return new Promise(resolve => {
-      animationNode.classList.add("animate-out");
-      animationNode.addEventListener("animationend", function cleanupWidgetAnimationEnd(e) {
+      function cleanupCustomizationExit() {
+        resolveAnimationPromise();
+      }
+
+      function cleanupWidgetAnimationEnd(e) {
         if (e.animationName == "widget-animate-out" && e.target.id == animationNode.id) {
-          animationNode.removeEventListener("animationend", cleanupWidgetAnimationEnd);
-          resolve();
+          resolveAnimationPromise();
         }
-      });
+      }
+
+      function resolveAnimationPromise() {
+        animationNode.removeEventListener("animationend", cleanupWidgetAnimationEnd);
+        animationNode.removeEventListener("customizationending", cleanupCustomizationExit);
+        resolve();
+      }
+
+      animationNode.classList.add("animate-out");
+      animationNode.ownerGlobal.gNavToolbox.addEventListener("customizationending", cleanupCustomizationExit);
+      animationNode.addEventListener("animationend", cleanupWidgetAnimationEnd);
     });
   },
 
diff --git a/browser/components/customizableui/test/head.js b/browser/components/customizableui/test/head.js
index 5267dcf2da21..c4faea4e02c0 100644
--- a/browser/components/customizableui/test/head.js
+++ b/browser/components/customizableui/test/head.js
@@ -17,11 +17,6 @@ Services.scriptloader.loadSubScript("chrome://mochikit/content/tests/SimpleTest/
 Services.prefs.setBoolPref("browser.uiCustomization.skipSourceNodeCheck", true);
 registerCleanupFunction(() => Services.prefs.clearUserPref("browser.uiCustomization.skipSourceNodeCheck"));
 
-// Remove temporary e10s related new window options in customize ui,
-// they break a lot of tests.
-CustomizableUI.destroyWidget("e10s-button");
-CustomizableUI.removeWidgetFromArea("e10s-button");
-
 var {synthesizeDragStart, synthesizeDrop} = EventUtils;
 
 const kNSXUL = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
diff --git a/browser/components/preferences/in-content/main.js b/browser/components/preferences/in-content/main.js
index 4b5f696394f7..92f3f649056c 100644
--- a/browser/components/preferences/in-content/main.js
+++ b/browser/components/preferences/in-content/main.js
@@ -97,11 +97,6 @@ const APP_ICON_ATTR_NAME = "appHandlerIcon";
 XPCOMUtils.defineLazyModuleGetter(this, "OS",
   "resource://gre/modules/osfile.jsm");
 
-if (AppConstants.E10S_TESTING_ONLY) {
-  XPCOMUtils.defineLazyModuleGetter(this, "UpdateUtils",
-    "resource://gre/modules/UpdateUtils.jsm");
-}
-
 if (AppConstants.MOZ_DEV_EDITION) {
   XPCOMUtils.defineLazyModuleGetter(this, "fxAccounts",
     "resource://gre/modules/FxAccounts.jsm");
@@ -319,26 +314,6 @@ var gMainPane = {
       }
     }
 
-    if (AppConstants.E10S_TESTING_ONLY) {
-      setEventListener("e10sAutoStart", "command",
-        gMainPane.enableE10SChange);
-      let e10sCheckbox = document.getElementById("e10sAutoStart");
-
-      let e10sPref = document.getElementById("browser.tabs.remote.autostart");
-      let e10sTempPref = document.getElementById("e10sTempPref");
-      let e10sForceEnable = document.getElementById("e10sForceEnable");
-
-      let preffedOn = e10sPref.value || e10sTempPref.value || e10sForceEnable.value;
-
-      if (preffedOn) {
-        // The checkbox is checked if e10s is preffed on and enabled.
-        e10sCheckbox.checked = Services.appinfo.browserTabsRemoteAutostart;
-
-        // but if it's force disabled, then the checkbox is disabled.
-        e10sCheckbox.disabled = !Services.appinfo.browserTabsRemoteAutostart;
-      }
-    }
-
     if (AppConstants.MOZ_DEV_EDITION) {
       let uAppData = OS.Constants.Path.userApplicationDataDir;
       let ignoreSeparateProfile = OS.Path.join(uAppData, "ignore-dev-edition-profile");
@@ -546,54 +521,6 @@ var gMainPane = {
     this.readBrowserContainersCheckbox();
   },
 
-  isE10SEnabled() {
-    let e10sEnabled;
-    try {
-      let e10sStatus = Components.classes["@mozilla.org/supports-PRUint64;1"]
-        .createInstance(Ci.nsISupportsPRUint64);
-      let appinfo = Services.appinfo.QueryInterface(Ci.nsIObserver);
-      appinfo.observe(e10sStatus, "getE10SBlocked", "");
-      e10sEnabled = e10sStatus.data < 2;
-    } catch (e) {
-      e10sEnabled = false;
-    }
-
-    return e10sEnabled;
-  },
-
-  enableE10SChange() {
-    if (AppConstants.E10S_TESTING_ONLY) {
-      let e10sCheckbox = document.getElementById("e10sAutoStart");
-      let e10sPref = document.getElementById("browser.tabs.remote.autostart");
-      let e10sTempPref = document.getElementById("e10sTempPref");
-
-      let prefsToChange;
-      if (e10sCheckbox.checked) {
-        // Enabling e10s autostart
-        prefsToChange = [e10sPref];
-      } else {
-        // Disabling e10s autostart
-        prefsToChange = [e10sPref];
-        if (e10sTempPref.value) {
-          prefsToChange.push(e10sTempPref);
-        }
-      }
-
-      let buttonIndex = confirmRestartPrompt(e10sCheckbox.checked, 0,
-        true, false);
-      if (buttonIndex == CONFIRM_RESTART_PROMPT_RESTART_NOW) {
-        for (let prefToChange of prefsToChange) {
-          prefToChange.value = e10sCheckbox.checked;
-        }
-
-        Services.startup.quit(Ci.nsIAppStartup.eAttemptQuit | Ci.nsIAppStartup.eRestart);
-      }
-
-      // Revert the checkbox in case we didn't quit
-      e10sCheckbox.checked = e10sPref.value || e10sTempPref.value;
-    }
-  },
-
   separateProfileModeChange() {
     if (AppConstants.MOZ_DEV_EDITION) {
       function quitApp() {
@@ -691,15 +618,24 @@ var gMainPane = {
     // Set the "Use Current Page(s)" button's text and enabled state.
     this._updateUseCurrentButton();
 
-    // This is an async task.
-    handleControllingExtension("prefs", "homepage_override")
-      .then((isControlled) => {
-        // Disable or enable the inputs based on if this is controlled by an extension.
-        document.querySelectorAll("#browserHomePage, .homepage-button")
-          .forEach((button) => {
-            button.disabled = isControlled;
-          });
-      });
+    function setInputDisabledStates(isControlled) {
+      // Disable or enable the inputs based on if this is controlled by an extension.
+      document.querySelectorAll("#browserHomePage, .homepage-button")
+        .forEach((element) => {
+          let isLocked = document.getElementById(element.getAttribute("preference")).locked;
+          element.disabled = isLocked || isControlled;
+        });
+    }
+
+    if (homePref.locked) {
+      // An extension can't control these settings if they're locked.
+      hideControllingExtension("homepage_override");
+      setInputDisabledStates(false);
+    } else {
+      // Asynchronously update the extension controlled UI.
+      handleControllingExtension("prefs", "homepage_override")
+        .then(setInputDisabledStates);
+    }
 
     // If the pref is set to about:home or about:newtab, set the value to ""
     // to show the placeholder text (about:home title) rather than
@@ -1276,7 +1212,7 @@ var gMainPane = {
   },
 
   buildContentProcessCountMenuList() {
-    if (gMainPane.isE10SEnabled()) {
+    if (Services.appinfo.browserTabsRemoteAutostart) {
       let processCountPref = document.getElementById("dom.ipc.processCount");
       let e10sRolloutProcessCountPref =
         document.getElementById("dom.ipc.processCount.web");
diff --git a/browser/components/preferences/in-content/main.xul b/browser/components/preferences/in-content/main.xul
index 92c896b458fc..64fa7366814f 100644
--- a/browser/components/preferences/in-content/main.xul
+++ b/browser/components/preferences/in-content/main.xul
@@ -17,19 +17,6 @@
 <stringbundle id="bundlePreferences" src="chrome://browser/locale/preferences.properties"/>
 
 <preferences id="mainPreferences" hidden="true" data-category="paneGeneral">
-
-#ifdef E10S_TESTING_ONLY
-    <preference id="browser.tabs.remote.autostart"
-                name="browser.tabs.remote.autostart"
-                type="bool"/>
-    <preference id="e10sTempPref"
-                name="browser.tabs.remote.autostart.2"
-                type="bool"/>
-    <preference id="e10sForceEnable"
-                name="browser.tabs.remote.force-enable"
-                type="bool"/>
-#endif
-
     <!-- Startup -->
     <preference id="browser.startup.page"
                 name="browser.startup.page"
@@ -298,11 +285,6 @@
   </vbox>
 #endif
 
-#ifdef E10S_TESTING_ONLY
-  <checkbox id="e10sAutoStart"
-            label="&e10sEnabled.label;"/>
-#endif
-
 #ifdef HAVE_SHELL_SERVICE
   <vbox id="defaultBrowserBox">
     <checkbox id="alwaysCheckDefault" preference="browser.shell.checkDefaultBrowser"
diff --git a/browser/components/preferences/in-content/tests/browser_extension_controlled.js b/browser/components/preferences/in-content/tests/browser_extension_controlled.js
index d60267648ac9..405587e34693 100644
--- a/browser/components/preferences/in-content/tests/browser_extension_controlled.js
+++ b/browser/components/preferences/in-content/tests/browser_extension_controlled.js
@@ -32,19 +32,24 @@ function installAddon(xpiName) {
   });
 }
 
-function waitForMessageChange(messageId, cb) {
+function waitForMutation(target, opts, cb) {
   return new Promise((resolve) => {
-    let target = gBrowser.contentDocument.getElementById(messageId);
     let observer = new MutationObserver(() => {
-      if (cb(target)) {
+      if (!cb || cb(target)) {
         observer.disconnect();
         resolve();
       }
     });
-    observer.observe(target, { attributes: true, attributeFilter: ["hidden"] });
+    observer.observe(target, opts);
   });
 }
 
+function waitForMessageChange(messageId, cb) {
+  return waitForMutation(
+    gBrowser.contentDocument.getElementById(messageId),
+    { attributes: true, attributeFilter: ["hidden"] }, cb);
+}
+
 function waitForMessageHidden(messageId) {
   return waitForMessageChange(messageId, target => target.hidden);
 }
@@ -90,6 +95,146 @@ add_task(async function testExtensionControlledHomepage() {
   is(doc.getElementById("browserHomePage").disabled, false, "The homepage input is enabled");
   is(controlledContent.hidden, true, "The extension controlled row is hidden");
 
+  let addon = await AddonManager.getAddonByID("@set_homepage");
+  // Enable the extension so we get the UNINSTALL event, which is needed by
+  // ExtensionPreferencesManager to clean up properly.
+  // FIXME: See https://bugzilla.mozilla.org/show_bug.cgi?id=1408226.
+  addon.userDisabled = false;
+  await waitForMessageShown("browserHomePageExtensionContent");
+  // Do the uninstall now that the enable code has been run.
+  addon.uninstall();
+
+  await BrowserTestUtils.removeTab(gBrowser.selectedTab);
+});
+
+add_task(async function testPrefLockedHomepage() {
+  await openPreferencesViaOpenPreferencesAPI("paneGeneral", {leaveOpen: true});
+  let doc = gBrowser.contentDocument;
+  is(gBrowser.currentURI.spec, "about:preferences#general",
+     "#general should be in the URI for about:preferences");
+
+  let homePagePref = "browser.startup.homepage";
+  let buttonPrefs = [
+    "pref.browser.homepage.disable_button.current_page",
+    "pref.browser.homepage.disable_button.bookmark_page",
+    "pref.browser.homepage.disable_button.restore_default",
+  ];
+  let homePageInput = doc.getElementById("browserHomePage");
+  let prefs = Services.prefs.getDefaultBranch(null);
+  let mutationOpts = {attributes: true, attributeFilter: ["disabled"]};
+  let controlledContent = doc.getElementById("browserHomePageExtensionContent");
+
+  // Helper functions.
+  let getButton = pref => doc.querySelector(`.homepage-button[preference="${pref}"`);
+  let waitForAllMutations = () => Promise.all(
+    buttonPrefs.map(pref => waitForMutation(getButton(pref), mutationOpts))
+    .concat([waitForMutation(homePageInput, mutationOpts)]));
+  let getHomepage = () => Services.prefs.getCharPref("browser.startup.homepage");
+
+  let originalHomepage = getHomepage();
+  let extensionHomepage = "https://developer.mozilla.org/";
+  let lockedHomepage = "http://www.yahoo.com";
+
+  let lockPrefs = () => {
+    buttonPrefs.forEach(pref => {
+      prefs.setBoolPref(pref, true);
+      prefs.lockPref(pref);
+    });
+    // Do the homepage last since that's the only pref that triggers a UI update.
+    prefs.setCharPref(homePagePref, lockedHomepage);
+    prefs.lockPref(homePagePref);
+  };
+  let unlockPrefs = () => {
+    buttonPrefs.forEach(pref => {
+      prefs.unlockPref(pref);
+      prefs.setBoolPref(pref, false);
+    });
+    // Do the homepage last since that's the only pref that triggers a UI update.
+    prefs.unlockPref(homePagePref);
+    prefs.setCharPref(homePagePref, originalHomepage);
+  };
+
+  ok(originalHomepage != extensionHomepage, "The extension will change the homepage");
+
+  // Install an extension that sets the homepage to MDN.
+  await installAddon("set_homepage.xpi");
+  await waitForMessageShown(controlledContent.id);
+
+  // Check that everything is still disabled, homepage didn't change.
+  is(getHomepage(), extensionHomepage, "The reported homepage is set by the extension");
+  is(homePageInput.value, extensionHomepage, "The homepage is set by the extension");
+  is(homePageInput.disabled, true, "Homepage is disabled when set by extension");
+  buttonPrefs.forEach(pref => {
+    is(getButton(pref).disabled, true, `${pref} is disabled when set by extension`);
+  });
+  is(controlledContent.hidden, false, "The extension controlled message is shown");
+
+  // Lock all of the prefs, wait for the UI to update.
+  let messageHidden = waitForMessageHidden(controlledContent.id);
+  lockPrefs();
+  await messageHidden;
+
+  // Check that everything is now disabled.
+  is(getHomepage(), lockedHomepage, "The reported homepage is set by the pref");
+  is(homePageInput.value, lockedHomepage, "The homepage is set by the pref");
+  is(homePageInput.disabled, true, "The homepage is disabed when the pref is locked");
+  buttonPrefs.forEach(pref => {
+    is(getButton(pref).disabled, true, `The ${pref} button is disabled when locked`);
+  });
+  is(controlledContent.hidden, true, "The extension controlled message is hidden when locked");
+
+  // Unlock the prefs, wait for the UI to update.
+  let messageShown = waitForMessageShown(controlledContent.id);
+  unlockPrefs();
+  await messageShown;
+
+  // Verify that the UI is showing the extension's settings.
+  is(homePageInput.value, extensionHomepage, "The homepage is set by the extension");
+  is(homePageInput.disabled, true, "Homepage is disabled when set by extension");
+  buttonPrefs.forEach(pref => {
+    is(getButton(pref).disabled, true, `${pref} is disabled when set by extension`);
+  });
+  is(controlledContent.hidden, false, "The extension controlled message is shown when unlocked");
+
+  // Uninstall the add-on.
+  let addon = await AddonManager.getAddonByID("@set_homepage");
+  addon.uninstall();
+  await waitForMessageHidden(controlledContent.id);
+
+  // Check that everything is now enabled again.
+  is(getHomepage(), originalHomepage, "The reported homepage is reset to original value");
+  is(homePageInput.value, "", "The homepage is empty");
+  is(homePageInput.disabled, false, "The homepage is enabled after clearing lock");
+  buttonPrefs.forEach(pref => {
+    is(getButton(pref).disabled, false, `The ${pref} button is enabled when unlocked`);
+  });
+
+  // Lock the prefs without an extension.
+  lockPrefs();
+  await waitForAllMutations();
+
+  // Check that everything is now disabled.
+  is(getHomepage(), lockedHomepage, "The reported homepage is set by the pref");
+  is(homePageInput.value, lockedHomepage, "The homepage is set by the pref");
+  is(homePageInput.disabled, true, "The homepage is disabed when the pref is locked");
+  buttonPrefs.forEach(pref => {
+    is(getButton(pref).disabled, true, `The ${pref} button is disabled when locked`);
+  });
+
+  // Unlock the prefs without an extension.
+  unlockPrefs();
+  await waitForAllMutations();
+
+  // Check that everything is enabled again.
+  is(getHomepage(), originalHomepage, "The homepage is reset to the original value");
+  is(homePageInput.value, "", "The homepage is clear after being unlocked");
+  is(homePageInput.disabled, false, "The homepage is enabled after clearing lock");
+  buttonPrefs.forEach(pref => {
+    is(getButton(pref).disabled, false, `The ${pref} button is enabled when unlocked`);
+  });
+  is(controlledContent.hidden, true,
+     "The extension controlled message is hidden when unlocked with no extension");
+
   await BrowserTestUtils.removeTab(gBrowser.selectedTab);
 });
 
diff --git a/browser/extensions/formautofill/FormAutofillHeuristics.jsm b/browser/extensions/formautofill/FormAutofillHeuristics.jsm
index 59e75f18935a..969dca5390c0 100644
--- a/browser/extensions/formautofill/FormAutofillHeuristics.jsm
+++ b/browser/extensions/formautofill/FormAutofillHeuristics.jsm
@@ -62,7 +62,7 @@ class FieldScanner {
    *        The latest index of elements waiting for parsing.
    */
   set parsingIndex(index) {
-    if (index > this.fieldDetails.length) {
+    if (index > this._elements.length) {
       throw new Error("The parsing index is out of range.");
     }
     this._parsingIndex = index;
@@ -288,6 +288,70 @@ this.LabelUtils = {
 this.FormAutofillHeuristics = {
   RULES: null,
 
+  /**
+   * Try to find a contiguous sub-array within an array.
+   *
+   * @param {Array} array
+   * @param {Array} subArray
+   *
+   * @returns {boolean}
+   *          Return whether subArray was found within the array or not.
+   */
+  _matchContiguousSubArray(array, subArray) {
+    return array.some((elm, i) => subArray.every((sElem, j) => sElem == array[i + j]));
+  },
+
+  /**
+   * Try to find the field that is look like a month select.
+   *
+   * @param {DOMElement} element
+   * @returns {boolean}
+   *          Return true if we observe the trait of month select in
+   *          the current element.
+   */
+  _isExpirationMonthLikely(element) {
+    if (!(element instanceof Ci.nsIDOMHTMLSelectElement)) {
+      return false;
+    }
+
+    const options = [...element.options];
+    const desiredValues = Array(12).fill(1).map((v, i) => v + i);
+
+    // The number of month options shouldn't be less than 12 or larger than 13
+    // including the default option.
+    if (options.length < 12 || options.length > 13) {
+      return false;
+    }
+
+    return this._matchContiguousSubArray(options.map(e => +e.value), desiredValues) ||
+           this._matchContiguousSubArray(options.map(e => +e.label), desiredValues);
+  },
+
+
+  /**
+   * Try to find the field that is look like a year select.
+   *
+   * @param {DOMElement} element
+   * @returns {boolean}
+   *          Return true if we observe the trait of year select in
+   *          the current element.
+   */
+  _isExpirationYearLikely(element) {
+    if (!(element instanceof Ci.nsIDOMHTMLSelectElement)) {
+      return false;
+    }
+
+    const options = [...element.options];
+    // A normal expiration year select should contain at least the last three years
+    // in the list.
+    const curYear = new Date().getFullYear();
+    const desiredValues = Array(3).fill(0).map((v, i) => v + curYear + i);
+
+    return this._matchContiguousSubArray(options.map(e => +e.value), desiredValues) ||
+           this._matchContiguousSubArray(options.map(e => +e.label), desiredValues);
+  },
+
+
   /**
    * Try to match the telephone related fields to the grammar
    * list to see if there is any valid telephone set and correct their
@@ -392,6 +456,72 @@ this.FormAutofillHeuristics = {
     return parsedFields;
   },
 
+  /**
+   * Try to look for expiration date fields and revise the field names if needed.
+   *
+   * @param {FieldScanner} fieldScanner
+   *        The current parsing status for all elements
+   * @returns {boolean}
+   *          Return true if there is any field can be recognized in the parser,
+   *          otherwise false.
+   */
+  _parseCreditCardExpirationDateFields(fieldScanner) {
+    if (fieldScanner.parsingFinished) {
+      return false;
+    }
+
+    const savedIndex = fieldScanner.parsingIndex;
+    const monthAndYearFieldNames = ["cc-exp-month", "cc-exp-year"];
+    const detail = fieldScanner.getFieldDetailByIndex(fieldScanner.parsingIndex);
+    const element = detail.elementWeakRef.get();
+
+    // Skip the uninteresting fields
+    if (!detail || !["cc-exp", ...monthAndYearFieldNames].includes(detail.fieldName)) {
+      return false;
+    }
+
+    // If the input type is a month picker, then assume it's cc-exp.
+    if (element.type == "month") {
+      fieldScanner.updateFieldName(fieldScanner.parsingIndex, "cc-exp");
+      fieldScanner.parsingIndex++;
+
+      return true;
+    }
+
+    // Don't process the fields if expiration month and expiration year are already
+    // matched by regex in correct order.
+    if (fieldScanner.getFieldDetailByIndex(fieldScanner.parsingIndex++).fieldName == "cc-exp-month" &&
+        !fieldScanner.parsingFinished &&
+        fieldScanner.getFieldDetailByIndex(fieldScanner.parsingIndex++).fieldName == "cc-exp-year") {
+      return true;
+    }
+    fieldScanner.parsingIndex = savedIndex;
+
+    // Determine the field name by checking if the fields are month select and year select
+    // likely.
+    if (this._isExpirationMonthLikely(element)) {
+      fieldScanner.updateFieldName(fieldScanner.parsingIndex, "cc-exp-month");
+      fieldScanner.parsingIndex++;
+      const nextDetail = fieldScanner.getFieldDetailByIndex(fieldScanner.parsingIndex);
+      const nextElement = nextDetail.elementWeakRef.get();
+      if (this._isExpirationYearLikely(nextElement) && !fieldScanner.parsingFinished) {
+        fieldScanner.updateFieldName(fieldScanner.parsingIndex, "cc-exp-year");
+        fieldScanner.parsingIndex++;
+
+        return true;
+      }
+    }
+    fieldScanner.parsingIndex = savedIndex;
+
+    // If no possible regular expiration fields are detected in current parsing window
+    // fallback to "cc-exp" as there's no such case that cc-exp-month or cc-exp-year
+    // presents alone.
+    fieldScanner.updateFieldName(fieldScanner.parsingIndex, "cc-exp");
+    fieldScanner.parsingIndex++;
+
+    return true;
+  },
+
   /**
    * This function should provide all field details of a form. The details
    * contain the autocomplete info (e.g. fieldName, section, etc).
@@ -417,10 +547,11 @@ this.FormAutofillHeuristics = {
     while (!fieldScanner.parsingFinished) {
       let parsedPhoneFields = this._parsePhoneFields(fieldScanner);
       let parsedAddressFields = this._parseAddressFields(fieldScanner);
+      let parsedExpirationDateFields = this._parseCreditCardExpirationDateFields(fieldScanner);
 
       // If there is no any field parsed, the parsing cursor can be moved
       // forward to the next one.
-      if (!parsedPhoneFields && !parsedAddressFields) {
+      if (!parsedPhoneFields && !parsedAddressFields && !parsedExpirationDateFields) {
         fieldScanner.parsingIndex++;
       }
     }
diff --git a/browser/extensions/formautofill/FormAutofillUtils.jsm b/browser/extensions/formautofill/FormAutofillUtils.jsm
index 52c755c2b3a1..37f5181099f5 100644
--- a/browser/extensions/formautofill/FormAutofillUtils.jsm
+++ b/browser/extensions/formautofill/FormAutofillUtils.jsm
@@ -178,7 +178,7 @@ this.FormAutofillUtils = {
     return doc.querySelectorAll("input, select");
   },
 
-  ALLOWED_TYPES: ["text", "email", "tel", "number"],
+  ALLOWED_TYPES: ["text", "email", "tel", "number", "month"],
   isFieldEligibleForAutofill(element) {
     let tagName = element.tagName;
     if (tagName == "INPUT") {
diff --git a/browser/extensions/formautofill/test/fixtures/heuristics_cc_exp.html b/browser/extensions/formautofill/test/fixtures/heuristics_cc_exp.html
new file mode 100644
index 000000000000..785ab3650218
--- /dev/null
+++ b/browser/extensions/formautofill/test/fixtures/heuristics_cc_exp.html
@@ -0,0 +1,63 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>Heuristics cc-exp field test page</title>
+</head>
+<body>
+  <h1>Heuristics cc-exp field test page</h1>
+  <form id="form">
+    <p><label>Name: <input id="cc-name" autocomplete="cc-name"></label></p>
+    <p><label>Card Number: <input id="cc-number" autocomplete="cc-number"></label></p>
+    <p><label>Expiration month: <input id="cc-exp-month" autocomplete="cc-exp-month"></label></p>
+    <p><label>Expiration year: <input id="cc-exp-year" autocomplete="cc-exp-year"></label></p>
+    <p><label>CSC: <input id="cc-csc" autocomplete="cc-csc"></label></p>
+  </form>
+  <form id="formB">
+    <p><label>Card Number: <input id="cc-number" autocomplete="cc-number"></label></p>
+    <p><label>Expiration Date: <input autocomplete="cc-exp"></label></p>
+  </form>
+  <form id="formC">
+    <p><label>Card Number: <input id="cc-number" autocomplete="cc-number"></label></p>
+    <p><label>Expiration Date: <input type="text"></label></p>
+  </form>
+  <form id="formD">
+    <p><label>Card Number: <input id="cc-number" autocomplete="cc-number"></label></p>
+    <p>
+      <label>Exp:
+        <select>
+          <option value="1"></option>
+          <option value="2"></option>
+          <option value="3"></option>
+          <option value="4"></option>
+          <option value="5"></option>
+          <option value="6"></option>
+          <option value="7"></option>
+          <option value="8"></option>
+          <option value="9"></option>
+          <option value="10"></option>
+          <option value="11"></option>
+          <option value="12"></option>
+        </select>
+      </label>
+    </p>
+    <p>
+      <label>Exp:
+        <select>
+          <option value="2015"></option>
+          <option value="2016"></option>
+          <option value="2017"></option>
+          <option value="2018"></option>
+          <option value="2019"></option>
+          <option value="2020"></option>
+          <option value="2021"></option>
+          <option value="2022"></option>
+          <option value="2023"></option>
+          <option value="2024"></option>
+          <option value="2025"></option>
+        </select>
+      </label>
+    </p>
+  </form>
+</body>
+</html>
diff --git a/browser/extensions/formautofill/test/unit/head.js b/browser/extensions/formautofill/test/unit/head.js
index f66d8871eb49..5ce9d6b50156 100644
--- a/browser/extensions/formautofill/test/unit/head.js
+++ b/browser/extensions/formautofill/test/unit/head.js
@@ -134,6 +134,7 @@ function runHeuristicsTest(patterns, fixturePathPrefix) {
       forms.forEach((form, formIndex) => {
         let formInfo = FormAutofillHeuristics.getFormInfo(form);
         do_print("FieldName Prediction Results: " + formInfo.map(i => i.fieldName));
+        do_print("FieldName Expected Results:   " + testPattern.expectedResult[formIndex].map(i => i.fieldName));
         Assert.equal(formInfo.length, testPattern.expectedResult[formIndex].length, "Expected field count.");
         formInfo.forEach((field, fieldIndex) => {
           let expectedField = testPattern.expectedResult[formIndex][fieldIndex];
diff --git a/browser/extensions/formautofill/test/unit/heuristics/test_cc_exp.js b/browser/extensions/formautofill/test/unit/heuristics/test_cc_exp.js
new file mode 100644
index 000000000000..fa37fef23c18
--- /dev/null
+++ b/browser/extensions/formautofill/test/unit/heuristics/test_cc_exp.js
@@ -0,0 +1,32 @@
+/* global runHeuristicsTest */
+
+"use strict";
+
+runHeuristicsTest([
+  {
+    fixturePath: "heuristics_cc_exp.html",
+    expectedResult: [
+      [
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-name"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-number"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-month"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-year"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-csc"},
+      ],
+      [
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-number"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp"},
+      ],
+      [
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-number"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp"},
+      ],
+      [
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-number"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-month"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-year"},
+      ],
+    ],
+  },
+], "../../fixtures/");
+
diff --git a/browser/extensions/formautofill/test/unit/heuristics/third_party/test_CDW.js b/browser/extensions/formautofill/test/unit/heuristics/third_party/test_CDW.js
index 488bbae167aa..6e513dfb8944 100644
--- a/browser/extensions/formautofill/test/unit/heuristics/third_party/test_CDW.js
+++ b/browser/extensions/formautofill/test/unit/heuristics/third_party/test_CDW.js
@@ -44,9 +44,7 @@ runHeuristicsTest([
 //      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-type"},
         {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-number"}, // ac-off
         {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-month"},
-
-        // FIXME: bug 1392940 - the below element can not match to "cc-exp-year" regexp directly.
-//      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-year"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-year"},
 
 //      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-csc"},
       ],
diff --git a/browser/extensions/formautofill/test/unit/heuristics/third_party/test_CostCo.js b/browser/extensions/formautofill/test/unit/heuristics/third_party/test_CostCo.js
index 4f4a4c79862a..e5db650a2447 100644
--- a/browser/extensions/formautofill/test/unit/heuristics/third_party/test_CostCo.js
+++ b/browser/extensions/formautofill/test/unit/heuristics/third_party/test_CostCo.js
@@ -49,9 +49,7 @@ runHeuristicsTest([
 //      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-type"},
         {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-number"}, // ac-off
         {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-month"},
-
-        // FIXME: bug 1392940 - the below element can not match to "cc-exp-year" regexp directly.
-//      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-year"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-year"},
 
 //      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-csc"}, // ac-off
         {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-name"}, // ac-off
diff --git a/browser/extensions/formautofill/test/unit/heuristics/third_party/test_QVC.js b/browser/extensions/formautofill/test/unit/heuristics/third_party/test_QVC.js
index dee91cc40113..20a7dd570a60 100644
--- a/browser/extensions/formautofill/test/unit/heuristics/third_party/test_QVC.js
+++ b/browser/extensions/formautofill/test/unit/heuristics/third_party/test_QVC.js
@@ -17,10 +17,10 @@ runHeuristicsTest([
         // FIXME: bug 1392947 - this is a compound cc-exp field rather than the
         // separated ones below. the birthday fields are misdetected as
         // cc-exp-year and cc-exp-month.
-//      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp"},
-        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-year"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp"},
+//      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-year"},
         {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-number"},
-        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-month"},
+//      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp"},
 
 //      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-csc"},
       ],
@@ -42,10 +42,10 @@ runHeuristicsTest([
         // FIXME: bug 1392947 - this is a compound cc-exp field rather than the
         // separated ones below. the birthday fields are misdetected as
         // cc-exp-year and cc-exp-month.
-//      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp"}, // select
-        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-year"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp"}, // select
+//      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-year"},
         {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-number"}, // ac-off
-        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-month"},
+//      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp"},
 
 //      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-csc"},
       ],
diff --git a/browser/extensions/formautofill/test/unit/heuristics/third_party/test_Sears.js b/browser/extensions/formautofill/test/unit/heuristics/third_party/test_Sears.js
index b0940d3662be..d6285f142198 100644
--- a/browser/extensions/formautofill/test/unit/heuristics/third_party/test_Sears.js
+++ b/browser/extensions/formautofill/test/unit/heuristics/third_party/test_Sears.js
@@ -84,7 +84,7 @@ runHeuristicsTest([
         {"section": "", "addressType": "", "contactType": "", "fieldName": "address-level1"},
 
         // FIXME: bug 1392947 - this is for birthday actually.
-        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-year"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp"},
 //      {"section": "", "addressType": "", "contactType": "", "fieldName": "bday-month"},
 //      {"section": "", "addressType": "", "contactType": "", "fieldName": "bday-day"},
 //      {"section": "", "addressType": "", "contactType": "", "fieldName": "bday-year"},
diff --git a/browser/extensions/formautofill/test/unit/heuristics/third_party/test_Staples.js b/browser/extensions/formautofill/test/unit/heuristics/third_party/test_Staples.js
index 2e6e99914ff2..96ca788f96e4 100644
--- a/browser/extensions/formautofill/test/unit/heuristics/third_party/test_Staples.js
+++ b/browser/extensions/formautofill/test/unit/heuristics/third_party/test_Staples.js
@@ -34,11 +34,7 @@ runHeuristicsTest([
     expectedResult: [
       [
         {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-number"},
-
-        // FIXME: bug 1392940 - Since any credit card fields should be
-        // recognized no matter it's autocomplete="off" or not. This field
-        // "cc-exp-month" should be fixed as "cc-exp".
-        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-month"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp"},
 //      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-csc"},
       ],
     ],
@@ -47,11 +43,7 @@ runHeuristicsTest([
     expectedResult: [
       [
         {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-number"},
-
-        // FIXME: bug 1392940 - Since any credit card fields should be
-        // recognized no matter it's autocomplete="off" or not. This field
-        // "cc-exp-month" should be fixed as "cc-exp".
-        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp-month"},
+        {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-exp"},
 //      {"section": "", "addressType": "", "contactType": "", "fieldName": "cc-csc"},
       ],
     ],
diff --git a/browser/extensions/formautofill/test/unit/xpcshell.ini b/browser/extensions/formautofill/test/unit/xpcshell.ini
index e5cb5f23a454..3aaf1befc7ec 100644
--- a/browser/extensions/formautofill/test/unit/xpcshell.ini
+++ b/browser/extensions/formautofill/test/unit/xpcshell.ini
@@ -5,6 +5,7 @@ support-files =
   ../fixtures/**
 
 [heuristics/test_basic.js]
+[heuristics/test_cc_exp.js]
 [heuristics/third_party/test_BestBuy.js]
 [heuristics/third_party/test_CDW.js]
 [heuristics/third_party/test_CostCo.js]
diff --git a/browser/installer/windows/Makefile.in b/browser/installer/windows/Makefile.in
index 9c74e3d4bf09..15ddc31267e2 100644
--- a/browser/installer/windows/Makefile.in
+++ b/browser/installer/windows/Makefile.in
@@ -23,7 +23,8 @@ INSTALLER_FILES += \
 endif
 
 BRANDING_FILES = \
-	bgstub.bmp \
+	bgstub.jpg \
+	bgstub_2x.jpg \
 	branding.nsi \
 	firefox64.ico \
 	wizHeader.bmp \
diff --git a/browser/installer/windows/nsis/stub.nsi b/browser/installer/windows/nsis/stub.nsi
index 75446a1ed574..f42afe449dd7 100644
--- a/browser/installer/windows/nsis/stub.nsi
+++ b/browser/installer/windows/nsis/stub.nsi
@@ -469,7 +469,8 @@ Function .onInit
   CreateFont $FontCheckbox   "$0" "10" "400"
 
   InitPluginsDir
-  File /oname=$PLUGINSDIR\bgstub.bmp "bgstub.bmp"
+  File /oname=$PLUGINSDIR\bgstub.jpg "bgstub.jpg"
+  File /oname=$PLUGINSDIR\bgstub_2x.jpg "bgstub_2x.jpg"
 
   SetShellVarContext all ; Set SHCTX to All Users
   ; If the user doesn't have write access to the installation directory set
@@ -565,6 +566,26 @@ Function .onUserAbort
   Abort
 FunctionEnd
 
+Function DrawBackgroundImage
+  ${NSD_CreateBitmap} 0 0 100% 100% ""
+  Pop $HwndBgBitmapControl
+
+  ; If the scaling factor is 100%, use the 1x image; the 2x images scaled down
+  ; by that much don't always look good because some of them use thinner lines
+  ; and a darker background (over which aliasing is more visible).
+  System::Call 'user32::GetWindowDC(i $HWNDPARENT) i .r0'
+  System::Call 'gdi32::GetDeviceCaps(i $0, i 88) i .r1' ; 88 = LOGPIXELSX
+  System::Call 'user32::ReleaseDC(i $HWNDPARENT, i $0)'
+  ${If} $1 <= 96
+    ${SetStretchedImageOLE} $HwndBgBitmapControl $PLUGINSDIR\bgstub.jpg $BgBitmapImage
+  ${Else}
+    ${SetStretchedImageOLE} $HwndBgBitmapControl $PLUGINSDIR\bgstub_2x.jpg $BgBitmapImage
+  ${EndIf}
+
+  ; transparent bg on control prevents flicker on redraw
+  SetCtlColors $HwndBgBitmapControl ${INSTALL_BLURB_TEXT_COLOR} transparent
+FunctionEnd
+
 Function createProfileCleanup
   Call ShouldPromptForProfileCleanup
   ${Select} $ProfileCleanupPromptType
@@ -702,11 +723,7 @@ Function createProfileCleanup
   SendMessage $0 ${WM_SETFONT} $FontFooter 0
   SetCtlColors $0 ${INSTALL_BLURB_TEXT_COLOR} transparent
 
-  ${NSD_CreateBitmap} 0 0 100% 100% ""
-  Pop $HwndBgBitmapControl
-  ${NSD_SetStretchedImage} $HwndBgBitmapControl $PLUGINSDIR\bgstub.bmp $BgBitmapImage
-  ; transparent bg on control prevents flicker on redraw
-  SetCtlColors $HwndBgBitmapControl ${INSTALL_BLURB_TEXT_COLOR} transparent
+  Call DrawBackgroundImage
 
   LockWindow off
   nsDialogs::Show
@@ -784,11 +801,7 @@ Function createInstall
   SendMessage $Progressbar ${PBM_SETMARQUEE} 1 \
               $ProgressbarMarqueeIntervalMS ; start=1|stop=0 interval(ms)=+N
 
-  ${NSD_CreateBitmap} 0 0 100% 100% ""
-  Pop $HwndBgBitmapControl
-  ${NSD_SetStretchedImage} $HwndBgBitmapControl $PLUGINSDIR\bgstub.bmp $BgBitmapImage
-  ; transparent bg on control prevents flicker on redraw
-  SetCtlColors $HwndBgBitmapControl ${INSTALL_BLURB_TEXT_COLOR} transparent
+  Call DrawBackgroundImage
 
   GetDlgItem $0 $HWNDPARENT 1 ; Install button
   EnableWindow $0 0
diff --git a/browser/locales/en-US/chrome/browser/browser.dtd b/browser/locales/en-US/chrome/browser/browser.dtd
index dfbaeaba44cd..1103f042a06d 100644
--- a/browser/locales/en-US/chrome/browser/browser.dtd
+++ b/browser/locales/en-US/chrome/browser/browser.dtd
@@ -294,7 +294,6 @@ These should match what Safari and other Apple applications use on OS X Lion. --
 <!ENTITY newNavigatorCmd.accesskey      "N">
 <!ENTITY newPrivateWindow.label     "New Private Window">
 <!ENTITY newPrivateWindow.accesskey "W">
-<!ENTITY newNonRemoteWindow.label   "New Non-e10s Window">
 
 <!ENTITY editMenu.label         "Edit">
 <!ENTITY editMenu.accesskey       "E">
diff --git a/browser/locales/en-US/chrome/browser/customizableui/customizableWidgets.properties b/browser/locales/en-US/chrome/browser/customizableui/customizableWidgets.properties
index 84403c3ef53a..762068a1688b 100644
--- a/browser/locales/en-US/chrome/browser/customizableui/customizableWidgets.properties
+++ b/browser/locales/en-US/chrome/browser/customizableui/customizableWidgets.properties
@@ -101,9 +101,6 @@ panic-button.tooltiptext = Forget about some browsing history
 devtools-webide-button2.label = WebIDE
 devtools-webide-button2.tooltiptext = Open WebIDE (%S)
 
-e10s-button.label = New Non-e10s Window
-e10s-button.tooltiptext = Open a new Non-e10s Window
-
 toolbarspring.label = Flexible Space
 toolbarseparator.label = Separator
 toolbarspacer.label = Space
diff --git a/browser/locales/en-US/chrome/browser/preferences/main.dtd b/browser/locales/en-US/chrome/browser/preferences/main.dtd
index 924f6f2fd14e..cf5c569ed6ea 100644
--- a/browser/locales/en-US/chrome/browser/preferences/main.dtd
+++ b/browser/locales/en-US/chrome/browser/preferences/main.dtd
@@ -44,5 +44,3 @@
 <!ENTITY useFirefoxSync.label             "Tip: This uses separate profiles. Use Sync to share data between them.">
 <!ENTITY getStarted.notloggedin.label     "Sign in to &syncBrand.shortName.label;…">
 <!ENTITY getStarted.configured.label      "Open &syncBrand.shortName.label; preferences">
-
-<!ENTITY e10sEnabled.label                "Enable multi-process &brandShortName;">
diff --git a/browser/themes/shared/tabs.inc.css b/browser/themes/shared/tabs.inc.css
index a5879d1bccae..c121d681c696 100644
--- a/browser/themes/shared/tabs.inc.css
+++ b/browser/themes/shared/tabs.inc.css
@@ -509,9 +509,9 @@ tabbrowser {
 
 /* Pinned tab separators need position: absolute when positioned (during overflow). */
 #tabbrowser-tabs[positionpinnedtabs] > .tabbrowser-tab[pinned]::after {
-  height: 100%;
   position: absolute;
   top: 0;
+  bottom: 0;
   right: 0;
 }
 
@@ -558,14 +558,8 @@ tabbrowser {
 .tabbrowser-tab::after,
 .tabbrowser-tab::before {
   border-left: 1px solid;
-  /* Vertical margin doesn't work here for positioned pinned tabs, see
-     bug 1198236 and bug 1300410. We're using linear-gradient instead
-     to cut off the border at the top and at the bottom. */
-  border-image: linear-gradient(transparent 6px,
-                                currentColor 6px,
-                                currentColor calc(100% - 5px),
-                                transparent calc(100% - 5px));
-  border-image-slice: 1;
+  margin-top: 5px;
+  margin-bottom: 4px;
   opacity: 0.3;
 }
 
@@ -579,11 +573,8 @@ tabbrowser {
 /* Show full height tab separators on hover. */
 .tabbrowser-tab:hover::after,
 #tabbrowser-tabs:not([movingtab]) > .tabbrowser-tab[beforehovered]::after {
-  border-image: linear-gradient(transparent calc(1px + var(--tabs-top-border-width)),
-                                currentColor calc(1px + var(--tabs-top-border-width)),
-                                currentColor calc(100% - 1px),
-                                transparent calc(100% - 1px));
-  border-image-slice: 1;
+  margin-top: var(--tabs-top-border-width);
+  margin-bottom: 0;
 }
 
 /* Show full height tab separators on selected tabs. */
@@ -591,10 +582,8 @@ tabbrowser {
 #tabbrowser-tabs[movingtab] > .tabbrowser-tab[visuallyselected]::before,
 .tabbrowser-tab[visuallyselected]::after {
   border-color: var(--tabs-border);
-  border-image: linear-gradient(transparent 1px,
-                                var(--tabs-border) 1px,
-                                var(--tabs-border) calc(100% - 1px - var(--tab-toolbar-navbar-overlap)),
-                                transparent calc(100% - 1px - var(--tab-toolbar-navbar-overlap))) 1 !important;
+  margin-top: 0;
+  margin-bottom: var(--tab-toolbar-navbar-overlap);
   opacity: 1;
 }
 
diff --git a/browser/themes/shared/toolbarbutton-icons.inc.css b/browser/themes/shared/toolbarbutton-icons.inc.css
index 9ee2107c3397..d1e672db7f46 100644
--- a/browser/themes/shared/toolbarbutton-icons.inc.css
+++ b/browser/themes/shared/toolbarbutton-icons.inc.css
@@ -229,14 +229,6 @@ toolbar[brighttext] {
   list-style-image: url("chrome://browser/skin/new-window.svg");
 }
 
-#e10s-button {
-  list-style-image: url("chrome://browser/skin/new-window.svg");
-}
-
-#e10s-button > .toolbarbutton-icon {
-  transform: scaleY(-1);
-}
-
 #new-tab-button {
   list-style-image: url("chrome://browser/skin/new-tab.svg");
 }
diff --git a/build/unix/build-gcc/build-gcc.sh b/build/unix/build-gcc/build-gcc.sh
index e39b2461a4bb..774549f221bb 100755
--- a/build/unix/build-gcc/build-gcc.sh
+++ b/build/unix/build-gcc/build-gcc.sh
@@ -66,8 +66,26 @@ prepare() {
   popd
 }
 
+prepare_mingw() {
+  export install_dir=$root_dir/tools/gcc/
+  mkdir -p $install_dir
+  export PATH=$PATH:$install_dir/bin/
+
+  cd $root_dir
+
+  git clone -n git://git.code.sf.net/p/mingw-w64/mingw-w64
+  pushd mingw-w64
+  git checkout $mingw_version # Asserts the integrity of the checkout (Right?)
+  popd
+}
+
 apply_patch() {
-  pushd $root_dir/gcc-$gcc_version
+  if [ $# -ge 2 ]; then
+    pushd $root_dir/$1
+    shift
+  else
+    pushd $root_dir/gcc-$gcc_version
+  fi
   patch -p1 < $1
   popd
 }
@@ -102,17 +120,6 @@ build_gcc() {
 }
 
 build_gcc_and_mingw() {
-  export install_dir=$root_dir/tools/gcc/
-  mkdir -p $install_dir
-  export PATH=$PATH:$install_dir/bin/
-
-  cd $root_dir
-
-  git clone -n git://git.code.sf.net/p/mingw-w64/mingw-w64
-  pushd mingw-w64
-  git checkout $mingw_version # Asserts the integrity of the checkout (Right?)
-  popd
-
   mkdir gcc-objdir
   pushd gcc-objdir
   ../gcc-$gcc_version/configure --prefix=$install_dir --target=i686-w64-mingw32 --with-gnu-ld --with-gnu-as --disable-multilib --enable-threads=posix
diff --git a/devtools/client/animationinspector/animation-controller.js b/devtools/client/animationinspector/animation-controller.js
index 9a9239e55a66..131539a81bf1 100644
--- a/devtools/client/animationinspector/animation-controller.js
+++ b/devtools/client/animationinspector/animation-controller.js
@@ -228,12 +228,16 @@ var AnimationsController = {
   }),
 
   onNewNodeFront: Task.async(function* () {
-    // Ignore if the panel isn't visible or the node selection hasn't changed.
-    if (!this.isPanelVisible() ||
-        this.nodeFront === gInspector.selection.nodeFront) {
+    // Ignore if the panel isn't visible.
+    // Or the node selection hasn't changed and no animation mutations event occurs during
+    // hidden.
+    if (!this.isPanelVisible() || (this.nodeFront === gInspector.selection.nodeFront &&
+                                   !this.mutationsDetectedWhileHidden)) {
       return;
     }
 
+    this.mutationsDetectedWhileHidden = false;
+
     this.nodeFront = gInspector.selection.nodeFront;
     let done = gInspector.updating("animationscontroller");
 
@@ -361,8 +365,14 @@ var AnimationsController = {
       }
     }
 
-    // Let the UI know the list has been updated.
-    this.emit(this.PLAYERS_UPDATED_EVENT, this.animationPlayers);
+    if (this.isPanelVisible()) {
+      // Let the UI know the list has been updated.
+      this.emit(this.PLAYERS_UPDATED_EVENT, this.animationPlayers);
+    } else {
+      // Avoid updating the UI while the panel is hidden.
+      // This avoids unnecessary work.
+      this.mutationsDetectedWhileHidden = true;
+    }
   },
 
   /**
diff --git a/devtools/client/animationinspector/components/animation-timeline.js b/devtools/client/animationinspector/components/animation-timeline.js
index 26435ab17eeb..0d07a2734f3b 100644
--- a/devtools/client/animationinspector/components/animation-timeline.js
+++ b/devtools/client/animationinspector/components/animation-timeline.js
@@ -328,12 +328,15 @@ AnimationsTimeline.prototype = {
         continue;
       }
       if (i === index) {
-        // Already the animation is selected.
-        this.emit("animation-already-selected", this.animations[i]);
-        return;
+        if (this.animationRootEl.classList.contains("animation-detail-visible")) {
+          // Already the animation is selected.
+          this.emit("animation-already-selected", this.animations[i]);
+          return;
+        }
+      } else {
+        animationEl.classList.remove("selected");
+        this.emit("animation-unselected", this.animations[i]);
       }
-      animationEl.classList.remove("selected");
-      this.emit("animation-unselected", this.animations[i]);
       break;
     }
 
diff --git a/devtools/client/animationinspector/test/browser.ini b/devtools/client/animationinspector/test/browser.ini
index 58bf0085afc9..6783e9c5ff93 100644
--- a/devtools/client/animationinspector/test/browser.ini
+++ b/devtools/client/animationinspector/test/browser.ini
@@ -48,6 +48,7 @@ skip-if = os == "linux" && !debug # Bug 1234567
 [browser_animation_refresh_on_removed_animation.js]
 skip-if = os == "linux" && !debug # Bug 1227792
 [browser_animation_refresh_when_active.js]
+[browser_animation_refresh_when_active_after_mutations.js]
 [browser_animation_running_on_compositor.js]
 [browser_animation_same_nb_of_playerWidgets_and_playerFronts.js]
 [browser_animation_shows_player_on_valid_node.js]
diff --git a/devtools/client/animationinspector/test/browser_animation_detail_displayed.js b/devtools/client/animationinspector/test/browser_animation_detail_displayed.js
index 808dcba33c73..309b9b960e05 100644
--- a/devtools/client/animationinspector/test/browser_animation_detail_displayed.js
+++ b/devtools/client/animationinspector/test/browser_animation_detail_displayed.js
@@ -12,6 +12,7 @@
 // 4. Display from first time if displayed animation is only one.
 // 5. Close the animation-detail element by clicking on close button.
 // 6. Stay selected animation even if refresh all UI.
+// 7. Close the animation-detail element again and click selected animation again.
 
 requestLongerTimeout(5);
 
@@ -28,7 +29,7 @@ add_task(function* () {
   ok(animationDetailEl, "The animation-detail element should exist");
 
   // 2. Hidden at first if multiple animations were displayed.
-  const win = animationDetailEl.ownerDocument.defaultView;
+  const win = timelineComponent.rootWrapperEl.ownerGlobal;
   is(win.getComputedStyle(splitboxControlledEl).display, "none",
      "The animation-detail element should be hidden at first "
      + "if multiple animations were displayed");
@@ -45,10 +46,7 @@ add_task(function* () {
 
   // 5. Close the animation-detail element by clicking on close button.
   const previousHeight = animationDetailEl.offsetHeight;
-  const button = animationDetailEl.querySelector(".animation-detail-header button");
-  const onclosed = timelineComponent.once("animation-detail-closed");
-  EventUtils.sendMouseEvent({type: "click"}, button, win);
-  yield onclosed;
+  yield clickCloseButtonForDetailPanel(timelineComponent, animationDetailEl);
   is(win.getComputedStyle(splitboxControlledEl).display, "none",
      "animation-detail element should not display");
 
@@ -64,4 +62,24 @@ add_task(function* () {
   yield clickTimelineRewindButton(panel);
   ok(animationDetailEl.querySelector(".property"),
      "The property in animation-detail element should stay as is");
+
+  // 7. Close the animation-detail element again and click selected animation again.
+  yield clickCloseButtonForDetailPanel(timelineComponent, animationDetailEl);
+  yield clickOnAnimation(panel, 0);
+  isnot(win.getComputedStyle(splitboxControlledEl).display, "none",
+     "animation-detail element should display again");
 });
+
+/**
+ * Click close button for animation-detail panel.
+ *
+ * @param {AnimationTimeline} AnimationTimeline component
+ * @param {DOMNode} animation-detail element
+ * @return {Promise} which wait for close the detail pane
+ */
+function* clickCloseButtonForDetailPanel(timeline, element) {
+  const button = element.querySelector(".animation-detail-header button");
+  const onclosed = timeline.once("animation-detail-closed");
+  EventUtils.sendMouseEvent({type: "click"}, button, element.ownerDocument.defaultView);
+  return yield onclosed;
+}
diff --git a/devtools/client/animationinspector/test/browser_animation_refresh_when_active_after_mutations.js b/devtools/client/animationinspector/test/browser_animation_refresh_when_active_after_mutations.js
new file mode 100644
index 000000000000..125680fcd148
--- /dev/null
+++ b/devtools/client/animationinspector/test/browser_animation_refresh_when_active_after_mutations.js
@@ -0,0 +1,54 @@
+/* vim: set ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+requestLongerTimeout(2);
+
+// Test that refresh animation UI while the panel is hidden.
+
+const EXPECTED_GRAPH_PATH_SEGMENTS = [{ x: 0, y: 0 },
+                                      { x: 49999, y: 0.0 },
+                                      { x: 50000, y: 0.5 },
+                                      { x: 99999, y: 0.5 },
+                                      { x: 100000, y: 0 }];
+
+add_task(function* () {
+  info("Open animation inspector once so that activate animation mutations listener");
+  yield addTab("data:text/html;charset=utf8,<div id='target'>test</div>");
+  const { controller, inspector, panel } = yield openAnimationInspector();
+
+  info("Select other tool to hide animation inspector");
+  yield inspector.sidebar.select("ruleview");
+
+  // Count players-updated event in controller.
+  let updatedEventCount = 0;
+  controller.on("players-updated", () => {
+    updatedEventCount += 1;
+  });
+
+  info("Make animation by eval in content");
+  yield evalInDebuggee(gBrowser.selectedBrowser.messageManager,
+                       `document.querySelector('#target').animate(
+                        { transform: 'translate(100px)' },
+                        { duration: 100000, easing: 'steps(2)' });`);
+  info("Wait for animation mutations event");
+  yield controller.animationsFront.once("mutations");
+  info("Check players-updated events count");
+  is(updatedEventCount, 0, "players-updated event shoud not be fired");
+
+  info("Re-select animation inspector and check the UI");
+  yield inspector.sidebar.select("animationinspector");
+  yield waitForAnimationTimelineRendering(panel);
+
+  const timeBlocks = getAnimationTimeBlocks(panel);
+  is(timeBlocks.length, 1, "One animation should display");
+  const timeBlock = timeBlocks[0];
+  const state = timeBlock.animation.state;
+  const effectEl = timeBlock.containerEl.querySelector(".effect-easing");
+  ok(effectEl, "<g> element for effect easing should exist");
+  const pathEl = effectEl.querySelector("path");
+  ok(pathEl, "<path> element for effect easing should exist");
+  assertPathSegments(pathEl, state.duration, false, EXPECTED_GRAPH_PATH_SEGMENTS);
+});
diff --git a/devtools/client/debugger/new/test/mochitest/browser.ini b/devtools/client/debugger/new/test/mochitest/browser.ini
index bfeeb9daf327..653e11178688 100644
--- a/devtools/client/debugger/new/test/mochitest/browser.ini
+++ b/devtools/client/debugger/new/test/mochitest/browser.ini
@@ -67,6 +67,8 @@ support-files =
 [browser_dbg-breakpoints-reloading.js]
 skip-if = true # Bug 1383576
 [browser_dbg-breakpoints-cond.js]
+[browser_dbg-browser-content-toolbox.js]
+skip-if = !e10s # This test is only valid in e10s
 [browser_dbg-call-stack.js]
 [browser_dbg-scopes.js]
 [browser_dbg-chrome-create.js]
@@ -107,5 +109,5 @@ skip-if = true # Bug 1393121, 1393299
 [browser_dbg-tabs.js]
 [browser_dbg-toggling-tools.js]
 [browser_dbg-wasm-sourcemaps.js]
-skip-if = true 
+skip-if = true
 [browser_dbg-reload.js]
diff --git a/devtools/client/debugger/new/test/mochitest/browser_dbg-browser-content-toolbox.js b/devtools/client/debugger/new/test/mochitest/browser_dbg-browser-content-toolbox.js
new file mode 100644
index 000000000000..0afe210a205b
--- /dev/null
+++ b/devtools/client/debugger/new/test/mochitest/browser_dbg-browser-content-toolbox.js
@@ -0,0 +1,73 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * Tests that the debugger is succesfully loaded in the Browser Content Toolbox.
+ */
+
+const {gDevToolsBrowser} = require("devtools/client/framework/devtools-browser");
+
+function toggleBreakpoint(dbg, index) {
+  const bp = findElement(dbg, "breakpointItem", index);
+  const input = bp.querySelector("input");
+  input.click();
+}
+
+async function disableBreakpoint(dbg, index) {
+  const disabled = waitForDispatch(dbg, "DISABLE_BREAKPOINT");
+  toggleBreakpoint(dbg, index);
+  await disabled;
+}
+
+async function enableBreakpoint(dbg, index) {
+  const enabled = waitForDispatch(dbg, "ENABLE_BREAKPOINT");
+  toggleBreakpoint(dbg, index);
+  await enabled;
+}
+
+function findBreakpoint(dbg, url, line) {
+  const { selectors: { getBreakpoint }, getState } = dbg;
+  const source = findSource(dbg, url);
+  return getBreakpoint(getState(), { sourceId: source.id, line });
+}
+
+add_task(async function() {
+  clearDebuggerPreferences();
+
+  info("Open a tab pointing to doc-scripts.html");
+  await addTab(EXAMPLE_URL + "doc-scripts.html");
+
+  info("Open the Browser Content Toolbox");
+  let toolbox = await gDevToolsBrowser.openContentProcessToolbox(gBrowser);
+
+  info("Wait for the debugger to be ready");
+  await toolbox.getPanelWhenReady("jsdebugger");
+
+  let dbg = createDebuggerContext(toolbox);
+  ok(dbg, "Debugger context is available");
+
+  info("Create a breakpoint");
+  await selectSource(dbg, "simple2");
+  await addBreakpoint(dbg, "simple2", 3);
+
+  info("Disable the breakpoint");
+  await disableBreakpoint(dbg, 1);
+  let bp = findBreakpoint(dbg, "simple2", 3);
+  is(bp.disabled, true, "breakpoint is disabled");
+
+  info("Enable the breakpoint");
+  await enableBreakpoint(dbg, 1);
+  bp = findBreakpoint(dbg, "simple2", 3);
+  is(bp.disabled, false, "breakpoint is enabled");
+
+  info("Close the browser toolbox window");
+  let onToolboxDestroyed = toolbox.once("destroyed");
+  toolbox.win.top.close();
+  await onToolboxDestroyed;
+
+  info("Toolbox is destroyed");
+});
diff --git a/devtools/client/debugger/new/test/mochitest/head.js b/devtools/client/debugger/new/test/mochitest/head.js
index cda5800ec386..0dcbc69d47b5 100644
--- a/devtools/client/debugger/new/test/mochitest/head.js
+++ b/devtools/client/debugger/new/test/mochitest/head.js
@@ -366,23 +366,30 @@ function createDebuggerContext(toolbox) {
   };
 }
 
+
+/**
+ * Clear all the debugger related preferences.
+ */
+function clearDebuggerPreferences() {
+  Services.prefs.clearUserPref("devtools.debugger.pause-on-exceptions");
+  Services.prefs.clearUserPref("devtools.debugger.ignore-caught-exceptions");
+  Services.prefs.clearUserPref("devtools.debugger.tabs");
+  Services.prefs.clearUserPref("devtools.debugger.pending-selected-location");
+  Services.prefs.clearUserPref("devtools.debugger.pending-breakpoints");
+  Services.prefs.clearUserPref("devtools.debugger.expressions");
+}
+
 /**
  * Intilializes the debugger.
  *
  * @memberof mochitest
  * @param {String} url
- * @param {Array} sources
  * @return {Promise} dbg
  * @static
  */
-function initDebugger(url, ...sources) {
+function initDebugger(url) {
   return Task.spawn(function*() {
-    Services.prefs.clearUserPref("devtools.debugger.pause-on-exceptions");
-    Services.prefs.clearUserPref("devtools.debugger.ignore-caught-exceptions");
-    Services.prefs.clearUserPref("devtools.debugger.tabs");
-    Services.prefs.clearUserPref("devtools.debugger.pending-selected-location");
-    Services.prefs.clearUserPref("devtools.debugger.pending-breakpoints");
-    Services.prefs.clearUserPref("devtools.debugger.expressions");
+    clearDebuggerPreferences();
     const toolbox = yield openNewTabAndToolbox(EXAMPLE_URL + url, "jsdebugger");
     return createDebuggerContext(toolbox);
   });
diff --git a/devtools/client/framework/devtools-browser.js b/devtools/client/framework/devtools-browser.js
index 041dd16affee..14007e37c5dc 100644
--- a/devtools/client/framework/devtools-browser.js
+++ b/devtools/client/framework/devtools-browser.js
@@ -363,7 +363,13 @@ var gDevToolsBrowser = exports.gDevToolsBrowser = {
     return deferred.promise;
   },
 
-   // Used by menus.js
+  /**
+   * Open the Browser Content Toolbox for the provided gBrowser instance.
+   * Returns a promise that resolves with a toolbox instance. If no content process is
+   * available, the promise will be rejected and a message will be displayed to the user.
+   *
+   * Used by menus.js
+  */
   openContentProcessToolbox(gBrowser) {
     let { childCount } = Services.ppmm;
     // Get the process message manager for the current tab
@@ -377,16 +383,17 @@ var gDevToolsBrowser = exports.gDevToolsBrowser = {
       }
     }
     if (processId) {
-      this._getContentProcessTarget(processId)
+      return this._getContentProcessTarget(processId)
           .then(target => {
             // Display a new toolbox, in a new window, with debugger by default
             return gDevTools.showToolbox(target, "jsdebugger",
                                          Toolbox.HostType.WINDOW);
           });
-    } else {
-      let msg = L10N.getStr("toolbox.noContentProcessForTab.message");
-      Services.prompt.alert(null, "", msg);
     }
+
+    let msg = L10N.getStr("toolbox.noContentProcessForTab.message");
+    Services.prompt.alert(null, "", msg);
+    return Promise.reject(msg);
   },
 
   /**
diff --git a/devtools/client/framework/source-map-url-service.js b/devtools/client/framework/source-map-url-service.js
index 32a3587fd401..fe4ff87fbdbf 100644
--- a/devtools/client/framework/source-map-url-service.js
+++ b/devtools/client/framework/source-map-url-service.js
@@ -138,7 +138,8 @@ SourceMapURLService.prototype._onNewStyleSheet = function (sheet) {
     return;
   }
 
-  let {href: url, sourceMapURL, actor: id} = sheet._form;
+  let {href, nodeHref, sourceMapURL, actorID: id} = sheet;
+  let url = href || nodeHref;
   this._urls.set(url, { id, url, sourceMapURL});
   this._idMap.set(id, url);
 };
diff --git a/devtools/client/inspector/computed/computed.js b/devtools/client/inspector/computed/computed.js
index 17bdc0f9900c..ceaed6ce1051 100644
--- a/devtools/client/inspector/computed/computed.js
+++ b/devtools/client/inspector/computed/computed.js
@@ -10,7 +10,6 @@ const ToolDefinitions = require("devtools/client/definitions").Tools;
 const CssLogic = require("devtools/shared/inspector/css-logic");
 const {ELEMENT_STYLE} = require("devtools/shared/specs/styles");
 const promise = require("promise");
-const Services = require("Services");
 const OutputParser = require("devtools/client/shared/output-parser");
 const {PrefObserver} = require("devtools/client/shared/prefs");
 const {createChild} = require("devtools/client/inspector/shared/utils");
@@ -37,8 +36,6 @@ const STYLE_INSPECTOR_PROPERTIES = "devtools/shared/locales/styleinspector.prope
 const {LocalizationHelper} = require("devtools/shared/l10n");
 const STYLE_INSPECTOR_L10N = new LocalizationHelper(STYLE_INSPECTOR_PROPERTIES);
 
-const PREF_ORIG_SOURCES = "devtools.source-map.client-service.enabled";
-
 const FILTER_CHANGED_TIMEOUT = 150;
 const HTML_NS = "http://www.w3.org/1999/xhtml";
 
@@ -205,9 +202,7 @@ function CssComputedView(inspector, document, pageStyle) {
   // Refresh panel when color unit changed or pref for showing
   // original sources changes.
   this._handlePrefChange = this._handlePrefChange.bind(this);
-  this._onSourcePrefChanged = this._onSourcePrefChanged.bind(this);
   this._prefObserver = new PrefObserver("devtools.");
-  this._prefObserver.on(PREF_ORIG_SOURCES, this._onSourcePrefChanged);
   this._prefObserver.on("devtools.defaultColorUnit", this._handlePrefChange);
 
   // The element that we're inspecting, and the document that it comes from.
@@ -602,14 +597,6 @@ CssComputedView.prototype = {
                                  CssLogic.FILTER.USER;
   },
 
-  _onSourcePrefChanged: function () {
-    this._handlePrefChange();
-    for (let propView of this.propertyViews) {
-      propView.updateSourceLinks();
-    }
-    this.inspector.emit("computed-view-sourcelinks-updated");
-  },
-
   /**
    * Render the box model view.
    */
@@ -753,7 +740,6 @@ CssComputedView.prototype = {
     this._viewedElement = null;
     this._outputParser = null;
 
-    this._prefObserver.off(PREF_ORIG_SOURCES, this._onSourcePrefChanged);
     this._prefObserver.off("devtools.defaultColorUnit", this._handlePrefChange);
     this._prefObserver.destroy();
 
@@ -1096,15 +1082,14 @@ PropertyView.prototype = {
         .getMatchedSelectors(this.tree._viewedElement, this.name)
         .then(matched => {
           if (!this.matchedExpanded) {
-            return promise.resolve(undefined);
+            return;
           }
 
           this._matchedSelectorResponse = matched;
 
-          return this._buildMatchedSelectors().then(() => {
-            this.matchedExpander.setAttribute("open", "");
-            this.tree.inspector.emit("computed-view-property-expanded");
-          });
+          this._buildMatchedSelectors();
+          this.matchedExpander.setAttribute("open", "");
+          this.tree.inspector.emit("computed-view-property-expanded");
         }).catch(console.error);
     }
 
@@ -1119,7 +1104,6 @@ PropertyView.prototype = {
   },
 
   _buildMatchedSelectors: function () {
-    let promises = [];
     let frag = this.element.ownerDocument.createDocumentFragment();
 
     for (let selector of this.matchedSelectorViews) {
@@ -1157,12 +1141,10 @@ PropertyView.prototype = {
         class: "fix-get-selection computed-other-property-value theme-fg-color1"
       });
       valueDiv.appendChild(selector.outputFragment);
-      promises.push(selector.ready);
     }
 
     this.matchedSelectorsContainer.innerHTML = "";
     this.matchedSelectorsContainer.appendChild(frag);
-    return promise.all(promises);
   },
 
   /**
@@ -1180,19 +1162,6 @@ PropertyView.prototype = {
     return this._matchedSelectorViews;
   },
 
-  /**
-   * Update all the selector source links to reflect whether we're linking to
-   * original sources (e.g. Sass files).
-   */
-  updateSourceLinks: function () {
-    if (!this._matchedSelectorViews) {
-      return;
-    }
-    for (let view of this._matchedSelectorViews) {
-      view.updateSourceLink();
-    }
-  },
-
   /**
    * The action when a user expands matched selectors.
    *
@@ -1225,6 +1194,12 @@ PropertyView.prototype = {
    * Destroy this property view, removing event listeners
    */
   destroy: function () {
+    if (this._matchedSelectorViews) {
+      for (let view of this._matchedSelectorViews) {
+        view.destroy();
+      }
+    }
+
     this.element.removeEventListener("dblclick", this.onMatchedToggle);
     this.shortcuts.destroy();
     this.element = null;
@@ -1253,8 +1228,26 @@ function SelectorView(tree, selectorInfo) {
   this._cacheStatusNames();
 
   this.openStyleEditor = this.openStyleEditor.bind(this);
+  this._updateLocation = this._updateLocation.bind(this);
 
-  this.ready = this.updateSourceLink();
+  const rule = this.selectorInfo.rule;
+  if (!rule || !rule.parentStyleSheet || rule.type == ELEMENT_STYLE) {
+    this.source = CssLogic.l10n("rule.sourceElement");
+  } else {
+    // This always refers to the generated location.
+    const sheet = rule.parentStyleSheet;
+    this.source = CssLogic.shortSource(sheet) + ":" + rule.line;
+
+    const url = sheet.href || sheet.nodeHref;
+    this.currentLocation = {
+      href: url,
+      line: rule.line,
+      column: rule.column,
+    };
+    this.generatedLocation = this.currentLocation;
+    this.sourceMapURLService = this.tree.inspector.toolbox.sourceMapURLService;
+    this.sourceMapURLService.subscribe(url, rule.line, rule.column, this._updateLocation);
+  }
 }
 
 /**
@@ -1344,50 +1337,43 @@ SelectorView.prototype = {
 
   /**
    * Update the text of the source link to reflect whether we're showing
-   * original sources or not.
+   * original sources or not.  This is a callback for
+   * SourceMapURLService.subscribe, which see.
+   *
+   * @param {Boolean} enabled
+   *        True if the passed-in location should be used; this means
+   *        that source mapping is in use and the remaining arguments
+   *        are the original location.  False if the already-known
+   *        (stored) location should be used.
+   * @param {String} url
+   *        The original URL
+   * @param {Number} line
+   *        The original line number
+   * @param {number} column
+   *        The original column number
    */
-  updateSourceLink: function () {
-    return this.updateSource().then((oldSource) => {
-      if (oldSource !== this.source && this.tree.element) {
-        let selector = '[sourcelocation="' + oldSource + '"]';
-        let link = this.tree.element.querySelector(selector);
-        if (link) {
-          link.textContent = this.source;
-          link.setAttribute("sourcelocation", this.source);
-        }
-      }
-    });
-  },
-
-  /**
-   * Update the 'source' store based on our original sources preference.
-   */
-  updateSource: function () {
-    let rule = this.selectorInfo.rule;
-    this.sheet = rule.parentStyleSheet;
-
-    if (!rule || !this.sheet) {
-      let oldSource = this.source;
-      this.source = CssLogic.l10n("rule.sourceElement");
-      return promise.resolve(oldSource);
+  _updateLocation: function (enabled, url, line, column) {
+    if (!this.tree.element) {
+      return;
     }
 
-    let showOrig = Services.prefs.getBoolPref(PREF_ORIG_SOURCES);
-
-    if (showOrig && rule.type !== ELEMENT_STYLE) {
-      // set as this first so we show something while we're fetching
-      this.source = CssLogic.shortSource(this.sheet) + ":" + rule.line;
-
-      return rule.getOriginalLocation().then(({href, line}) => {
-        let oldSource = this.source;
-        this.source = CssLogic.shortSource({href: href}) + ":" + line;
-        return oldSource;
-      });
+    // Update |currentLocation| to be whichever location is being
+    // displayed at the moment.
+    if (enabled) {
+      this.currentLocation = { href: url, line, column };
+    } else {
+      this.currentLocation = this.generatedLocation;
     }
 
-    let oldSource = this.source;
-    this.source = CssLogic.shortSource(this.sheet) + ":" + rule.line;
-    return promise.resolve(oldSource);
+    let selector = '[sourcelocation="' + this.source + '"]';
+    let link = this.tree.element.querySelector(selector);
+    if (link) {
+      let text = CssLogic.shortSource(this.currentLocation) +
+          ":" + this.currentLocation.line;
+      link.textContent = text;
+    }
+
+    this.tree.inspector.emit("computed-view-sourcelinks-updated");
   },
 
   /**
@@ -1414,21 +1400,26 @@ SelectorView.prototype = {
       return;
     }
 
-    let location = promise.resolve(rule.location);
-    if (Services.prefs.getBoolPref(PREF_ORIG_SOURCES)) {
-      location = rule.getOriginalLocation();
+    let {href, line, column} = this.currentLocation;
+    let target = inspector.target;
+    if (ToolDefinitions.styleEditor.isTargetSupported(target)) {
+      gDevTools.showToolbox(target, "styleeditor").then(function (toolbox) {
+        toolbox.getCurrentPanel().selectStyleSheet(href, line, column);
+      });
     }
+  },
 
-    location.then(({source, href, line, column}) => {
-      let target = inspector.target;
-      if (ToolDefinitions.styleEditor.isTargetSupported(target)) {
-        gDevTools.showToolbox(target, "styleeditor").then(function (toolbox) {
-          let sheet = source || href;
-          toolbox.getCurrentPanel().selectStyleSheet(sheet, line, column);
-        });
-      }
-    });
-  }
+  /**
+   * Destroy this selector view, removing event listeners
+   */
+  destroy: function () {
+    let rule = this.selectorInfo.rule;
+    if (rule && rule.parentStyleSheet && rule.type != ELEMENT_STYLE) {
+      const url = rule.parentStyleSheet.href || rule.parentStyleSheet.nodeHref;
+      this.sourceMapURLService.unsubscribe(url, rule.line,
+                                           rule.column, this._updateLocation);
+    }
+  },
 };
 
 function ComputedViewTool(inspector, window) {
diff --git a/devtools/client/inspector/computed/test/browser_computed_original-source-link.js b/devtools/client/inspector/computed/test/browser_computed_original-source-link.js
index 62b547a7d2b6..57503dac13ba 100644
--- a/devtools/client/inspector/computed/test/browser_computed_original-source-link.js
+++ b/devtools/client/inspector/computed/test/browser_computed_original-source-link.js
@@ -18,22 +18,18 @@ add_task(function* () {
 
   yield addTab(TESTCASE_URI);
   let {toolbox, inspector, view} = yield openComputedView();
+  let onLinksUpdated = inspector.once("computed-view-sourcelinks-updated");
   yield selectNode("div", inspector);
 
   info("Expanding the first property");
   yield expandComputedViewPropertyByIndex(view, 0);
 
   info("Verifying the link text");
-  // Forcing a call to updateSourceLink on the SelectorView here. The
-  // computed-view already does it, but we have no way of waiting for it to be
-  // done here, so just call it again and wait for the returned promise to
-  // resolve.
-  let propertyView = getComputedViewPropertyView(view, "color");
-  yield propertyView.matchedSelectorViews[0].updateSourceLink();
+  yield onLinksUpdated;
   verifyLinkText(view, SCSS_LOC);
 
   info("Toggling the pref");
-  let onLinksUpdated = inspector.once("computed-view-sourcelinks-updated");
+  onLinksUpdated = inspector.once("computed-view-sourcelinks-updated");
   Services.prefs.setBoolPref(PREF, false);
   yield onLinksUpdated;
 
diff --git a/devtools/client/inspector/rules/models/rule.js b/devtools/client/inspector/rules/models/rule.js
index 3edd99a0804e..ab3ab6de454f 100644
--- a/devtools/client/inspector/rules/models/rule.js
+++ b/devtools/client/inspector/rules/models/rule.js
@@ -117,7 +117,7 @@ Rule.prototype = {
    * The rule's line within a stylesheet
    */
   get ruleLine() {
-    return this.domRule ? this.domRule.line : "";
+    return this.domRule ? this.domRule.line : -1;
   },
 
   /**
@@ -127,36 +127,6 @@ Rule.prototype = {
     return this.domRule ? this.domRule.column : null;
   },
 
-  /**
-   * Get display name for this rule based on the original source
-   * for this rule's style sheet.
-   *
-   * @return {Promise}
-   *         Promise which resolves with location as an object containing
-   *         both the full and short version of the source string.
-   */
-  getOriginalSourceStrings: function () {
-    return this.domRule.getOriginalLocation().then(({href, line, mediaText}) => {
-      let mediaString = mediaText ? " @" + mediaText : "";
-      let linePart = line > 0 ? (":" + line) : "";
-      let decodedHref = href;
-
-      if (decodedHref) {
-        try {
-          decodedHref = decodeURIComponent(href);
-        } catch (e) {}
-      }
-
-      let sourceStrings = {
-        full: (decodedHref || CssLogic.l10n("rule.sourceInline")) + linePart +
-          mediaString,
-        short: CssLogic.shortSource({href: decodedHref}) + linePart + mediaString
-      };
-
-      return sourceStrings;
-    });
-  },
-
   /**
    * Returns true if the rule matches the creation options
    * specified.
diff --git a/devtools/client/inspector/rules/rules.js b/devtools/client/inspector/rules/rules.js
index feb6fb6e3a2d..528f840a2e66 100644
--- a/devtools/client/inspector/rules/rules.js
+++ b/devtools/client/inspector/rules/rules.js
@@ -9,7 +9,6 @@
 const promise = require("promise");
 const Services = require("Services");
 const {Task} = require("devtools/shared/task");
-const {Tools} = require("devtools/client/definitions");
 const {l10n} = require("devtools/shared/inspector/css-logic");
 const {ELEMENT_STYLE} = require("devtools/shared/specs/styles");
 const OutputParser = require("devtools/client/shared/output-parser");
@@ -18,7 +17,6 @@ const ElementStyle = require("devtools/client/inspector/rules/models/element-sty
 const Rule = require("devtools/client/inspector/rules/models/rule");
 const RuleEditor = require("devtools/client/inspector/rules/views/rule-editor");
 const ClassListPreviewer = require("devtools/client/inspector/rules/views/class-list-previewer");
-const {gDevTools} = require("devtools/client/framework/devtools");
 const {getCssProperties} = require("devtools/shared/fronts/css-properties");
 const {
   VIEW_NODE_SELECTOR_TYPE,
@@ -41,7 +39,6 @@ const HTML_NS = "http://www.w3.org/1999/xhtml";
 const PREF_UA_STYLES = "devtools.inspector.showUserAgentStyles";
 const PREF_DEFAULT_COLOR_UNIT = "devtools.defaultColorUnit";
 const FILTER_CHANGED_TIMEOUT = 150;
-const PREF_ORIG_SOURCES = "devtools.source-map.client-service.enabled";
 
 // This is used to parse user input when filtering.
 const FILTER_PROP_RE = /\s*([^:\s]*)\s*:\s*(.*?)\s*;?$/;
@@ -157,10 +154,8 @@ function CssRuleView(inspector, document, store, pageStyle) {
   this.focusCheckbox.addEventListener("click", this._onTogglePseudoClass);
 
   this._handlePrefChange = this._handlePrefChange.bind(this);
-  this._onSourcePrefChanged = this._onSourcePrefChanged.bind(this);
 
   this._prefObserver = new PrefObserver("devtools.");
-  this._prefObserver.on(PREF_ORIG_SOURCES, this._onSourcePrefChanged);
   this._prefObserver.on(PREF_UA_STYLES, this._handlePrefChange);
   this._prefObserver.on(PREF_DEFAULT_COLOR_UNIT, this._handlePrefChange);
 
@@ -557,20 +552,6 @@ CssRuleView.prototype = {
     }
   },
 
-  /**
-   * Update source links when pref for showing original sources changes
-   */
-  _onSourcePrefChanged: function () {
-    if (this._elementStyle && this._elementStyle.rules) {
-      for (let rule of this._elementStyle.rules) {
-        if (rule.editor) {
-          rule.editor.updateSourceLink();
-        }
-      }
-      this.inspector.emit("rule-view-sourcelinks-updated");
-    }
-  },
-
   /**
    * Set the filter style search value.
    * @param {String} value
@@ -682,7 +663,6 @@ CssRuleView.prototype = {
 
     this._dummyElement = null;
 
-    this._prefObserver.off(PREF_ORIG_SOURCES, this._onSourcePrefChanged);
     this._prefObserver.off(PREF_UA_STYLES, this._handlePrefChange);
     this._prefObserver.off(PREF_DEFAULT_COLOR_UNIT, this._handlePrefChange);
     this._prefObserver.destroy();
@@ -1606,7 +1586,6 @@ function RuleViewTool(inspector, window) {
 
   this.clearUserProperties = this.clearUserProperties.bind(this);
   this.refresh = this.refresh.bind(this);
-  this.onLinkClicked = this.onLinkClicked.bind(this);
   this.onMutations = this.onMutations.bind(this);
   this.onPanelSelected = this.onPanelSelected.bind(this);
   this.onPropertyChanged = this.onPropertyChanged.bind(this);
@@ -1616,7 +1595,6 @@ function RuleViewTool(inspector, window) {
 
   this.view.on("ruleview-changed", this.onPropertyChanged);
   this.view.on("ruleview-refreshed", this.onViewRefreshed);
-  this.view.on("ruleview-linked-clicked", this.onLinkClicked);
 
   this.inspector.selection.on("detached-front", this.onSelected);
   this.inspector.selection.on("new-node-front", this.onSelected);
@@ -1688,33 +1666,6 @@ RuleViewTool.prototype = {
     }
   },
 
-  onLinkClicked: function (e, rule) {
-    let sheet = rule.parentStyleSheet;
-
-    // Chrome stylesheets are not listed in the style editor, so show
-    // these sheets in the view source window instead.
-    if (!sheet || sheet.isSystem) {
-      let href = rule.nodeHref || rule.href;
-      let toolbox = gDevTools.getToolbox(this.inspector.target);
-      toolbox.viewSource(href, rule.line);
-      return;
-    }
-
-    let location = promise.resolve(rule.location);
-    if (Services.prefs.getBoolPref(PREF_ORIG_SOURCES)) {
-      location = rule.getOriginalLocation();
-    }
-    location.then(({ source, href, line, column }) => {
-      let target = this.inspector.target;
-      if (Tools.styleEditor.isTargetSupported(target)) {
-        gDevTools.showToolbox(target, "styleeditor").then(function (toolbox) {
-          let url = source || href;
-          toolbox.getCurrentPanel().selectStyleSheet(url, line, column);
-        });
-      }
-    });
-  },
-
   onPropertyChanged: function () {
     this.inspector.markDirty();
   },
@@ -1757,7 +1708,6 @@ RuleViewTool.prototype = {
       this.inspector.pageStyle.off("stylesheet-updated", this.refresh);
     }
 
-    this.view.off("ruleview-linked-clicked", this.onLinkClicked);
     this.view.off("ruleview-changed", this.onPropertyChanged);
     this.view.off("ruleview-refreshed", this.onViewRefreshed);
 
diff --git a/devtools/client/inspector/rules/views/rule-editor.js b/devtools/client/inspector/rules/views/rule-editor.js
index 74c4eb056294..33117c6c7ccd 100644
--- a/devtools/client/inspector/rules/views/rule-editor.js
+++ b/devtools/client/inspector/rules/views/rule-editor.js
@@ -27,25 +27,20 @@ const promise = require("promise");
 const Services = require("Services");
 const EventEmitter = require("devtools/shared/old-event-emitter");
 const {Task} = require("devtools/shared/task");
+const {Tools} = require("devtools/client/definitions");
+const {gDevTools} = require("devtools/client/framework/devtools");
+const CssLogic = require("devtools/shared/inspector/css-logic");
 
 const STYLE_INSPECTOR_PROPERTIES = "devtools/shared/locales/styleinspector.properties";
 const {LocalizationHelper} = require("devtools/shared/l10n");
 const STYLE_INSPECTOR_L10N = new LocalizationHelper(STYLE_INSPECTOR_PROPERTIES);
 
-const PREF_ORIG_SOURCES = "devtools.source-map.client-service.enabled";
-
 /**
  * RuleEditor is responsible for the following:
  *   Owns a Rule object and creates a list of TextPropertyEditors
  *     for its TextProperties.
  *   Manages creation of new text properties.
  *
- * One step of a RuleEditor's instantiation is figuring out what's the original
- * source link to the parent stylesheet (in case of source maps). This step is
- * asynchronous and is triggered as soon as the RuleEditor is instantiated (see
- * updateSourceLink). If you need to know when the RuleEditor is done with this,
- * you need to listen to the source-link-updated event.
- *
  * @param {CssRuleView} ruleView
  *        The CssRuleView containg the document holding this rule editor.
  * @param {Rule} rule
@@ -57,6 +52,9 @@ function RuleEditor(ruleView, rule) {
   this.ruleView = ruleView;
   this.doc = this.ruleView.styleDocument;
   this.toolbox = this.ruleView.inspector.toolbox;
+  // We stash this locally so that we can refer to it from |destroy|
+  // without accidentally reinstantiating the service during shutdown.
+  this.sourceMapURLService = this.toolbox.sourceMapURLService;
   this.rule = rule;
 
   this.isEditable = !rule.isSystem;
@@ -69,10 +67,13 @@ function RuleEditor(ruleView, rule) {
   this._onSelectorDone = this._onSelectorDone.bind(this);
   this._locationChanged = this._locationChanged.bind(this);
   this.updateSourceLink = this.updateSourceLink.bind(this);
+  this._onToolChanged = this._onToolChanged.bind(this);
+  this._updateLocation = this._updateLocation.bind(this);
+  this._onSourceClick = this._onSourceClick.bind(this);
 
   this.rule.domRule.on("location-changed", this._locationChanged);
-  this.toolbox.on("tool-registered", this.updateSourceLink);
-  this.toolbox.on("tool-unregistered", this.updateSourceLink);
+  this.toolbox.on("tool-registered", this._onToolChanged);
+  this.toolbox.on("tool-unregistered", this._onToolChanged);
 
   this._create();
 }
@@ -80,8 +81,21 @@ function RuleEditor(ruleView, rule) {
 RuleEditor.prototype = {
   destroy: function () {
     this.rule.domRule.off("location-changed");
-    this.toolbox.off("tool-registered", this.updateSourceLink);
-    this.toolbox.off("tool-unregistered", this.updateSourceLink);
+    this.toolbox.off("tool-registered", this._onToolChanged);
+    this.toolbox.off("tool-unregistered", this._onToolChanged);
+
+    let url = null;
+    if (this.rule.sheet) {
+      url = this.rule.sheet.href || this.rule.sheet.nodeHref;
+    }
+    if (url && !this.rule.isSystem && this.rule.domRule.type !== ELEMENT_STYLE) {
+      // Only get the original source link if the rule isn't a system
+      // rule and if it isn't an inline rule.
+      let sourceLine = this.rule.ruleLine;
+      let sourceColumn = this.rule.ruleColumn;
+      this.sourceMapURLService.unsubscribe(url, sourceLine, sourceColumn,
+                                           this._updateLocation);
+    }
   },
 
   get isSelectorEditable() {
@@ -110,13 +124,8 @@ RuleEditor.prototype = {
     this.source = createChild(this.element, "div", {
       class: "ruleview-rule-source theme-link"
     });
-    this.source.addEventListener("click", () => {
-      if (this.source.hasAttribute("unselectable")) {
-        return;
-      }
-      let rule = this.rule.domRule;
-      this.ruleView.emit("ruleview-linked-clicked", rule);
-    });
+    this.source.addEventListener("click", this._onSourceClick);
+
     let sourceLabel = this.doc.createElement("span");
     sourceLabel.classList.add("ruleview-rule-source-label");
     this.source.appendChild(sourceLabel);
@@ -225,6 +234,23 @@ RuleEditor.prototype = {
     }
   },
 
+  /**
+   * Called when a tool is registered or unregistered.
+   */
+  _onToolChanged: function () {
+    // When the source editor is registered, update the source links
+    // to be clickable; and if it is unregistered, update the links to
+    // be unclickable.  However, some links are never clickable, so
+    // filter those out first.
+    if (this.source.getAttribute("unselectable") === "permanent") {
+      // Nothing.
+    } else if (this.toolbox.isToolRegistered("styleeditor")) {
+      this.source.removeAttribute("unselectable");
+    } else {
+      this.source.setAttribute("unselectable", "true");
+    }
+  },
+
   /**
    * Event handler called when a property changes on the
    * StyleRuleActor.
@@ -233,22 +259,76 @@ RuleEditor.prototype = {
     this.updateSourceLink();
   },
 
-  updateSourceLink: function () {
-    let sourceLabel = this.element.querySelector(".ruleview-rule-source-label");
-    let title = this.rule.title;
-    let sourceHref = (this.rule.sheet && this.rule.sheet.href) ?
-      this.rule.sheet.href : title;
-    let sourceLine = this.rule.ruleLine > 0 ? ":" + this.rule.ruleLine : "";
-
-    sourceLabel.setAttribute("title", sourceHref + sourceLine);
-
-    if (this.toolbox.isToolRegistered("styleeditor")) {
-      this.source.removeAttribute("unselectable");
-    } else {
-      this.source.setAttribute("unselectable", true);
+  _onSourceClick: function () {
+    if (this.source.hasAttribute("unselectable") || !this._currentLocation) {
+      return;
     }
 
+    let target = this.ruleView.inspector.target;
+    if (Tools.styleEditor.isTargetSupported(target)) {
+      gDevTools.showToolbox(target, "styleeditor").then(toolbox => {
+        let {url, line, column} = this._currentLocation;
+        toolbox.getCurrentPanel().selectStyleSheet(url, line, column);
+      });
+    }
+  },
+
+  /**
+   * Update the text of the source link to reflect whether we're showing
+   * original sources or not.  This is a callback for
+   * SourceMapURLService.subscribe, which see.
+   *
+   * @param {Boolean} enabled
+   *        True if the passed-in location should be used; this means
+   *        that source mapping is in use and the remaining arguments
+   *        are the original location.  False if the already-known
+   *        (stored) location should be used.
+   * @param {String} url
+   *        The original URL
+   * @param {Number} line
+   *        The original line number
+   * @param {number} column
+   *        The original column number
+   */
+  _updateLocation: function (enabled, url, line, column) {
+    let displayURL = url;
+    if (!enabled) {
+      url = null;
+      displayURL = null;
+      if (this.rule.sheet) {
+        url = this.rule.sheet.href || this.rule.sheet.nodeHref;
+        displayURL = this.rule.sheet.href;
+      }
+      line = this.rule.ruleLine;
+      column = this.rule.ruleColumn;
+    }
+
+    this._currentLocation = {
+      url,
+      line,
+      column
+    };
+
+    let title = CssLogic.shortSource({href: displayURL});
+    if (line > 0) {
+      title += ":" + line;
+    }
+    if (this.rule.mediaText) {
+      title += " @" + this.rule.mediaText;
+    }
+
+    let sourceLabel = this.element.querySelector(".ruleview-rule-source-label");
+    sourceLabel.setAttribute("title", title);
+    sourceLabel.textContent = title;
+  },
+
+  updateSourceLink: function () {
     if (this.rule.isSystem) {
+      let sourceLabel = this.element.querySelector(".ruleview-rule-source-label");
+      let title = this.rule.title;
+      let sourceHref = (this.rule.sheet && this.rule.sheet.href) ?
+          this.rule.sheet.href : title;
+
       let uaLabel = STYLE_INSPECTOR_L10N.getStr("rule.userAgentStyles");
       sourceLabel.textContent = uaLabel + " " + title;
 
@@ -256,36 +336,37 @@ RuleEditor.prototype = {
       // fly and the URI is not registered with the about: handler.
       // https://bugzilla.mozilla.org/show_bug.cgi?id=935803#c37
       if (sourceHref === "about:PreferenceStyleSheet") {
-        this.source.setAttribute("unselectable", "true");
+        this.source.setAttribute("unselectable", "permanent");
         sourceLabel.textContent = uaLabel;
         sourceLabel.removeAttribute("title");
       }
     } else {
-      sourceLabel.textContent = title;
-      if (this.rule.ruleLine === -1 && this.rule.domRule.parentStyleSheet) {
-        this.source.setAttribute("unselectable", "true");
-      }
+      this._updateLocation(false);
     }
 
-    let showOrig = Services.prefs.getBoolPref(PREF_ORIG_SOURCES);
-    if (showOrig && !this.rule.isSystem &&
-        this.rule.domRule.type !== ELEMENT_STYLE) {
-      // Only get the original source link if the right pref is set, if the rule
-      // isn't a system rule and if it isn't an inline rule.
-      this.rule.getOriginalSourceStrings().then((strings) => {
-        sourceLabel.textContent = strings.short;
-        sourceLabel.setAttribute("title", strings.full);
-      }, console.error).then(() => {
-        this.emit("source-link-updated");
-      });
-    } else {
-      // If we're not getting the original source link, then we can emit the
-      // event immediately (but still asynchronously to give consumers a chance
-      // to register it after having instantiated the RuleEditor).
-      promise.resolve().then(() => {
-        this.emit("source-link-updated");
-      });
+    let url = null;
+    if (this.rule.sheet) {
+      url = this.rule.sheet.href || this.rule.sheet.nodeHref;
     }
+    if (url && !this.rule.isSystem && this.rule.domRule.type !== ELEMENT_STYLE) {
+      // Only get the original source link if the rule isn't a system
+      // rule and if it isn't an inline rule.
+      let sourceLine = this.rule.ruleLine;
+      let sourceColumn = this.rule.ruleColumn;
+      this.sourceMapURLService.subscribe(url, sourceLine, sourceColumn,
+                                         this._updateLocation);
+      // Set "unselectable" appropriately.
+      this._onToolChanged();
+    } else if (this.rule.domRule.type === ELEMENT_STYLE) {
+      this.source.setAttribute("unselectable", "permanent");
+    } else {
+      // Set "unselectable" appropriately.
+      this._onToolChanged();
+    }
+
+    promise.resolve().then(() => {
+      this.emit("source-link-updated");
+    });
   },
 
   /**
diff --git a/devtools/client/locales/en-US/netmonitor.properties b/devtools/client/locales/en-US/netmonitor.properties
index 1f297c66511d..e910fbd8b428 100644
--- a/devtools/client/locales/en-US/netmonitor.properties
+++ b/devtools/client/locales/en-US/netmonitor.properties
@@ -648,6 +648,10 @@ netmonitor.toolbar.disableCache.tooltip=Disable HTTP cache
 # in the network toolbar for the "Clear" button.
 netmonitor.toolbar.clear=Clear
 
+# LOCALIZATION NOTE (netmonitor.toolbar.toggleRecording): This is the label displayed
+# in the network toolbar for the toggle recording button.
+netmonitor.toolbar.toggleRecording=Pause/Resume recording network log
+
 # LOCALIZATION NOTE (netmonitor.toolbar.perf): This is the label displayed
 # in the network toolbar for the performance analysis button.
 netmonitor.toolbar.perf=Toggle performance analysis…
diff --git a/devtools/client/locales/en-US/performance.dtd b/devtools/client/locales/en-US/performance.dtd
index 4009ae10450f..5b5c1eda045a 100644
--- a/devtools/client/locales/en-US/performance.dtd
+++ b/devtools/client/locales/en-US/performance.dtd
@@ -15,11 +15,6 @@
   -  is displayed as the tooltip for the buffer capacity during a recording. -->
 <!ENTITY performanceUI.bufferStatusTooltip "The profiler stores samples in a circular buffer, and once the buffer reaches the limit for a recording, newer samples begin to overwrite samples at the beginning of the recording.">
 
-<!-- LOCALIZATION NOTE (performanceUI.disabledRealTime.nonE10SBuild): This string
-  -  is displayed as a message for why the real time overview graph is disabled
-  -  when running on a non-multiprocess build. -->
-<!ENTITY performanceUI.disabledRealTime.nonE10SBuild "Realtime recording data disabled on non-multiprocess Firefox.">
-
 <!-- LOCALIZATION NOTE (performanceUI.disabledRealTime.disabledE10S): This string
   -  is displayed as a message for why the real time overview graph is disabled
   -  when running on a build that can run multiprocess Firefox, but just is not enabled. -->
diff --git a/devtools/client/netmonitor/index.html b/devtools/client/netmonitor/index.html
index dbae940c0ae0..90bc9d929dee 100644
--- a/devtools/client/netmonitor/index.html
+++ b/devtools/client/netmonitor/index.html
@@ -14,7 +14,8 @@
     <script>
       "use strict";
 
-      const { BrowserLoader } = Components.utils.import("resource://devtools/client/shared/browser-loader.js", {});
+      const { BrowserLoader } = Components.utils.import(
+        "resource://devtools/client/shared/browser-loader.js", {});
       const require = window.windowRequire = BrowserLoader({
         baseURI: "resource://devtools/client/netmonitor/",
         window,
@@ -25,15 +26,23 @@
       const { render, unmountComponentAtNode } = require("devtools/client/shared/vendor/react-dom");
       const Provider = createFactory(require("devtools/client/shared/vendor/react-redux").Provider);
       const { bindActionCreators } = require("devtools/client/shared/vendor/redux");
+      const { Connector } = require("./src/connector/index");
       const { configureStore } = require("./src/utils/create-store");
-      const store = configureStore();
-      const actions = bindActionCreators(require("./src/actions/index"), store.dispatch);
-      const { onFirefoxConnect, onDisconnect } = require("./src/connector/index");
+      const App = createFactory(require("./src/components/app"));
+      const { getDisplayedRequestById } = require("./src/selectors/index");
+      const { EVENTS } = require("./src/constants");
 
       // Inject EventEmitter into global window.
       EventEmitter.decorate(window);
+
+      // Configure store/state object.
+      let connector = new Connector();
+      const store = configureStore(connector);
+      const actions = bindActionCreators(require("./src/actions/index"), store.dispatch);
+
       // Inject to global window for testing
       window.store = store;
+      window.connector = connector;
 
       window.Netmonitor = {
         bootstrap({ toolbox }) {
@@ -53,17 +62,57 @@
             top.openUILinkIn(link, "tab");
           };
 
-          const App = createFactory(require("./src/components/app"));
+          // Render the root Application component.
           const sourceMapService = toolbox.sourceMapURLService;
-          const app = App({ sourceMapService, openLink });
+          const app = App({ connector, openLink, sourceMapService });
           render(Provider({ store }, app), this.mount);
-          return onFirefoxConnect(connection, actions, store.getState);
+
+          // Connect to the Firefox backend by default.
+          return connector.connectFirefox(connection, actions, store.getState);
         },
 
         destroy() {
           unmountComponentAtNode(this.mount);
-          return onDisconnect();
+          return connector.disconnect();
         },
+
+        /**
+         * Selects the specified request in the waterfall and opens the details view.
+         * This is a firefox toolbox specific API, which providing an ability to inspect
+         * a network request directly from other internal toolbox panel.
+         *
+         * @param {string} requestId The actor ID of the request to inspect.
+         * @return {object} A promise resolved once the task finishes.
+         */
+        inspectRequest(requestId) {
+          // Look for the request in the existing ones or wait for it to appear, if
+          // the network monitor is still loading.
+          return new Promise((resolve) => {
+            let request = null;
+            let inspector = () => {
+              request = getDisplayedRequestById(store.getState(), requestId);
+              if (!request) {
+                // Reset filters so that the request is visible.
+                actions.toggleRequestFilterType("all");
+                request = getDisplayedRequestById(store.getState(), requestId);
+              }
+
+              // If the request was found, select it. Otherwise this function will be
+              // called again once new requests arrive.
+              if (request) {
+                window.off(EVENTS.REQUEST_ADDED, inspector);
+                actions.selectRequest(request.id);
+                resolve();
+              }
+            };
+
+            inspector();
+
+            if (!request) {
+              window.on(EVENTS.REQUEST_ADDED, inspector);
+            }
+          });
+        }
       };
 
       // Implement support for:
diff --git a/devtools/client/netmonitor/index.js b/devtools/client/netmonitor/index.js
index 25fb944ddf9e..d665a52a4b19 100644
--- a/devtools/client/netmonitor/index.js
+++ b/devtools/client/netmonitor/index.js
@@ -13,7 +13,6 @@ const React = require("react");
 const ReactDOM = require("react-dom");
 const { bindActionCreators } = require("redux");
 const { bootstrap, renderRoot } = require("devtools-launchpad");
-const EventEmitter = require("devtools-modules/src/utils/event-emitter");
 const { Services: { appinfo, pref }} = require("devtools-modules");
 
 // Initialize preferences as early as possible
@@ -39,15 +38,17 @@ pref("devtools.netmonitor.har.enableAutoExportToFile", false);
 pref("devtools.netmonitor.persistlog", false);
 pref("devtools.styleeditor.enabled", true);
 
-const { configureStore } = require("./src/utils/create-store");
-
 require("./src/assets/styles/netmonitor.css");
 
+const EventEmitter = require("devtools-modules/src/utils/event-emitter");
 EventEmitter.decorate(window);
+
+const { configureStore } = require("./src/utils/create-store");
 const App = require("./src/components/app");
-const store = configureStore();
+const { Connector } = require("./src/connector/index");
+const connector = new Connector();
+const store = configureStore(connector);
 const actions = bindActionCreators(require("./src/actions"), store.dispatch);
-const { onConnect } = require("./src/connector");
 
 // Inject to global window for testing
 window.store = store;
@@ -80,6 +81,7 @@ bootstrap(React, ReactDOM).then((connection) => {
   if (!connection) {
     return;
   }
-  renderRoot(React, ReactDOM, App, store);
-  onConnect(connection, actions, store.getState);
+
+  renderRoot(React, ReactDOM, App, store, {connector});
+  connector.connect(connection, actions, store.getState);
 });
diff --git a/devtools/client/netmonitor/src/actions/requests.js b/devtools/client/netmonitor/src/actions/requests.js
index 193c32de5b45..4e7d45c328d4 100644
--- a/devtools/client/netmonitor/src/actions/requests.js
+++ b/devtools/client/netmonitor/src/actions/requests.js
@@ -4,13 +4,13 @@
 
 "use strict";
 
-const { sendHTTPRequest } = require("../connector/index");
 const {
   ADD_REQUEST,
   CLEAR_REQUESTS,
   CLONE_SELECTED_REQUEST,
   REMOVE_SELECTED_CUSTOM_REQUEST,
   SEND_CUSTOM_REQUEST,
+  TOGGLE_RECORDING,
   UPDATE_REQUEST,
 } = require("../constants");
 const { getSelectedRequest } = require("../selectors/index");
@@ -46,7 +46,7 @@ function cloneSelectedRequest() {
 /**
  * Send a new HTTP request using the data in the custom request form.
  */
-function sendCustomRequest() {
+function sendCustomRequest(connector) {
   return (dispatch, getState) => {
     const selected = getSelectedRequest(getState());
 
@@ -67,7 +67,7 @@ function sendCustomRequest() {
       data.body = selected.requestPostData.postData.text;
     }
 
-    sendHTTPRequest(data, (response) => {
+    connector.sendHTTPRequest(data, (response) => {
       return dispatch({
         type: SEND_CUSTOM_REQUEST,
         id: response.eventActor.actor,
@@ -92,11 +92,21 @@ function clearRequests() {
   };
 }
 
+/**
+ * Toggle monitoring
+ */
+function toggleRecording() {
+  return {
+    type: TOGGLE_RECORDING
+  };
+}
+
 module.exports = {
   addRequest,
   clearRequests,
   cloneSelectedRequest,
   removeSelectedCustomRequest,
   sendCustomRequest,
+  toggleRecording,
   updateRequest,
 };
diff --git a/devtools/client/netmonitor/src/actions/ui.js b/devtools/client/netmonitor/src/actions/ui.js
index 67b15ef10701..05b15b8e185e 100644
--- a/devtools/client/netmonitor/src/actions/ui.js
+++ b/devtools/client/netmonitor/src/actions/ui.js
@@ -15,7 +15,6 @@ const {
   TOGGLE_COLUMN,
   WATERFALL_RESIZE,
 } = require("../constants");
-const { triggerActivity } = require("../connector/index");
 
 /**
  * Change network details panel.
@@ -56,11 +55,12 @@ function disableBrowserCache(disabled) {
 /**
  * Change performance statistics panel open state.
  *
+ * @param {Object} connector - connector object to the backend
  * @param {boolean} visible - expected performance statistics panel open state
  */
-function openStatistics(open) {
+function openStatistics(connector, open) {
   if (open) {
-    triggerActivity(ACTIVITY_TYPE.RELOAD.WITH_CACHE_ENABLED);
+    connector.triggerActivity(ACTIVITY_TYPE.RELOAD.WITH_CACHE_ENABLED);
   }
   return {
     type: OPEN_STATISTICS,
@@ -139,9 +139,9 @@ function toggleBrowserCache() {
 /**
  * Toggle performance statistics panel.
  */
-function toggleStatistics() {
+function toggleStatistics(connector) {
   return (dispatch, getState) =>
-    dispatch(openStatistics(!getState().ui.statisticsOpen));
+    dispatch(openStatistics(connector, !getState().ui.statisticsOpen));
 }
 
 module.exports = {
diff --git a/devtools/client/netmonitor/src/assets/styles/netmonitor.css b/devtools/client/netmonitor/src/assets/styles/netmonitor.css
index c2043695922a..be905948d8ad 100644
--- a/devtools/client/netmonitor/src/assets/styles/netmonitor.css
+++ b/devtools/client/netmonitor/src/assets/styles/netmonitor.css
@@ -50,6 +50,12 @@
   --sort-descending-image: url(chrome://devtools/skin/images/firebug/arrow-down.svg);
 }
 
+/* Icons */
+:root {
+  --play-icon-url: url("chrome://devtools/skin/images/play.svg");
+  --pause-icon-url: url("chrome://devtools/skin/images/pause.svg");
+}
+
 /* General */
 
 * {
@@ -97,6 +103,14 @@ body,
   flex-wrap: wrap;
 }
 
+.devtools-button.devtools-pause-icon::before {
+  background-image: var(--pause-icon-url);
+}
+
+.devtools-button.devtools-play-icon::before {
+  background-image: var(--play-icon-url);
+}
+
 /* Learn more links */
 
 .learn-more-link::before {
diff --git a/devtools/client/netmonitor/src/components/app.js b/devtools/client/netmonitor/src/components/app.js
index f0bccc68409d..8b417372df32 100644
--- a/devtools/client/netmonitor/src/components/app.js
+++ b/devtools/client/netmonitor/src/components/app.js
@@ -17,18 +17,25 @@ const StatisticsPanel = createFactory(require("./statistics-panel"));
 
 const { div } = DOM;
 
-/*
+/**
  * App component
  * The top level component for representing main panel
  */
 function App({
+  connector,
   openLink,
   sourceMapService,
   statisticsOpen,
 }) {
   return (
     div({ className: "network-monitor" },
-      !statisticsOpen ? MonitorPanel({ openLink, sourceMapService }) : StatisticsPanel()
+      !statisticsOpen ? MonitorPanel({
+        connector,
+        sourceMapService,
+        openLink,
+      }) : StatisticsPanel({
+        connector
+      })
     )
   );
 }
@@ -36,9 +43,13 @@ function App({
 App.displayName = "App";
 
 App.propTypes = {
+  // The backend connector object.
+  connector: PropTypes.object.isRequired,
+  // Callback for opening links in the UI
   openLink: PropTypes.func,
   // Service to enable the source map feature.
   sourceMapService: PropTypes.object,
+  // True if the stats panel is opened.
   statisticsOpen: PropTypes.bool.isRequired,
 };
 
diff --git a/devtools/client/netmonitor/src/components/custom-request-panel.js b/devtools/client/netmonitor/src/components/custom-request-panel.js
index a5e6a3493a95..60cdf608e310 100644
--- a/devtools/client/netmonitor/src/components/custom-request-panel.js
+++ b/devtools/client/netmonitor/src/components/custom-request-panel.js
@@ -148,6 +148,7 @@ function CustomRequestPanel({
 CustomRequestPanel.displayName = "CustomRequestPanel";
 
 CustomRequestPanel.propTypes = {
+  connector: PropTypes.object.isRequired,
   removeSelectedCustomRequest: PropTypes.func.isRequired,
   request: PropTypes.object,
   sendCustomRequest: PropTypes.func.isRequired,
@@ -249,9 +250,9 @@ function updateCustomRequestFields(evt, request, updateRequest) {
 
 module.exports = connect(
   (state) => ({ request: getSelectedRequest(state) }),
-  (dispatch) => ({
+  (dispatch, props) => ({
     removeSelectedCustomRequest: () => dispatch(Actions.removeSelectedCustomRequest()),
-    sendCustomRequest: () => dispatch(Actions.sendCustomRequest()),
+    sendCustomRequest: () => dispatch(Actions.sendCustomRequest(props.connector)),
     updateRequest: (id, data, batch) => dispatch(Actions.updateRequest(id, data, batch)),
   })
 )(CustomRequestPanel);
diff --git a/devtools/client/netmonitor/src/components/monitor-panel.js b/devtools/client/netmonitor/src/components/monitor-panel.js
index 43d6921106e6..7224a1fef4d1 100644
--- a/devtools/client/netmonitor/src/components/monitor-panel.js
+++ b/devtools/client/netmonitor/src/components/monitor-panel.js
@@ -14,7 +14,6 @@ const {
 const { connect } = require("devtools/client/shared/vendor/react-redux");
 const { findDOMNode } = require("devtools/client/shared/vendor/react-dom");
 const Actions = require("../actions/index");
-const { getLongString } = require("../connector/index");
 const { getFormDataSections } = require("../utils/request-utils");
 const { getSelectedRequest } = require("../selectors/index");
 
@@ -26,7 +25,7 @@ const Toolbar = createFactory(require("./toolbar"));
 const { div } = DOM;
 const MediaQueryList = window.matchMedia("(min-width: 700px)");
 
-/*
+/**
  * Monitor panel component
  * The main panel for displaying various network request information
  */
@@ -34,11 +33,11 @@ const MonitorPanel = createClass({
   displayName: "MonitorPanel",
 
   propTypes: {
+    connector: PropTypes.object.isRequired,
     isEmpty: PropTypes.bool.isRequired,
     networkDetailsOpen: PropTypes.bool.isRequired,
     openNetworkDetails: PropTypes.func.isRequired,
     request: PropTypes.object,
-    // Service to enable the source map feature.
     sourceMapService: PropTypes.object,
     openLink: PropTypes.func,
     updateRequest: PropTypes.func.isRequired,
@@ -72,7 +71,7 @@ const MonitorPanel = createClass({
         requestHeaders,
         requestHeadersFromUploadStream,
         requestPostData,
-        getLongString,
+        this.props.connector.getLongString,
       ).then((newFormDataSections) => {
         updateRequest(
           request.id,
@@ -106,6 +105,7 @@ const MonitorPanel = createClass({
 
   render() {
     let {
+      connector,
       isEmpty,
       networkDetailsOpen,
       sourceMapService,
@@ -126,9 +126,10 @@ const MonitorPanel = createClass({
           minSize: "50px",
           maxSize: "80%",
           splitterSize: "1px",
-          startPanel: RequestList({ isEmpty }),
+          startPanel: RequestList({ isEmpty, connector }),
           endPanel: networkDetailsOpen && NetworkDetailsPanel({
             ref: "endPanel",
+            connector,
             sourceMapService,
             openLink,
           }),
diff --git a/devtools/client/netmonitor/src/components/network-details-panel.js b/devtools/client/netmonitor/src/components/network-details-panel.js
index f43546b04597..feac6fd5fa88 100644
--- a/devtools/client/netmonitor/src/components/network-details-panel.js
+++ b/devtools/client/netmonitor/src/components/network-details-panel.js
@@ -19,10 +19,11 @@ const TabboxPanel = createFactory(require("./tabbox-panel"));
 
 const { div } = DOM;
 
-/*
+/**
  * Network details panel component
  */
 function NetworkDetailsPanel({
+  connector,
   activeTabId,
   cloneSelectedRequest,
   request,
@@ -40,12 +41,14 @@ function NetworkDetailsPanel({
         TabboxPanel({
           activeTabId,
           cloneSelectedRequest,
+          connector,
+          openLink,
           request,
           selectTab,
           sourceMapService,
-          openLink,
         }) :
         CustomRequestPanel({
+          connector,
           request,
         })
     )
@@ -55,12 +58,12 @@ function NetworkDetailsPanel({
 NetworkDetailsPanel.displayName = "NetworkDetailsPanel";
 
 NetworkDetailsPanel.propTypes = {
+  connector: PropTypes.object.isRequired,
   activeTabId: PropTypes.string,
   cloneSelectedRequest: PropTypes.func.isRequired,
   open: PropTypes.bool,
   request: PropTypes.object,
   selectTab: PropTypes.func.isRequired,
-  // Service to enable the source map feature.
   sourceMapService: PropTypes.object,
   openLink: PropTypes.func,
 };
diff --git a/devtools/client/netmonitor/src/components/request-list-content.js b/devtools/client/netmonitor/src/components/request-list-content.js
index b9db36762eb1..e9218fda6060 100644
--- a/devtools/client/netmonitor/src/components/request-list-content.js
+++ b/devtools/client/netmonitor/src/components/request-list-content.js
@@ -35,6 +35,7 @@ const RequestListContent = createClass({
   displayName: "RequestListContent",
 
   propTypes: {
+    connector: PropTypes.object.isRequired,
     columns: PropTypes.object.isRequired,
     dispatch: PropTypes.func.isRequired,
     displayedRequests: PropTypes.object.isRequired,
@@ -51,10 +52,12 @@ const RequestListContent = createClass({
   },
 
   componentWillMount() {
-    const { dispatch } = this.props;
+    const { dispatch, connector } = this.props;
     this.contextMenu = new RequestListContextMenu({
       cloneSelectedRequest: () => dispatch(Actions.cloneSelectedRequest()),
-      openStatistics: (open) => dispatch(Actions.openStatistics(open)),
+      getTabTarget: connector.getTabTarget,
+      getLongString: connector.getLongString,
+      openStatistics: (open) => dispatch(Actions.openStatistics(connector, open)),
     });
     this.tooltip = new HTMLTooltip(window.parent.document, { type: "arrow" });
   },
@@ -156,8 +159,9 @@ const RequestListContent = createClass({
       return false;
     }
 
+    let { connector } = this.props;
     if (requestItem.responseContent && target.closest(".requests-list-icon")) {
-      return setTooltipImageContent(tooltip, itemEl, requestItem);
+      return setTooltipImageContent(connector, tooltip, itemEl, requestItem);
     }
 
     return false;
diff --git a/devtools/client/netmonitor/src/components/request-list-empty-notice.js b/devtools/client/netmonitor/src/components/request-list-empty-notice.js
index 9b120c323a4e..31cd134b70b5 100644
--- a/devtools/client/netmonitor/src/components/request-list-empty-notice.js
+++ b/devtools/client/netmonitor/src/components/request-list-empty-notice.js
@@ -12,7 +12,6 @@ const {
 } = require("devtools/client/shared/vendor/react");
 const { connect } = require("devtools/client/shared/vendor/react-redux");
 const Actions = require("../actions/index");
-const { triggerActivity } = require("../connector/index");
 const { ACTIVITY_TYPE } = require("../constants");
 const { L10N } = require("../utils/l10n");
 const { getPerformanceAnalysisURL } = require("../utils/mdn-utils");
@@ -37,6 +36,7 @@ const RequestListEmptyNotice = createClass({
   displayName: "RequestListEmptyNotice",
 
   propTypes: {
+    connector: PropTypes.object.isRequired,
     onReloadClick: PropTypes.func.isRequired,
     onPerfClick: PropTypes.func.isRequired,
   },
@@ -75,8 +75,9 @@ const RequestListEmptyNotice = createClass({
 
 module.exports = connect(
   undefined,
-  dispatch => ({
-    onPerfClick: () => dispatch(Actions.openStatistics(true)),
-    onReloadClick: () => triggerActivity(ACTIVITY_TYPE.RELOAD.WITH_CACHE_DEFAULT),
+  (dispatch, props) => ({
+    onPerfClick: () => dispatch(Actions.openStatistics(props.connector, true)),
+    onReloadClick: () => props.connector.triggerActivity(
+      ACTIVITY_TYPE.RELOAD.WITH_CACHE_DEFAULT),
   })
 )(RequestListEmptyNotice);
diff --git a/devtools/client/netmonitor/src/components/request-list.js b/devtools/client/netmonitor/src/components/request-list.js
index d2c8c724319a..6f3cb784319b 100644
--- a/devtools/client/netmonitor/src/components/request-list.js
+++ b/devtools/client/netmonitor/src/components/request-list.js
@@ -21,12 +21,15 @@ const { div } = DOM;
 /**
  * Request panel component
  */
-function RequestList({ isEmpty }) {
+function RequestList({
+  connector,
+  isEmpty,
+}) {
   return (
     div({ className: "request-list-container" },
       RequestListHeader(),
-      isEmpty ? RequestListEmptyNotice() : RequestListContent(),
-      StatusBar(),
+      isEmpty ? RequestListEmptyNotice({connector}) : RequestListContent({connector}),
+      StatusBar({connector}),
     )
   );
 }
@@ -34,6 +37,7 @@ function RequestList({ isEmpty }) {
 RequestList.displayName = "RequestList";
 
 RequestList.propTypes = {
+  connector: PropTypes.object.isRequired,
   isEmpty: PropTypes.bool.isRequired,
 };
 
diff --git a/devtools/client/netmonitor/src/components/stack-trace-panel.js b/devtools/client/netmonitor/src/components/stack-trace-panel.js
index 737641d847d2..43244973a33a 100644
--- a/devtools/client/netmonitor/src/components/stack-trace-panel.js
+++ b/devtools/client/netmonitor/src/components/stack-trace-panel.js
@@ -9,14 +9,18 @@ const {
   DOM,
   PropTypes,
 } = require("devtools/client/shared/vendor/react");
-const { viewSourceInDebugger } = require("../connector/index");
 
 const { div } = DOM;
 
 // Components
 const StackTrace = createFactory(require("devtools/client/shared/components/StackTrace"));
 
+/**
+ * This component represents a side panel responsible for
+ * rendering stack-trace info for selected request.
+ */
 function StackTracePanel({
+  connector,
   openLink,
   request,
   sourceMapService,
@@ -27,7 +31,9 @@ function StackTracePanel({
     div({ className: "panel-container" },
       StackTrace({
         stacktrace,
-        onViewSourceInDebugger: ({ url, line }) => viewSourceInDebugger(url, line),
+        onViewSourceInDebugger: ({ url, line }) => {
+          return connector.viewSourceInDebugger(url, line);
+        },
         sourceMapService,
         openLink,
       }),
@@ -38,8 +44,8 @@ function StackTracePanel({
 StackTracePanel.displayName = "StackTracePanel";
 
 StackTracePanel.propTypes = {
+  connector: PropTypes.object.isRequired,
   request: PropTypes.object.isRequired,
-  // Service to enable the source map feature.
   sourceMapService: PropTypes.object,
   openLink: PropTypes.func,
 };
diff --git a/devtools/client/netmonitor/src/components/statistics-panel.js b/devtools/client/netmonitor/src/components/statistics-panel.js
index 3c741864d244..0273ba107888 100644
--- a/devtools/client/netmonitor/src/components/statistics-panel.js
+++ b/devtools/client/netmonitor/src/components/statistics-panel.js
@@ -44,6 +44,7 @@ const StatisticsPanel = createClass({
   displayName: "StatisticsPanel",
 
   propTypes: {
+    connector: PropTypes.object.isRequired,
     closeStatistics: PropTypes.func.isRequired,
     enableRequestFilterTypeOnly: PropTypes.func.isRequired,
     requests: PropTypes.object,
@@ -302,8 +303,8 @@ module.exports = connect(
   (state) => ({
     requests: state.requests.requests.valueSeq(),
   }),
-  (dispatch) => ({
-    closeStatistics: () => dispatch(Actions.openStatistics(false)),
+  (dispatch, props) => ({
+    closeStatistics: () => dispatch(Actions.openStatistics(props.connector, false)),
     enableRequestFilterTypeOnly: (label) =>
       dispatch(Actions.enableRequestFilterTypeOnly(label)),
   })
diff --git a/devtools/client/netmonitor/src/components/status-bar.js b/devtools/client/netmonitor/src/components/status-bar.js
index bc3c8dea8d0f..2302d98fded0 100644
--- a/devtools/client/netmonitor/src/components/status-bar.js
+++ b/devtools/client/netmonitor/src/components/status-bar.js
@@ -88,6 +88,7 @@ function StatusBar({ summary, openStatistics, timingMarkers }) {
 StatusBar.displayName = "StatusBar";
 
 StatusBar.propTypes = {
+  connector: PropTypes.object.isRequired,
   openStatistics: PropTypes.func.isRequired,
   summary: PropTypes.object.isRequired,
   timingMarkers: PropTypes.object.isRequired,
@@ -102,7 +103,7 @@ module.exports = connect(
       load: getDisplayedTimingMarker(state, "firstDocumentLoadTimestamp"),
     },
   }),
-  (dispatch) => ({
-    openStatistics: () => dispatch(Actions.openStatistics(true)),
+  (dispatch, props) => ({
+    openStatistics: () => dispatch(Actions.openStatistics(props.connector, true)),
   }),
 )(StatusBar);
diff --git a/devtools/client/netmonitor/src/components/tabbox-panel.js b/devtools/client/netmonitor/src/components/tabbox-panel.js
index c8a29178873e..af7de884c8c2 100644
--- a/devtools/client/netmonitor/src/components/tabbox-panel.js
+++ b/devtools/client/netmonitor/src/components/tabbox-panel.js
@@ -31,17 +31,18 @@ const SECURITY_TITLE = L10N.getStr("netmonitor.tab.security");
 const STACK_TRACE_TITLE = L10N.getStr("netmonitor.tab.stackTrace");
 const TIMINGS_TITLE = L10N.getStr("netmonitor.tab.timings");
 
-/*
+/**
  * Tabbox panel component
  * Display the network request details
  */
 function TabboxPanel({
   activeTabId,
-  cloneSelectedRequest = ()=>{},
+  cloneSelectedRequest = () => {},
+  connector,
+  openLink,
   request,
   selectTab,
   sourceMapService,
-  openLink,
 }) {
   if (!request) {
     return null;
@@ -90,7 +91,7 @@ function TabboxPanel({
         id: PANELS.STACK_TRACE,
         title: STACK_TRACE_TITLE,
       },
-        StackTracePanel({ request, sourceMapService, openLink }),
+        StackTracePanel({ request, sourceMapService, openLink, connector }),
       ),
       request.securityState && request.securityState !== "insecure" &&
       TabPanel({
@@ -108,11 +109,11 @@ TabboxPanel.displayName = "TabboxPanel";
 TabboxPanel.propTypes = {
   activeTabId: PropTypes.string,
   cloneSelectedRequest: PropTypes.func,
+  connector: PropTypes.object.isRequired,
+  openLink: PropTypes.func,
   request: PropTypes.object,
   selectTab: PropTypes.func.isRequired,
-  // Service to enable the source map feature.
   sourceMapService: PropTypes.object,
-  openLink: PropTypes.func,
 };
 
 module.exports = connect()(TabboxPanel);
diff --git a/devtools/client/netmonitor/src/components/toolbar.js b/devtools/client/netmonitor/src/components/toolbar.js
index 68995ba84c78..255947e8f9b3 100644
--- a/devtools/client/netmonitor/src/components/toolbar.js
+++ b/devtools/client/netmonitor/src/components/toolbar.js
@@ -16,6 +16,7 @@ const Actions = require("../actions/index");
 const { FILTER_SEARCH_DELAY, FILTER_TAGS } = require("../constants");
 const {
   getDisplayedRequestsSummary,
+  getRecordingState,
   getRequestFilterTypes,
   getTypeFilteredRequests,
   isNetworkDetailsToggleButtonDisabled,
@@ -29,12 +30,15 @@ const SearchBox = createFactory(require("devtools/client/shared/components/Searc
 
 const { button, div, input, label, span } = DOM;
 
-const COLLPASE_DETAILS_PANE = L10N.getStr("collapseDetailsPane");
+// Localization
+const COLLAPSE_DETAILS_PANE = L10N.getStr("collapseDetailsPane");
 const EXPAND_DETAILS_PANE = L10N.getStr("expandDetailsPane");
 const SEARCH_KEY_SHORTCUT = L10N.getStr("netmonitor.toolbar.filterFreetext.key");
 const SEARCH_PLACE_HOLDER = L10N.getStr("netmonitor.toolbar.filterFreetext.label");
 const TOOLBAR_CLEAR = L10N.getStr("netmonitor.toolbar.clear");
+const TOOLBAR_TOGGLE_RECORDING = L10N.getStr("netmonitor.toolbar.toggleRecording");
 
+// Preferences
 const DEVTOOLS_DISABLE_CACHE_PREF = "devtools.cache.disabled";
 const DEVTOOLS_ENABLE_PERSISTENT_LOG_PREF = "devtools.netmonitor.persistlog";
 const TOOLBAR_FILTER_LABELS = FILTER_TAGS.concat("all").reduce((o, tag) =>
@@ -46,14 +50,18 @@ const ENABLE_PERSISTENT_LOGS_LABEL =
 const DISABLE_CACHE_TOOLTIP = L10N.getStr("netmonitor.toolbar.disableCache.tooltip");
 const DISABLE_CACHE_LABEL = L10N.getStr("netmonitor.toolbar.disableCache.label");
 
-/*
- * Network monitor toolbar component
+/**
+ * Network monitor toolbar component.
+ *
  * Toolbar contains a set of useful tools to control network requests
+ * as well as set of filters for filtering the content.
  */
 const Toolbar = createClass({
   displayName: "Toolbar",
 
   propTypes: {
+    toggleRecording: PropTypes.func.isRequired,
+    recording: PropTypes.bool.isRequired,
     clearRequests: PropTypes.func.isRequired,
     requestFilterTypes: PropTypes.array.isRequired,
     setRequestFilterText: PropTypes.func.isRequired,
@@ -70,8 +78,40 @@ const Toolbar = createClass({
     filteredRequests: PropTypes.object.isRequired,
   },
 
+  componentDidMount() {
+    Services.prefs.addObserver(DEVTOOLS_ENABLE_PERSISTENT_LOG_PREF,
+                               this.updatePersistentLogsEnabled);
+    Services.prefs.addObserver(DEVTOOLS_DISABLE_CACHE_PREF,
+                               this.updateBrowserCacheDisabled);
+  },
+
+  componentWillUnmount() {
+    Services.prefs.removeObserver(DEVTOOLS_ENABLE_PERSISTENT_LOG_PREF,
+                                  this.updatePersistentLogsEnabled);
+    Services.prefs.removeObserver(DEVTOOLS_DISABLE_CACHE_PREF,
+                                  this.updateBrowserCacheDisabled);
+  },
+
+  toggleRequestFilterType(evt) {
+    if (evt.type === "keydown" && (evt.key !== "" || evt.key !== "Enter")) {
+      return;
+    }
+    this.props.toggleRequestFilterType(evt.target.dataset.key);
+  },
+
+  updatePersistentLogsEnabled() {
+    this.props.enablePersistentLogs(
+      Services.prefs.getBoolPref(DEVTOOLS_ENABLE_PERSISTENT_LOG_PREF));
+  },
+
+  updateBrowserCacheDisabled() {
+    this.props.disableBrowserCache(
+      Services.prefs.getBoolPref(DEVTOOLS_DISABLE_CACHE_PREF));
+  },
+
   render() {
     let {
+      toggleRecording,
       clearRequests,
       requestFilterTypes,
       setRequestFilterText,
@@ -83,16 +123,19 @@ const Toolbar = createClass({
       toggleBrowserCache,
       browserCacheDisabled,
       filteredRequests,
+      recording,
     } = this.props;
 
     let toggleButtonClassName = [
       "network-details-panel-toggle",
       "devtools-button",
     ];
+
     if (!networkDetailsOpen) {
       toggleButtonClassName.push("pane-collapsed");
     }
 
+    // Render list of filter-buttons.
     let buttons = requestFilterTypes.map(([type, checked]) => {
       let classList = ["devtools-button", `requests-list-filter-${type}-button`];
       checked && classList.push("checked");
@@ -111,9 +154,23 @@ const Toolbar = createClass({
       );
     });
 
+    // Calculate class-list for toggle recording button. The button
+    // has two states: pause/play.
+    let toggleButtonClassList = [
+      "devtools-button",
+      "requests-list-pause-button",
+      recording ? "devtools-pause-icon" : "devtools-play-icon",
+    ];
+
+    // Render the entire toolbar.
     return (
       span({ className: "devtools-toolbar devtools-toolbar-container" },
         span({ className: "devtools-toolbar-group" },
+          button({
+            className: toggleButtonClassList.join(" "),
+            title: TOOLBAR_TOGGLE_RECORDING,
+            onClick: toggleRecording,
+          }),
           button({
             className: "devtools-button devtools-clear-icon requests-list-clear-button",
             title: TOOLBAR_CLEAR,
@@ -161,7 +218,7 @@ const Toolbar = createClass({
           }),
           button({
             className: toggleButtonClassName.join(" "),
-            title: networkDetailsOpen ? COLLPASE_DETAILS_PANE : EXPAND_DETAILS_PANE,
+            title: networkDetailsOpen ? COLLAPSE_DETAILS_PANE : EXPAND_DETAILS_PANE,
             disabled: networkDetailsToggleDisabled,
             tabIndex: "0",
             onClick: toggleNetworkDetails,
@@ -170,37 +227,6 @@ const Toolbar = createClass({
       )
     );
   },
-
-  componentDidMount() {
-    Services.prefs.addObserver(DEVTOOLS_ENABLE_PERSISTENT_LOG_PREF,
-                               this.updatePersistentLogsEnabled);
-    Services.prefs.addObserver(DEVTOOLS_DISABLE_CACHE_PREF,
-                               this.updateBrowserCacheDisabled);
-  },
-
-  componentWillUnmount() {
-    Services.prefs.removeObserver(DEVTOOLS_ENABLE_PERSISTENT_LOG_PREF,
-                                  this.updatePersistentLogsEnabled);
-    Services.prefs.removeObserver(DEVTOOLS_DISABLE_CACHE_PREF,
-                                  this.updateBrowserCacheDisabled);
-  },
-
-  toggleRequestFilterType(evt) {
-    if (evt.type === "keydown" && (evt.key !== "" || evt.key !== "Enter")) {
-      return;
-    }
-    this.props.toggleRequestFilterType(evt.target.dataset.key);
-  },
-
-  updatePersistentLogsEnabled() {
-    this.props.enablePersistentLogs(
-      Services.prefs.getBoolPref(DEVTOOLS_ENABLE_PERSISTENT_LOG_PREF));
-  },
-
-  updateBrowserCacheDisabled() {
-    this.props.disableBrowserCache(
-                        Services.prefs.getBoolPref(DEVTOOLS_DISABLE_CACHE_PREF));
-  }
 });
 
 module.exports = connect(
@@ -209,18 +235,20 @@ module.exports = connect(
     networkDetailsOpen: state.ui.networkDetailsOpen,
     persistentLogsEnabled: state.ui.persistentLogsEnabled,
     browserCacheDisabled: state.ui.browserCacheDisabled,
+    recording: getRecordingState(state),
     requestFilterTypes: getRequestFilterTypes(state),
     filteredRequests: getTypeFilteredRequests(state),
     summary: getDisplayedRequestsSummary(state),
   }),
   (dispatch) => ({
     clearRequests: () => dispatch(Actions.clearRequests()),
-    setRequestFilterText: (text) => dispatch(Actions.setRequestFilterText(text)),
-    toggleRequestFilterType: (type) => dispatch(Actions.toggleRequestFilterType(type)),
-    toggleNetworkDetails: () => dispatch(Actions.toggleNetworkDetails()),
-    enablePersistentLogs: (enabled) => dispatch(Actions.enablePersistentLogs(enabled)),
-    togglePersistentLogs: () => dispatch(Actions.togglePersistentLogs()),
     disableBrowserCache: (disabled) => dispatch(Actions.disableBrowserCache(disabled)),
+    enablePersistentLogs: (enabled) => dispatch(Actions.enablePersistentLogs(enabled)),
+    setRequestFilterText: (text) => dispatch(Actions.setRequestFilterText(text)),
     toggleBrowserCache: () => dispatch(Actions.toggleBrowserCache()),
+    toggleNetworkDetails: () => dispatch(Actions.toggleNetworkDetails()),
+    toggleRecording: () => dispatch(Actions.toggleRecording()),
+    togglePersistentLogs: () => dispatch(Actions.togglePersistentLogs()),
+    toggleRequestFilterType: (type) => dispatch(Actions.toggleRequestFilterType(type)),
   }),
 )(Toolbar);
diff --git a/devtools/client/netmonitor/src/connector/chrome-connector.js b/devtools/client/netmonitor/src/connector/chrome-connector.js
index 295f84fb2b62..ce42303d1a64 100644
--- a/devtools/client/netmonitor/src/connector/chrome-connector.js
+++ b/devtools/client/netmonitor/src/connector/chrome-connector.js
@@ -35,6 +35,14 @@ class ChromeConnector {
     this.connector.disconnect();
   }
 
+  pause() {
+    this.disconnect();
+  }
+
+  resume() {
+    this.setup();
+  }
+
   /**
    * currently all events are about "navigation" is not support on CDP
    */
diff --git a/devtools/client/netmonitor/src/connector/firefox-connector.js b/devtools/client/netmonitor/src/connector/firefox-connector.js
index f3ede8330265..76231e89aaae 100644
--- a/devtools/client/netmonitor/src/connector/firefox-connector.js
+++ b/devtools/client/netmonitor/src/connector/firefox-connector.js
@@ -7,7 +7,6 @@
 const Services = require("Services");
 const { TimelineFront } = require("devtools/shared/fronts/timeline");
 const { ACTIVITY_TYPE, EVENTS } = require("../constants");
-const { getDisplayedRequestById } = require("../selectors/index");
 const FirefoxDataProvider = require("./firefox-data-provider");
 
 class FirefoxConnector {
@@ -21,7 +20,6 @@ class FirefoxConnector {
     this.sendHTTPRequest = this.sendHTTPRequest.bind(this);
     this.setPreferences = this.setPreferences.bind(this);
     this.triggerActivity = this.triggerActivity.bind(this);
-    this.inspectRequest = this.inspectRequest.bind(this);
     this.getTabTarget = this.getTabTarget.bind(this);
     this.viewSourceInDebugger = this.viewSourceInDebugger.bind(this);
 
@@ -43,12 +41,7 @@ class FirefoxConnector {
       actions: this.actions,
     });
 
-    this.tabTarget.on("will-navigate", this.willNavigate);
-    this.tabTarget.on("close", this.disconnect);
-    this.webConsoleClient.on("networkEvent",
-      this.dataProvider.onNetworkEvent);
-    this.webConsoleClient.on("networkEventUpdate",
-      this.dataProvider.onNetworkEventUpdate);
+    this.addListeners();
 
     // Don't start up waiting for timeline markers if the server isn't
     // recent enough to emit the markers we're interested in.
@@ -71,16 +64,38 @@ class FirefoxConnector {
       await this.timelineFront.destroy();
     }
 
-    this.tabTarget.off("will-navigate");
-    this.tabTarget.off("close");
+    this.removeListeners();
+
     this.tabTarget = null;
-    this.webConsoleClient.off("networkEvent");
-    this.webConsoleClient.off("networkEventUpdate");
     this.webConsoleClient = null;
     this.timelineFront = null;
     this.dataProvider = null;
   }
 
+  pause() {
+    this.removeListeners();
+  }
+
+  resume() {
+    this.addListeners();
+  }
+
+  addListeners() {
+    this.tabTarget.on("will-navigate", this.willNavigate);
+    this.tabTarget.on("close", this.disconnect);
+    this.webConsoleClient.on("networkEvent",
+      this.dataProvider.onNetworkEvent);
+    this.webConsoleClient.on("networkEventUpdate",
+      this.dataProvider.onNetworkEventUpdate);
+  }
+
+  removeListeners() {
+    this.tabTarget.off("will-navigate");
+    this.tabTarget.off("close");
+    this.webConsoleClient.off("networkEvent");
+    this.webConsoleClient.off("networkEventUpdate");
+  }
+
   willNavigate() {
     if (!Services.prefs.getBoolPref("devtools.netmonitor.persistlog")) {
       this.actions.batchReset();
@@ -214,42 +229,6 @@ class FirefoxConnector {
     return Promise.reject(new Error("Invalid activity type"));
   }
 
-  /**
-   * Selects the specified request in the waterfall and opens the details view.
-   *
-   * @param {string} requestId The actor ID of the request to inspect.
-   * @return {object} A promise resolved once the task finishes.
-   */
-  inspectRequest(requestId) {
-    // Look for the request in the existing ones or wait for it to appear, if
-    // the network monitor is still loading.
-    return new Promise((resolve) => {
-      let request = null;
-      let inspector = () => {
-        request = getDisplayedRequestById(this.getState(), requestId);
-        if (!request) {
-          // Reset filters so that the request is visible.
-          this.actions.toggleRequestFilterType("all");
-          request = getDisplayedRequestById(this.getState(), requestId);
-        }
-
-        // If the request was found, select it. Otherwise this function will be
-        // called again once new requests arrive.
-        if (request) {
-          window.off(EVENTS.REQUEST_ADDED, inspector);
-          this.actions.selectRequest(request.id);
-          resolve();
-        }
-      };
-
-      inspector();
-
-      if (!request) {
-        window.on(EVENTS.REQUEST_ADDED, inspector);
-      }
-    });
-  }
-
   /**
    * Fetches the network information packet from actor server
    *
diff --git a/devtools/client/netmonitor/src/connector/firefox-data-provider.js b/devtools/client/netmonitor/src/connector/firefox-data-provider.js
index b47c4a61ad3a..b1b09843e509 100644
--- a/devtools/client/netmonitor/src/connector/firefox-data-provider.js
+++ b/devtools/client/netmonitor/src/connector/firefox-data-provider.js
@@ -428,6 +428,8 @@ class FirefoxDataProvider {
           });
         break;
     }
+
+    emit(EVENTS.NETWORK_EVENT_UPDATED, actor);
   }
 
   /**
diff --git a/devtools/client/netmonitor/src/connector/index.js b/devtools/client/netmonitor/src/connector/index.js
index eb43ca1617ee..7ff45f50aac3 100644
--- a/devtools/client/netmonitor/src/connector/index.js
+++ b/devtools/client/netmonitor/src/connector/index.js
@@ -3,83 +3,101 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
-let connector = {};
 
-function onConnect(connection, actions, getState) {
-  if (!connection || !connection.tab) {
-    return;
+/**
+ * Generic connector wrapper object that is responsible for
+ * instantiating specific connector implementation according
+ * to the client type.
+ */
+class Connector {
+  constructor() {
+    this.connector = null;
+
+    // Bind public API
+    this.connect = this.connect.bind(this);
+    this.disconnect = this.disconnect.bind(this);
+    this.connectChrome = this.connectChrome.bind(this);
+    this.connectFirefox = this.connectFirefox.bind(this);
+    this.getLongString = this.getLongString.bind(this);
+    this.getNetworkRequest = this.getNetworkRequest.bind(this);
+    this.getTabTarget = this.getTabTarget.bind(this);
+    this.sendHTTPRequest = this.sendHTTPRequest.bind(this);
+    this.setPreferences = this.setPreferences.bind(this);
+    this.triggerActivity = this.triggerActivity.bind(this);
+    this.viewSourceInDebugger = this.viewSourceInDebugger.bind(this);
   }
 
-  let { clientType } = connection.tab;
-  switch (clientType) {
-    case "chrome":
-      onChromeConnect(connection, actions, getState);
-      break;
-    case "firefox":
-      onFirefoxConnect(connection, actions, getState);
-      break;
-    default:
-      throw Error(`Unknown client type - ${clientType}`);
+  // Connect/Disconnect API
+
+  connect(connection, actions, getState) {
+    if (!connection || !connection.tab) {
+      return;
+    }
+
+    let { clientType } = connection.tab;
+    switch (clientType) {
+      case "chrome":
+        this.connectChrome(connection, actions, getState);
+        break;
+      case "firefox":
+        this.connectFirefox(connection, actions, getState);
+        break;
+      default:
+        throw Error(`Unknown client type - ${clientType}`);
+    }
+  }
+
+  disconnect() {
+    this.connector && this.connector.disconnect();
+  }
+
+  connectChrome(connection, actions, getState) {
+    this.connector = require("./chrome-connector");
+    this.connector.connect(connection, actions, getState);
+  }
+
+  connectFirefox(connection, actions, getState) {
+    this.connector = require("./firefox-connector");
+    this.connector.connect(connection, actions, getState);
+  }
+
+  pause() {
+    this.connector.pause();
+  }
+
+  resume() {
+    this.connector.resume();
+  }
+
+  // Public API
+
+  getLongString() {
+    return this.connector.getLongString(...arguments);
+  }
+
+  getNetworkRequest() {
+    return this.connector.getNetworkRequest(...arguments);
+  }
+
+  getTabTarget() {
+    return this.connector.getTabTarget();
+  }
+
+  sendHTTPRequest() {
+    return this.connector.sendHTTPRequest(...arguments);
+  }
+
+  setPreferences() {
+    return this.connector.setPreferences(...arguments);
+  }
+
+  triggerActivity() {
+    return this.connector.triggerActivity(...arguments);
+  }
+
+  viewSourceInDebugger() {
+    return this.connector.viewSourceInDebugger(...arguments);
   }
 }
 
-function onDisconnect() {
-  connector && connector.disconnect();
-}
-
-function onChromeConnect(connection, actions, getState) {
-  connector = require("./chrome-connector");
-  connector.connect(connection, actions, getState);
-}
-
-function onFirefoxConnect(connection, actions, getState) {
-  connector = require("./firefox-connector");
-  connector.connect(connection, actions, getState);
-}
-
-function inspectRequest() {
-  return connector.inspectRequest(...arguments);
-}
-
-function getLongString() {
-  return connector.getLongString(...arguments);
-}
-
-function getNetworkRequest() {
-  return connector.getNetworkRequest(...arguments);
-}
-
-function getTabTarget() {
-  return connector.getTabTarget();
-}
-
-function sendHTTPRequest() {
-  return connector.sendHTTPRequest(...arguments);
-}
-
-function setPreferences() {
-  return connector.setPreferences(...arguments);
-}
-
-function triggerActivity() {
-  return connector.triggerActivity(...arguments);
-}
-
-function viewSourceInDebugger() {
-  return connector.viewSourceInDebugger(...arguments);
-}
-
-module.exports = {
-  onConnect,
-  onChromeConnect,
-  onFirefoxConnect,
-  onDisconnect,
-  getLongString,
-  getNetworkRequest,
-  getTabTarget,
-  inspectRequest,
-  sendHTTPRequest,
-  setPreferences,
-  triggerActivity,
-  viewSourceInDebugger,
-};
+module.exports.Connector = Connector;
diff --git a/devtools/client/netmonitor/src/constants.js b/devtools/client/netmonitor/src/constants.js
index 9600374c4ec8..40a2db674375 100644
--- a/devtools/client/netmonitor/src/constants.js
+++ b/devtools/client/netmonitor/src/constants.js
@@ -25,6 +25,7 @@ const actionTypes = {
   SET_REQUEST_FILTER_TEXT: "SET_REQUEST_FILTER_TEXT",
   SORT_BY: "SORT_BY",
   TOGGLE_COLUMN: "TOGGLE_COLUMN",
+  TOGGLE_RECORDING: "TOGGLE_RECORDING",
   TOGGLE_REQUEST_FILTER_TYPE: "TOGGLE_REQUEST_FILTER_TYPE",
   UPDATE_REQUEST: "UPDATE_REQUEST",
   WATERFALL_RESIZE: "WATERFALL_RESIZE",
@@ -53,6 +54,7 @@ const EVENTS = {
   // See https://developer.mozilla.org/docs/Tools/Web_Console/remoting for
   // more information about what each packet is supposed to deliver.
   NETWORK_EVENT: "NetMonitor:NetworkEvent",
+  NETWORK_EVENT_UPDATED: "NetMonitor:NetworkEventUpdated",
   TIMELINE_EVENT: "NetMonitor:TimelineEvent",
 
   // When a network event is added to the view
diff --git a/devtools/client/netmonitor/src/har/test/browser_net_har_copy_all_as_har.js b/devtools/client/netmonitor/src/har/test/browser_net_har_copy_all_as_har.js
index d5b941d90795..1dd55fb4dcb5 100644
--- a/devtools/client/netmonitor/src/har/test/browser_net_har_copy_all_as_har.js
+++ b/devtools/client/netmonitor/src/har/test/browser_net_har_copy_all_as_har.js
@@ -15,10 +15,11 @@ add_task(function* () {
 
   info("Starting test... ");
 
-  let { store, windowRequire } = monitor.panelWin;
+  let { connector, store, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
   let RequestListContextMenu = windowRequire(
     "devtools/client/netmonitor/src/request-list-context-menu");
+  let { getLongString, getTabTarget } = connector;
 
   store.dispatch(Actions.batchEnable(false));
 
@@ -26,7 +27,8 @@ add_task(function* () {
   tab.linkedBrowser.reload();
   yield wait;
 
-  let contextMenu = new RequestListContextMenu({});
+  let contextMenu = new RequestListContextMenu({ getTabTarget, getLongString });
+
   yield contextMenu.copyAllAsHar();
 
   let jsonString = SpecialPowers.getClipboardData("text/unicode");
diff --git a/devtools/client/netmonitor/src/har/test/browser_net_har_post_data.js b/devtools/client/netmonitor/src/har/test/browser_net_har_post_data.js
index 0082d3e5471c..bbcc2925e1cf 100644
--- a/devtools/client/netmonitor/src/har/test/browser_net_har_post_data.js
+++ b/devtools/client/netmonitor/src/har/test/browser_net_har_post_data.js
@@ -12,10 +12,11 @@ add_task(function* () {
 
   info("Starting test... ");
 
-  let { store, windowRequire } = monitor.panelWin;
+  let { connector, store, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
   let RequestListContextMenu = windowRequire(
     "devtools/client/netmonitor/src/request-list-context-menu");
+  let { getLongString, getTabTarget } = connector;
 
   store.dispatch(Actions.batchEnable(false));
 
@@ -27,7 +28,7 @@ add_task(function* () {
   yield wait;
 
   // Copy HAR into the clipboard (asynchronous).
-  let contextMenu = new RequestListContextMenu({});
+  let contextMenu = new RequestListContextMenu({ getTabTarget, getLongString });
   let jsonString = yield contextMenu.copyAllAsHar();
   let har = JSON.parse(jsonString);
 
diff --git a/devtools/client/netmonitor/src/har/test/browser_net_har_post_data_on_get.js b/devtools/client/netmonitor/src/har/test/browser_net_har_post_data_on_get.js
index 74ed37f048b1..a8f2bc4e4786 100644
--- a/devtools/client/netmonitor/src/har/test/browser_net_har_post_data_on_get.js
+++ b/devtools/client/netmonitor/src/har/test/browser_net_har_post_data_on_get.js
@@ -12,10 +12,11 @@ add_task(function* () {
 
   info("Starting test... ");
 
-  let { store, windowRequire } = monitor.panelWin;
+  let { connector, store, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
   let RequestListContextMenu = windowRequire(
     "devtools/client/netmonitor/src/request-list-context-menu");
+  let { getLongString, getTabTarget } = connector;
 
   store.dispatch(Actions.batchEnable(false));
 
@@ -27,7 +28,7 @@ add_task(function* () {
   yield wait;
 
   // Copy HAR into the clipboard (asynchronous).
-  let contextMenu = new RequestListContextMenu({});
+  let contextMenu = new RequestListContextMenu({ getTabTarget, getLongString });
   let jsonString = yield contextMenu.copyAllAsHar();
   let har = JSON.parse(jsonString);
 
diff --git a/devtools/client/netmonitor/src/har/test/browser_net_har_throttle_upload.js b/devtools/client/netmonitor/src/har/test/browser_net_har_throttle_upload.js
index ff486511b25c..a689a7a68ac3 100644
--- a/devtools/client/netmonitor/src/har/test/browser_net_har_throttle_upload.js
+++ b/devtools/client/netmonitor/src/har/test/browser_net_har_throttle_upload.js
@@ -16,12 +16,11 @@ function* throttleUploadTest(actuallyThrottle) {
 
   info("Starting test... (actuallyThrottle = " + actuallyThrottle + ")");
 
-  let { store, windowRequire } = monitor.panelWin;
+  let { connector, store, windowRequire } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
-  let { setPreferences } =
-    windowRequire("devtools/client/netmonitor/src/connector/index");
   let RequestListContextMenu = windowRequire(
     "devtools/client/netmonitor/src/request-list-context-menu");
+  let { getLongString, getTabTarget, setPreferences } = connector;
 
   store.dispatch(Actions.batchEnable(false));
 
@@ -54,7 +53,7 @@ function* throttleUploadTest(actuallyThrottle) {
   yield wait;
 
   // Copy HAR into the clipboard (asynchronous).
-  let contextMenu = new RequestListContextMenu({});
+  let contextMenu = new RequestListContextMenu({ getTabTarget, getLongString });
   let jsonString = yield contextMenu.copyAllAsHar();
   let har = JSON.parse(jsonString);
 
diff --git a/devtools/client/netmonitor/src/middleware/moz.build b/devtools/client/netmonitor/src/middleware/moz.build
index cd76bc848eef..f70b43cede4e 100644
--- a/devtools/client/netmonitor/src/middleware/moz.build
+++ b/devtools/client/netmonitor/src/middleware/moz.build
@@ -5,5 +5,6 @@
 DevToolsModules(
     'batching.js',
     'prefs.js',
+    'recording.js',
     'thunk.js',
 )
diff --git a/devtools/client/netmonitor/src/middleware/recording.js b/devtools/client/netmonitor/src/middleware/recording.js
new file mode 100644
index 000000000000..a146011d5994
--- /dev/null
+++ b/devtools/client/netmonitor/src/middleware/recording.js
@@ -0,0 +1,41 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const {
+  TOGGLE_RECORDING,
+} = require("../constants");
+
+const {
+  getRecordingState,
+} = require("../selectors/index");
+
+/**
+ * Start/stop HTTP traffic recording.
+ *
+ * The UI state of the toolbar toggle button is stored in UI
+ * reducer and the backend connection is managed here in the
+ * middleware.
+ */
+function recordingMiddleware(connector) {
+  return store => next => action => {
+    const res = next(action);
+
+    // Pause/resume HTTP monitoring according to
+    // the user action.
+    if (action.type === TOGGLE_RECORDING) {
+      let recording = getRecordingState(store.getState());
+      if (recording) {
+        connector.resume();
+      } else {
+        connector.pause();
+      }
+    }
+
+    return res;
+  };
+}
+
+module.exports = recordingMiddleware;
diff --git a/devtools/client/netmonitor/src/reducers/requests.js b/devtools/client/netmonitor/src/reducers/requests.js
index a4cddfb451be..06046e313094 100644
--- a/devtools/client/netmonitor/src/reducers/requests.js
+++ b/devtools/client/netmonitor/src/reducers/requests.js
@@ -14,6 +14,7 @@ const {
   REMOVE_SELECTED_CUSTOM_REQUEST,
   SELECT_REQUEST,
   SEND_CUSTOM_REQUEST,
+  TOGGLE_RECORDING,
   UPDATE_REQUEST,
   UPDATE_PROPS,
 } = require("../constants");
@@ -68,6 +69,8 @@ const Requests = I.Record({
   // Auxiliary fields to hold requests stats
   firstStartedMillis: +Infinity,
   lastEndedMillis: -Infinity,
+  // Recording state
+  recording: true,
 });
 
 /**
@@ -120,6 +123,64 @@ function requestsReducer(state = new Requests(), action) {
         }
       });
     }
+    case CLEAR_REQUESTS: {
+      return new Requests({
+        recording: state.recording
+      });
+    }
+    case CLONE_SELECTED_REQUEST: {
+      let { requests, selectedId } = state;
+
+      if (!selectedId) {
+        return state;
+      }
+
+      let clonedRequest = requests.get(selectedId);
+      if (!clonedRequest) {
+        return state;
+      }
+
+      let newRequest = new Request({
+        id: clonedRequest.id + "-clone",
+        method: clonedRequest.method,
+        url: clonedRequest.url,
+        urlDetails: clonedRequest.urlDetails,
+        requestHeaders: clonedRequest.requestHeaders,
+        requestPostData: clonedRequest.requestPostData,
+        isCustom: true
+      });
+
+      return state.withMutations(st => {
+        st.requests = requests.set(newRequest.id, newRequest);
+        st.selectedId = newRequest.id;
+      });
+    }
+    case OPEN_NETWORK_DETAILS: {
+      if (!action.open) {
+        return state.set("selectedId", null);
+      }
+
+      if (!state.selectedId && !state.requests.isEmpty()) {
+        return state.set("selectedId", state.requests.first().id);
+      }
+
+      return state;
+    }
+    case REMOVE_SELECTED_CUSTOM_REQUEST: {
+      return closeCustomRequest(state);
+    }
+    case SELECT_REQUEST: {
+      return state.set("selectedId", action.id);
+    }
+    case SEND_CUSTOM_REQUEST: {
+      // When a new request with a given id is added in future, select it immediately.
+      // where we know in advance the ID of the request, at a time when it
+      // wasn't sent yet.
+      return closeCustomRequest(state.set("preselectedId", action.id));
+    }
+    case TOGGLE_RECORDING: {
+      return state.set("recording", !state.recording);
+    }
     case UPDATE_REQUEST: {
       let { requests, lastEndedMillis } = state;
 
@@ -160,59 +221,6 @@ function requestsReducer(state = new Requests(), action) {
         st.lastEndedMillis = lastEndedMillis;
       });
     }
-    case CLEAR_REQUESTS: {
-      return new Requests();
-    }
-    case SELECT_REQUEST: {
-      return state.set("selectedId", action.id);
-    }
-    case CLONE_SELECTED_REQUEST: {
-      let { requests, selectedId } = state;
-
-      if (!selectedId) {
-        return state;
-      }
-
-      let clonedRequest = requests.get(selectedId);
-      if (!clonedRequest) {
-        return state;
-      }
-
-      let newRequest = new Request({
-        id: clonedRequest.id + "-clone",
-        method: clonedRequest.method,
-        url: clonedRequest.url,
-        urlDetails: clonedRequest.urlDetails,
-        requestHeaders: clonedRequest.requestHeaders,
-        requestPostData: clonedRequest.requestPostData,
-        isCustom: true
-      });
-
-      return state.withMutations(st => {
-        st.requests = requests.set(newRequest.id, newRequest);
-        st.selectedId = newRequest.id;
-      });
-    }
-    case REMOVE_SELECTED_CUSTOM_REQUEST: {
-      return closeCustomRequest(state);
-    }
-    case SEND_CUSTOM_REQUEST: {
-      // When a new request with a given id is added in future, select it immediately.
-      // where we know in advance the ID of the request, at a time when it
-      // wasn't sent yet.
-      return closeCustomRequest(state.set("preselectedId", action.id));
-    }
-    case OPEN_NETWORK_DETAILS: {
-      if (!action.open) {
-        return state.set("selectedId", null);
-      }
-
-      if (!state.selectedId && !state.requests.isEmpty()) {
-        return state.set("selectedId", state.requests.first().id);
-      }
-
-      return state;
-    }
 
     default:
       return state;
diff --git a/devtools/client/netmonitor/src/request-list-context-menu.js b/devtools/client/netmonitor/src/request-list-context-menu.js
index d1b2a3cfac89..de6eee992b86 100644
--- a/devtools/client/netmonitor/src/request-list-context-menu.js
+++ b/devtools/client/netmonitor/src/request-list-context-menu.js
@@ -10,10 +10,6 @@ const { gDevTools } = require("devtools/client/framework/devtools");
 const { saveAs } = require("devtools/client/shared/file-saver");
 const { copyString } = require("devtools/shared/platform/clipboard");
 const { HarExporter } = require("./har/har-exporter");
-const {
-  getLongString,
-  getTabTarget,
-} = require("./connector/index");
 const {
   getSelectedRequest,
   getSortedRequests,
@@ -28,9 +24,13 @@ const {
 
 function RequestListContextMenu({
   cloneSelectedRequest,
+  getLongString,
+  getTabTarget,
   openStatistics,
 }) {
   this.cloneSelectedRequest = cloneSelectedRequest;
+  this.getLongString = getLongString;
+  this.getTabTarget = getTabTarget;
   this.openStatistics = openStatistics;
 }
 
@@ -239,7 +239,7 @@ RequestListContextMenu.prototype = {
    * Opens selected item in the debugger
    */
   openInDebugger() {
-    let toolbox = gDevTools.getToolbox(getTabTarget());
+    let toolbox = gDevTools.getToolbox(this.getTabTarget());
     toolbox.viewSourceInDebugger(this.selectedRequest.url, 0);
   },
 
@@ -247,7 +247,7 @@ RequestListContextMenu.prototype = {
    * Opens selected item in the style editor
    */
   openInStyleEditor() {
-    let toolbox = gDevTools.getToolbox(getTabTarget());
+    let toolbox = gDevTools.getToolbox(this.getTabTarget());
     toolbox.viewSourceInStyleEditor(this.selectedRequest.url, 0);
   },
 
@@ -387,11 +387,11 @@ RequestListContextMenu.prototype = {
   },
 
   getDefaultHarOptions() {
-    let form = getTabTarget().form;
+    let form = this.getTabTarget().form;
     let title = form.title || form.url;
 
     return {
-      getString: getLongString,
+      getString: this.getLongString,
       items: this.sortedRequests,
       title: title
     };
diff --git a/devtools/client/netmonitor/src/request-list-tooltip.js b/devtools/client/netmonitor/src/request-list-tooltip.js
index e4feffa97905..e359aed78d2b 100644
--- a/devtools/client/netmonitor/src/request-list-tooltip.js
+++ b/devtools/client/netmonitor/src/request-list-tooltip.js
@@ -8,19 +8,18 @@ const {
   setImageTooltip,
   getImageDimensions,
 } = require("devtools/client/shared/widgets/tooltip/ImageTooltipHelper");
-const { getLongString } = require("./connector/index");
 const { formDataURI } = require("./utils/request-utils");
 
 const REQUESTS_TOOLTIP_IMAGE_MAX_DIM = 400; // px
 
-async function setTooltipImageContent(tooltip, itemEl, requestItem) {
+async function setTooltipImageContent(connector, tooltip, itemEl, requestItem) {
   let { mimeType, text, encoding } = requestItem.responseContent.content;
 
   if (!mimeType || !mimeType.includes("image/")) {
     return false;
   }
 
-  let string = await getLongString(text);
+  let string = await connector.getLongString(text);
   let src = formDataURI(mimeType, encoding, string);
   let maxDim = REQUESTS_TOOLTIP_IMAGE_MAX_DIM;
   let { naturalWidth, naturalHeight } = await getImageDimensions(tooltip.doc, src);
diff --git a/devtools/client/netmonitor/src/selectors/requests.js b/devtools/client/netmonitor/src/selectors/requests.js
index 880f8317a502..b7950ef029f1 100644
--- a/devtools/client/netmonitor/src/selectors/requests.js
+++ b/devtools/client/netmonitor/src/selectors/requests.js
@@ -127,10 +127,19 @@ function getDisplayedRequestById(state, id) {
   return getDisplayedRequests(state).find(r => r.id === id);
 }
 
+/**
+ * Returns the current recording boolean state (HTTP traffic is
+ * monitored or not monitored)
+ */
+function getRecordingState(state) {
+  return state.requests.recording;
+}
+
 module.exports = {
   getDisplayedRequestById,
   getDisplayedRequests,
   getDisplayedRequestsSummary,
+  getRecordingState,
   getRequestById,
   getSelectedRequest,
   getSortedRequests,
diff --git a/devtools/client/netmonitor/src/utils/create-store.js b/devtools/client/netmonitor/src/utils/create-store.js
index 05e76739a774..49fd73849522 100644
--- a/devtools/client/netmonitor/src/utils/create-store.js
+++ b/devtools/client/netmonitor/src/utils/create-store.js
@@ -6,9 +6,14 @@
 
 const Services = require("Services");
 const { applyMiddleware, createStore } = require("devtools/client/shared/vendor/redux");
+
+// Middleware
 const batching = require("../middleware/batching");
 const prefs = require("../middleware/prefs");
 const thunk = require("../middleware/thunk");
+const recording = require("../middleware/recording");
+
+// Reducers
 const rootReducer = require("../reducers/index");
 const { FilterTypes, Filters } = require("../reducers/filters");
 const { Requests } = require("../reducers/requests");
@@ -16,21 +21,40 @@ const { Sort } = require("../reducers/sort");
 const { TimingMarkers } = require("../reducers/timing-markers");
 const { UI, Columns } = require("../reducers/ui");
 
-function configureStore() {
-  const getPref = (pref) => {
-    try {
-      return JSON.parse(Services.prefs.getCharPref(pref));
-    } catch (_) {
-      return [];
-    }
+/**
+ * Configure state and middleware for the Network monitor tool.
+ */
+function configureStore(connector) {
+  // Prepare initial state.
+  const initialState = {
+    filters: new Filters({
+      requestFilterTypes: getFilterState()
+    }),
+    requests: new Requests(),
+    sort: new Sort(),
+    timingMarkers: new TimingMarkers(),
+    ui: new UI({
+      columns: getColumnState()
+    }),
   };
 
-  let activeFilters = {};
-  let filters = getPref("devtools.netmonitor.filters");
-  filters.forEach((filter) => {
-    activeFilters[filter] = true;
-  });
+  // Prepare middleware.
+  let middleware = applyMiddleware(
+    thunk,
+    prefs,
+    batching,
+    recording(connector)
+  );
 
+  return createStore(rootReducer, initialState, middleware);
+}
+
+// Helpers
+
+/**
+ * Get column state from preferences.
+ */
+function getColumnState() {
   let columns = new Columns();
   let visibleColumns = getPref("devtools.netmonitor.visibleColumns");
 
@@ -40,19 +64,27 @@ function configureStore() {
     });
   }
 
-  const initialState = {
-    filters: new Filters({
-      requestFilterTypes: new FilterTypes(activeFilters)
-    }),
-    requests: new Requests(),
-    sort: new Sort(),
-    timingMarkers: new TimingMarkers(),
-    ui: new UI({
-      columns,
-    }),
-  };
+  return columns;
+}
 
-  return createStore(rootReducer, initialState, applyMiddleware(thunk, prefs, batching));
+/**
+ * Get filter state from preferences.
+ */
+function getFilterState() {
+  let activeFilters = {};
+  let filters = getPref("devtools.netmonitor.filters");
+  filters.forEach((filter) => {
+    activeFilters[filter] = true;
+  });
+  return new FilterTypes(activeFilters);
+}
+
+function getPref(pref) {
+  try {
+    return JSON.parse(Services.prefs.getCharPref(pref));
+  } catch (_) {
+    return [];
+  }
 }
 
 exports.configureStore = configureStore;
diff --git a/devtools/client/netmonitor/test/browser.ini b/devtools/client/netmonitor/test/browser.ini
index 6804624d1809..17dfa87d4795 100644
--- a/devtools/client/netmonitor/test/browser.ini
+++ b/devtools/client/netmonitor/test/browser.ini
@@ -25,6 +25,7 @@ support-files =
   html_maps-test-page.html
   html_navigate-test-page.html
   html_params-test-page.html
+  html_pause-test-page.html
   html_post-data-test-page.html
   html_post-json-test-page.html
   html_post-raw-test-page.html
@@ -135,6 +136,7 @@ skip-if = (os == 'linux' && debug && bits == 32) # Bug 1303439
 [browser_net_open_request_in_tab.js]
 [browser_net_pane-collapse.js]
 [browser_net_pane-toggle.js]
+[browser_net_pause.js]
 [browser_net_params_sorted.js]
 [browser_net_persistent_logs.js]
 [browser_net_post-data-01.js]
diff --git a/devtools/client/netmonitor/test/browser_net_curl-utils.js b/devtools/client/netmonitor/test/browser_net_curl-utils.js
index 8dbbcc984a25..1312d5e5abb0 100644
--- a/devtools/client/netmonitor/test/browser_net_curl-utils.js
+++ b/devtools/client/netmonitor/test/browser_net_curl-utils.js
@@ -13,12 +13,12 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(CURL_UTILS_URL);
   info("Starting test... ");
 
-  let { store, windowRequire } = monitor.panelWin;
+  let { store, windowRequire, connector } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
   let {
     getSortedRequests,
   } = windowRequire("devtools/client/netmonitor/src/selectors/index");
-  let { getLongString } = windowRequire("devtools/client/netmonitor/src/connector/index");
+  let { getLongString } = connector;
 
   store.dispatch(Actions.batchEnable(false));
 
diff --git a/devtools/client/netmonitor/test/browser_net_icon-preview.js b/devtools/client/netmonitor/test/browser_net_icon-preview.js
index 8b19c6f6e424..48d2c6c3d482 100644
--- a/devtools/client/netmonitor/test/browser_net_icon-preview.js
+++ b/devtools/client/netmonitor/test/browser_net_icon-preview.js
@@ -12,10 +12,9 @@ add_task(function* () {
   const SELECTOR = ".requests-list-icon[src]";
   info("Starting test... ");
 
-  let { document, store, windowRequire } = monitor.panelWin;
+  let { document, store, windowRequire, connector } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
-  let { triggerActivity } =
-    windowRequire("devtools/client/netmonitor/src/connector/index");
+  let { triggerActivity } = connector;
   let { ACTIVITY_TYPE } = windowRequire("devtools/client/netmonitor/src/constants");
 
   store.dispatch(Actions.batchEnable(false));
diff --git a/devtools/client/netmonitor/test/browser_net_image-tooltip.js b/devtools/client/netmonitor/test/browser_net_image-tooltip.js
index 1cb79c275dc1..f250932e9bff 100644
--- a/devtools/client/netmonitor/test/browser_net_image-tooltip.js
+++ b/devtools/client/netmonitor/test/browser_net_image-tooltip.js
@@ -14,10 +14,9 @@ add_task(function* test() {
   const SELECTOR = ".requests-list-icon[src]";
   info("Starting test... ");
 
-  let { document, store, windowRequire } = monitor.panelWin;
+  let { document, store, windowRequire, connector } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
-  let { triggerActivity } =
-    windowRequire("devtools/client/netmonitor/src/connector/index");
+  let { triggerActivity } = connector;
   let { ACTIVITY_TYPE } = windowRequire("devtools/client/netmonitor/src/constants");
   let toolboxDoc = monitor.panelWin.parent.document;
 
diff --git a/devtools/client/netmonitor/test/browser_net_pause.js b/devtools/client/netmonitor/test/browser_net_pause.js
new file mode 100644
index 000000000000..9670e76dbaf8
--- /dev/null
+++ b/devtools/client/netmonitor/test/browser_net_pause.js
@@ -0,0 +1,90 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * Tests if the pause/resume button works.
+ */
+add_task(function* () {
+  let { tab, monitor } = yield initNetMonitor(PAUSE_URL);
+  info("Starting test... ");
+
+  let { document, store, windowRequire, connector } = monitor.panelWin;
+  let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
+  let pauseButton = document.querySelector(".requests-list-pause-button");
+
+  store.dispatch(Actions.batchEnable(false));
+
+  // Make sure we start in a sane state.
+  assertRequestCount(store, 0);
+
+  // Load one request and assert it shows up in the list.
+  yield performRequestAndWait(tab, monitor);
+  assertRequestCount(store, 1);
+
+  let noRequest = true;
+  monitor.panelWin.once(EVENTS.NETWORK_EVENT, () => {
+    noRequest = false;
+  });
+
+  monitor.panelWin.once(EVENTS.NETWORK_EVENT_UPDATED, () => {
+    noRequest = false;
+  });
+
+  // Click pause, load second request and make sure they don't show up.
+  EventUtils.sendMouseEvent({ type: "click" }, pauseButton);
+  yield performPausedRequest(connector, tab, monitor);
+  ok(noRequest, "There should be no activity when paused.");
+  assertRequestCount(store, 1);
+
+  // Click pause again to resume monitoring. Load a third request
+  // and make sure they will show up.
+  EventUtils.sendMouseEvent({ type: "click" }, pauseButton);
+  yield performRequestAndWait(tab, monitor);
+  assertRequestCount(store, 2);
+
+  return teardown(monitor);
+});
+
+/**
+ * Asserts the number of requests in the network monitor.
+ */
+function assertRequestCount(store, count) {
+  is(store.getState().requests.requests.size, count,
+    "There should be correct number of requests");
+}
+
+/**
+ * Execute simple GET request and wait till it's done.
+ */
+function* performRequestAndWait(tab, monitor) {
+  let wait = waitForNetworkEvents(monitor, 1);
+  yield ContentTask.spawn(tab.linkedBrowser, SIMPLE_SJS, function* (url) {
+    yield content.wrappedJSObject.performRequests(url);
+  });
+  yield wait;
+}
+
+/**
+ * Execute simple GET request
+ */
+function* performPausedRequest(connector, tab, monitor) {
+  let wait = waitForWebConsoleNetworkEvent(connector);
+  yield ContentTask.spawn(tab.linkedBrowser, SIMPLE_SJS, function* (url) {
+    yield content.wrappedJSObject.performRequests(url);
+  });
+  yield wait;
+}
+
+/**
+ * Listen for events fired by the console client since the Firefox
+ * connector (data provider) is paused.
+ */
+function waitForWebConsoleNetworkEvent(connector) {
+  return new Promise(resolve => {
+    connector.connector.webConsoleClient.once("networkEvent", (type, networkInfo) => {
+      resolve();
+    });
+  });
+}
diff --git a/devtools/client/netmonitor/test/browser_net_resend.js b/devtools/client/netmonitor/test/browser_net_resend.js
index 581efcbf62ff..7998256bdee1 100644
--- a/devtools/client/netmonitor/test/browser_net_resend.js
+++ b/devtools/client/netmonitor/test/browser_net_resend.js
@@ -16,7 +16,7 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(POST_DATA_URL);
   info("Starting test... ");
 
-  let { document, store, windowRequire } = monitor.panelWin;
+  let { document, store, windowRequire, connector } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
   let {
     getSelectedRequest,
@@ -51,7 +51,7 @@ add_task(function* () {
 
   // send the new request
   wait = waitForNetworkEvents(monitor, 0, 1);
-  store.dispatch(Actions.sendCustomRequest());
+  store.dispatch(Actions.sendCustomRequest(connector));
   yield wait;
 
   let sentItem = getSelectedRequest(store.getState());
diff --git a/devtools/client/netmonitor/test/browser_net_resend_cors.js b/devtools/client/netmonitor/test/browser_net_resend_cors.js
index 1f0fc289ade0..6980df680f91 100644
--- a/devtools/client/netmonitor/test/browser_net_resend_cors.js
+++ b/devtools/client/netmonitor/test/browser_net_resend_cors.js
@@ -12,7 +12,7 @@ add_task(function* () {
   let { tab, monitor } = yield initNetMonitor(CORS_URL);
   info("Starting test... ");
 
-  let { store, windowRequire } = monitor.panelWin;
+  let { store, windowRequire, connector } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
   let {
     getSortedRequests,
@@ -49,7 +49,7 @@ add_task(function* () {
     store.dispatch(Actions.cloneSelectedRequest());
 
     info("Sending the cloned request (without change)");
-    store.dispatch(Actions.sendCustomRequest());
+    store.dispatch(Actions.sendCustomRequest(connector));
   });
 
   info("Waiting for both resent requests");
diff --git a/devtools/client/netmonitor/test/browser_net_resend_headers.js b/devtools/client/netmonitor/test/browser_net_resend_headers.js
index 8f599e2a0a0f..78f0e3fd6d67 100644
--- a/devtools/client/netmonitor/test/browser_net_resend_headers.js
+++ b/devtools/client/netmonitor/test/browser_net_resend_headers.js
@@ -11,10 +11,9 @@ add_task(function* () {
   let { monitor } = yield initNetMonitor(SIMPLE_SJS);
   info("Starting test... ");
 
-  let { store, windowRequire } = monitor.panelWin;
+  let { store, windowRequire, connector } = monitor.panelWin;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
-  let { sendHTTPRequest } =
-    windowRequire("devtools/client/netmonitor/src/connector/index");
+  let { sendHTTPRequest } = connector;
   let {
     getSortedRequests,
   } = windowRequire("devtools/client/netmonitor/src/selectors/index");
diff --git a/devtools/client/netmonitor/test/browser_net_statistics-01.js b/devtools/client/netmonitor/test/browser_net_statistics-01.js
index 54f00ea65103..17d95e30a30d 100644
--- a/devtools/client/netmonitor/test/browser_net_statistics-01.js
+++ b/devtools/client/netmonitor/test/browser_net_statistics-01.js
@@ -12,14 +12,14 @@ add_task(function* () {
   info("Starting test... ");
 
   let panel = monitor.panelWin;
-  let { document, store, windowRequire } = panel;
+  let { document, store, windowRequire, connector } = panel;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
 
   ok(document.querySelector(".monitor-panel"),
     "The current main panel is correct.");
 
   info("Displaying statistics panel");
-  store.dispatch(Actions.openStatistics(true));
+  store.dispatch(Actions.openStatistics(connector, true));
 
   ok(document.querySelector(".statistics-panel"),
     "The current main panel is correct.");
diff --git a/devtools/client/netmonitor/test/browser_net_statistics-02.js b/devtools/client/netmonitor/test/browser_net_statistics-02.js
index b9faa60a94eb..b8d731efb7eb 100644
--- a/devtools/client/netmonitor/test/browser_net_statistics-02.js
+++ b/devtools/client/netmonitor/test/browser_net_statistics-02.js
@@ -13,7 +13,7 @@ add_task(function* () {
   info("Starting test... ");
 
   let panel = monitor.panelWin;
-  let { document, store, windowRequire } = panel;
+  let { document, store, windowRequire, connector } = panel;
   let Actions = windowRequire("devtools/client/netmonitor/src/actions/index");
 
   EventUtils.sendMouseEvent({ type: "click" },
@@ -29,7 +29,7 @@ add_task(function* () {
   testFilterButtonsCustom(monitor, [0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1]);
   info("The correct filtering predicates are used before entering perf. analysis mode.");
 
-  store.dispatch(Actions.openStatistics(true));
+  store.dispatch(Actions.openStatistics(connector, true));
 
   ok(document.querySelector(".statistics-panel"),
     "The main panel is switched to the statistics panel.");
diff --git a/devtools/client/netmonitor/test/browser_net_throttle.js b/devtools/client/netmonitor/test/browser_net_throttle.js
index 8fbc73b94ada..dd06ad598208 100644
--- a/devtools/client/netmonitor/test/browser_net_throttle.js
+++ b/devtools/client/netmonitor/test/browser_net_throttle.js
@@ -14,11 +14,10 @@ function* throttleTest(actuallyThrottle) {
   requestLongerTimeout(2);
 
   let { monitor } = yield initNetMonitor(SIMPLE_URL);
-  let { store, windowRequire } = monitor.panelWin;
+  let { store, windowRequire, connector } = monitor.panelWin;
   let { ACTIVITY_TYPE } = windowRequire("devtools/client/netmonitor/src/constants");
   let { EVENTS } = windowRequire("devtools/client/netmonitor/src/constants");
-  let { setPreferences, triggerActivity } =
-    windowRequire("devtools/client/netmonitor/src/connector/index");
+  let { setPreferences, triggerActivity } = connector;
   let {
     getSortedRequests,
   } = windowRequire("devtools/client/netmonitor/src/selectors/index");
diff --git a/devtools/client/netmonitor/test/head.js b/devtools/client/netmonitor/test/head.js
index 7a608ca9f287..dba5a42ba329 100644
--- a/devtools/client/netmonitor/test/head.js
+++ b/devtools/client/netmonitor/test/head.js
@@ -60,6 +60,7 @@ const CURL_URL = EXAMPLE_URL + "html_copy-as-curl.html";
 const CURL_UTILS_URL = EXAMPLE_URL + "html_curl-utils.html";
 const SEND_BEACON_URL = EXAMPLE_URL + "html_send-beacon.html";
 const CORS_URL = EXAMPLE_URL + "html_cors-test-page.html";
+const PAUSE_URL = EXAMPLE_URL + "html_pause-test-page.html";
 
 const SIMPLE_SJS = EXAMPLE_URL + "sjs_simple-test-server.sjs";
 const SIMPLE_UNSORTED_COOKIES_SJS = EXAMPLE_URL + "sjs_simple-unsorted-cookies-test-server.sjs";
@@ -176,9 +177,8 @@ function waitForTimelineMarkers(monitor) {
  */
 function waitForAllRequestsFinished(monitor) {
   let window = monitor.panelWin;
-  let { windowRequire } = window;
-  let { getNetworkRequest } =
-    windowRequire("devtools/client/netmonitor/src/connector/index");
+  let { connector } = window;
+  let { getNetworkRequest } = connector;
 
   return new Promise(resolve => {
     // Key is the request id, value is a boolean - is request finished or not?
@@ -290,9 +290,7 @@ function teardown(monitor) {
 function waitForNetworkEvents(monitor, getRequests, postRequests = 0) {
   return new Promise((resolve) => {
     let panel = monitor.panelWin;
-    let { windowRequire } = panel;
-    let { getNetworkRequest } =
-      windowRequire("devtools/client/netmonitor/src/connector/index");
+    let { getNetworkRequest } = panel.connector;
     let progress = {};
     let genericEvents = 0;
     let postEvents = 0;
diff --git a/devtools/client/netmonitor/test/html_pause-test-page.html b/devtools/client/netmonitor/test/html_pause-test-page.html
new file mode 100644
index 000000000000..c0d02f334f63
--- /dev/null
+++ b/devtools/client/netmonitor/test/html_pause-test-page.html
@@ -0,0 +1,37 @@
+<!-- Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/ -->
+<!doctype html>
+
+<html>
+  <head>
+    <meta charset="utf-8"/>
+    <meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate" />
+    <meta http-equiv="Pragma" content="no-cache" />
+    <meta http-equiv="Expires" content="0" />
+    <title>Network Monitor test page</title>
+  </head>
+
+  <body>
+    <p>Performing a custom number of GETs</p>
+
+    <script type="text/javascript">
+      /* exported performRequests */
+      "use strict";
+
+      function performRequests(url) {
+        return new Promise((resolve, reject) => {
+          let xhr = new XMLHttpRequest();
+          xhr.open("GET", url, true);
+
+          xhr.onreadystatechange = function () {
+            if (this.readyState == this.DONE) {
+              resolve();
+            }
+          };
+          xhr.send(null);
+        });
+      }
+    </script>
+  </body>
+
+</html>
diff --git a/devtools/client/performance/performance-controller.js b/devtools/client/performance/performance-controller.js
index 5d2724acec8a..bf53c248b024 100644
--- a/devtools/client/performance/performance-controller.js
+++ b/devtools/client/performance/performance-controller.js
@@ -517,18 +517,17 @@ var PerformanceController = {
    * @return {object}
    */
   getMultiprocessStatus: function () {
-    // If testing, set both supported and enabled to true so we
-    // have realtime rendering tests in non-e10s. This function is
-    // overridden wholesale in tests when we want to test multiprocess support
+    // If testing, set enabled to true so we have realtime rendering tests
+    // in non-e10s. This function is overridden wholesale in tests
+    // when we want to test multiprocess support
     // specifically.
     if (flags.testing) {
-      return { supported: true, enabled: true };
+      return { enabled: true };
     }
-    let supported = system.constants.E10S_TESTING_ONLY;
     // This is only checked on tool startup -- requires a restart if
     // e10s subsequently enabled.
     let enabled = this._e10s;
-    return { supported, enabled };
+    return { enabled };
   },
 
   /**
@@ -556,12 +555,9 @@ var PerformanceController = {
    * if e10s is not possible on the platform. If e10s is on, no attribute is set.
    */
   _setMultiprocessAttributes: function () {
-    let { enabled, supported } = this.getMultiprocessStatus();
-    if (!enabled && supported) {
+    let { enabled } = this.getMultiprocessStatus();
+    if (!enabled) {
       $("#performance-view").setAttribute("e10s", "disabled");
-    } else if (!enabled && !supported) {
-      // Could be a chance where the directive goes away yet e10s is still on
-      $("#performance-view").setAttribute("e10s", "unsupported");
     }
   },
 
diff --git a/devtools/client/performance/performance.xul b/devtools/client/performance/performance.xul
index 7ceb41c84851..effbc8f8b8d0 100644
--- a/devtools/client/performance/performance.xul
+++ b/devtools/client/performance/performance.xul
@@ -211,8 +211,6 @@
               <hbox pack="center">
                 <html:div class='recording-button-mount'/>
               </hbox>
-              <label class="realtime-disabled-message"
-                     value="&performanceUI.disabledRealTime.nonE10SBuild;"/>
               <label class="realtime-disabled-on-e10s-message"
                      value="&performanceUI.disabledRealTime.disabledE10S;"/>
               <label class="buffer-status-message"
@@ -237,8 +235,6 @@
                 <label class="console-profile-command" />
                 <label value="&performanceUI.console.stopCommandEnd;" />
               </hbox>
-              <label class="realtime-disabled-message"
-                     value="&performanceUI.disabledRealTime.nonE10SBuild;"/>
               <label class="realtime-disabled-on-e10s-message"
                      value="&performanceUI.disabledRealTime.disabledE10S;"/>
               <label class="buffer-status-message"
diff --git a/devtools/client/performance/test/browser_perf-recording-notices-05.js b/devtools/client/performance/test/browser_perf-recording-notices-05.js
index b6267470d19f..5107f81a6bad 100644
--- a/devtools/client/performance/test/browser_perf-recording-notices-05.js
+++ b/devtools/client/performance/test/browser_perf-recording-notices-05.js
@@ -20,35 +20,21 @@ add_task(function* () {
   // Set a fast profiler-status update interval
   yield gFront.setProfilerStatusInterval(10);
 
-  let supported = false;
   let enabled = false;
 
   PerformanceController.getMultiprocessStatus = () => {
-    return { supported, enabled };
+    return { enabled };
   };
 
-  PerformanceController._setMultiprocessAttributes();
-  ok($("#performance-view").getAttribute("e10s"), "unsupported",
-    "When e10s is disabled and no option to turn on, container has [e10s=unsupported].");
-
-  supported = true;
-  enabled = false;
   PerformanceController._setMultiprocessAttributes();
   ok($("#performance-view").getAttribute("e10s"), "disabled",
-    "When e10s is disabled and but is supported, container has [e10s=disabled].");
+    "When e10s is disabled, container has [e10s=disabled].");
 
-  supported = false;
   enabled = true;
+
   PerformanceController._setMultiprocessAttributes();
   ok($("#performance-view").getAttribute("e10s"), "",
-    "When e10s is enabled, but not supported, this probably means we no longer have " +
-    "E10S_TESTING_ONLY, and we have no e10s attribute.");
-
-  supported = true;
-  enabled = true;
-  PerformanceController._setMultiprocessAttributes();
-  ok($("#performance-view").getAttribute("e10s"), "",
-    "When e10s is enabled and supported, there should be no e10s attribute.");
+    "When e10s is enabled, there should be no e10s attribute.");
 
   yield teardownToolboxAndRemoveTab(panel);
 });
diff --git a/devtools/client/responsive.html/browser/swap.js b/devtools/client/responsive.html/browser/swap.js
index 13bc3be29980..77dba05841c1 100644
--- a/devtools/client/responsive.html/browser/swap.js
+++ b/devtools/client/responsive.html/browser/swap.js
@@ -8,6 +8,10 @@ const { Ci } = require("chrome");
 const { Task } = require("devtools/shared/task");
 const { tunnelToInnerBrowser } = require("./tunnel");
 
+function debug(msg) {
+  // console.log(`RDM swap: ${msg}`);
+}
+
 /**
  * Swap page content from an existing tab into a new browser within a container
  * page.  Page state is preserved by using `swapFrameLoaders`, just like when
@@ -70,6 +74,25 @@ function swapToInnerBrowser({ tab, containerURL, getInnerBrowser }) {
     gBrowser.swapBrowsersAndCloseOther(ourTab, otherTab);
   };
 
+  // It is possible for the frame loader swap within `gBrowser._swapBrowserDocShells` to
+  // fail when various frame state is either not ready yet or doesn't match between the
+  // two browsers you're trying to swap.  However, such errors are currently caught and
+  // silenced in the browser, because they are apparently expected in certain cases.
+  // So, here we do our own check to verify that the swap actually did in fact take place,
+  // making it much easier to track such errors when they happen.
+  let swapBrowserDocShells = (ourTab, otherBrowser) => {
+    // The verification step here assumes both browsers are remote.
+    if (!ourTab.linkedBrowser.isRemoteBrowser || !otherBrowser.isRemoteBrowser) {
+      throw new Error("Both browsers should be remote before swapping.");
+    }
+    let contentTabId = ourTab.linkedBrowser.frameLoader.tabParent.tabId;
+    gBrowser._swapBrowserDocShells(ourTab, otherBrowser);
+    if (otherBrowser.frameLoader.tabParent.tabId != contentTabId) {
+      // Bug 1408602: Try to unwind to save tab content from being lost.
+      throw new Error("Swapping tab content between browsers failed.");
+    }
+  };
+
   return {
 
     start: Task.async(function* () {
@@ -83,6 +106,7 @@ function swapToInnerBrowser({ tab, containerURL, getInnerBrowser }) {
       freezeNavigationState(tab);
 
       // 1. Create a temporary, hidden tab to load the tool UI.
+      debug("Add blank tool tab");
       let containerTab = addTabSilently("about:blank", {
         skipAnimation: true,
         forceNotRemote: true,
@@ -103,6 +127,7 @@ function swapToInnerBrowser({ tab, containerURL, getInnerBrowser }) {
         epoch: -1,
       });
       // Prevent the `containerURL` from ending up in the tab's history.
+      debug("Load container URL");
       containerBrowser.loadURIWithFlags(containerURL, {
         flags: Ci.nsIWebNavigation.LOAD_FLAGS_BYPASS_HISTORY,
       });
@@ -122,12 +147,15 @@ function swapToInnerBrowser({ tab, containerURL, getInnerBrowser }) {
       // Even worse than the delay, there appears to be no obvious event fired
       // after the frame is set lazily, so it's unclear how to know that work
       // has finished.
+      debug("Set container docShell active");
       containerBrowser.docShellIsActive = true;
 
       // 3. Create the initial viewport inside the tool UI.
       // The calling application will use container page loaded into the tab to
       // do whatever it needs to create the inner browser.
+      debug("Yield to container tab loaded");
       yield tabLoaded(containerTab);
+      debug("Yield to get inner browser");
       innerBrowser = yield getInnerBrowser(containerBrowser);
       addXULBrowserDecorations(innerBrowser);
       if (innerBrowser.isRemoteBrowser != tab.linkedBrowser.isRemoteBrowser) {
@@ -139,22 +167,26 @@ function swapToInnerBrowser({ tab, containerURL, getInnerBrowser }) {
       //    the viewport in the tool UI, preserving all state via
       //    `gBrowser._swapBrowserDocShells`.
       dispatchDevToolsBrowserSwap(tab.linkedBrowser, innerBrowser);
-      gBrowser._swapBrowserDocShells(tab, innerBrowser);
+      debug("Swap content to inner browser");
+      swapBrowserDocShells(tab, innerBrowser);
 
       // 5. Force the original browser tab to be non-remote since the tool UI
       //    must be loaded in the parent process, and we're about to swap the
       //    tool UI into this tab.
+      debug("Flip original tab to remote false");
       gBrowser.updateBrowserRemoteness(tab.linkedBrowser, false);
 
       // 6. Swap the tool UI (with viewport showing the content) into the
       //    original browser tab and close the temporary tab used to load the
       //    tool via `swapBrowsersAndCloseOther`.
+      debug("Swap tool UI to original tab");
       swapBrowsersAndCloseOtherSilently(tab, containerTab);
 
       // 7. Start a tunnel from the tool tab's browser to the viewport browser
       //    so that some browser UI functions, like navigation, are connected to
       //    the content in the viewport, instead of the tool page.
       tunnel = tunnelToInnerBrowser(tab.linkedBrowser, innerBrowser);
+      debug("Yield to tunnel start");
       yield tunnel.start();
 
       // Swapping browsers disconnects the find bar UI from the browser.
@@ -201,7 +233,7 @@ function swapToInnerBrowser({ tab, containerURL, getInnerBrowser }) {
       //    to the regular browser tab, preserving all state via
       //    `gBrowser._swapBrowserDocShells`.
       dispatchDevToolsBrowserSwap(innerBrowser, contentBrowser);
-      gBrowser._swapBrowserDocShells(contentTab, innerBrowser);
+      swapBrowserDocShells(contentTab, innerBrowser);
       innerBrowser = null;
 
       // Copy tab listener state flags to content tab.  See similar comment in `start`
diff --git a/devtools/client/responsive.html/components/Browser.js b/devtools/client/responsive.html/components/Browser.js
index c2a07baf6805..3847f921081a 100644
--- a/devtools/client/responsive.html/components/Browser.js
+++ b/devtools/client/responsive.html/components/Browser.js
@@ -6,14 +6,15 @@
 
 "use strict";
 
+const Services = require("Services");
 const { Task } = require("devtools/shared/task");
 const flags = require("devtools/shared/flags");
-const { getToplevelWindow } = require("../utils/window");
 const { DOM: dom, createClass, addons, PropTypes } =
   require("devtools/client/shared/vendor/react");
 
 const e10s = require("../utils/e10s");
 const message = require("../utils/message");
+const { getToplevelWindow } = require("../utils/window");
 
 const FRAME_SCRIPT = "resource://devtools/client/responsive.html/browser/content.js";
 
@@ -35,6 +36,27 @@ module.exports = createClass({
 
   mixins: [ addons.PureRenderMixin ],
 
+  /**
+   * Before the browser is mounted, listen for `remote-browser-shown` so that we know when
+   * the browser is fully ready.  Without waiting for an event such as this, we don't know
+   * whether all frame state for the browser is fully initialized (since some happens
+   * async after the element is added), and swapping browsers can fail if this state is
+   * not ready.
+   */
+  componentWillMount() {
+    this.browserShown = new Promise(resolve => {
+      let handler = frameLoader => {
+        let browser = this.refs.browserContainer.querySelector("iframe.browser");
+        if (frameLoader.ownerElement != browser) {
+          return;
+        }
+        Services.obs.removeObserver(handler, "remote-browser-shown");
+        resolve();
+      };
+      Services.obs.addObserver(handler, "remote-browser-shown");
+    });
+  },
+
   /**
    * Once the browser element has mounted, load the frame script and enable
    * various features, like floating scrollbars.
@@ -48,6 +70,7 @@ module.exports = createClass({
 
     // Notify manager.js that this browser has mounted, so that it can trigger
     // a swap if needed and continue with the rest of its startup.
+    yield this.browserShown;
     this.props.onBrowserMounted();
 
     // If we are swapping browsers after mount, wait for the swap to complete
@@ -101,9 +124,9 @@ module.exports = createClass({
 
   stopFrameScript: Task.async(function* () {
     let { onContentResize } = this;
-
     let browser = this.refs.browserContainer.querySelector("iframe.browser");
     let mm = browser.frameLoader.messageManager;
+
     e10s.off(mm, "OnContentResize", onContentResize);
     yield e10s.request(mm, "Stop");
     message.post(window, "stop-frame-script:done");
diff --git a/devtools/client/responsive.html/manager.js b/devtools/client/responsive.html/manager.js
index 2997f228b860..6f55585a8b5e 100644
--- a/devtools/client/responsive.html/manager.js
+++ b/devtools/client/responsive.html/manager.js
@@ -28,6 +28,10 @@ loader.lazyRequireGetter(this, "getStr",
 loader.lazyRequireGetter(this, "EmulationFront",
   "devtools/shared/fronts/emulation", true);
 
+function debug(msg) {
+  // console.log(`RDM manager: ${msg}`);
+}
+
 /**
  * ResponsiveUIManager is the external API for the browser UI, etc. to use when
  * opening and closing the responsive UI.
@@ -317,6 +321,8 @@ ResponsiveUI.prototype = {
    * For more details, see /devtools/docs/responsive-design-mode.md.
    */
   init: Task.async(function* () {
+    debug("Init start");
+
     let ui = this;
 
     // Watch for tab close and window close so we can clean up RDM synchronously
@@ -324,30 +330,38 @@ ResponsiveUI.prototype = {
     this.browserWindow.addEventListener("unload", this);
 
     // Swap page content from the current tab into a viewport within RDM
+    debug("Create browser swapper");
     this.swap = swapToInnerBrowser({
       tab: this.tab,
       containerURL: TOOL_URL,
       getInnerBrowser: Task.async(function* (containerBrowser) {
         let toolWindow = ui.toolWindow = containerBrowser.contentWindow;
         toolWindow.addEventListener("message", ui);
+        debug("Yield to init from inner");
         yield message.request(toolWindow, "init");
         toolWindow.addInitialViewport("about:blank");
+        debug("Yield to browser mounted");
         yield message.wait(toolWindow, "browser-mounted");
         return ui.getViewportBrowser();
       })
     });
+    debug("Yield to swap start");
     yield this.swap.start();
 
     this.tab.addEventListener("BeforeTabRemotenessChange", this);
 
     // Notify the inner browser to start the frame script
+    debug("Yield to start frame script");
     yield message.request(this.toolWindow, "start-frame-script");
 
     // Get the protocol ready to speak with emulation actor
+    debug("Yield to RDP server connect");
     yield this.connectToServer();
 
     // Non-blocking message to tool UI to start any delayed init activities
     message.post(this.toolWindow, "post-init");
+
+    debug("Init done");
   }),
 
   /**
diff --git a/devtools/client/styleeditor/StyleEditorUI.jsm b/devtools/client/styleeditor/StyleEditorUI.jsm
index e97e678a3be5..5cd48fa300ba 100644
--- a/devtools/client/styleeditor/StyleEditorUI.jsm
+++ b/devtools/client/styleeditor/StyleEditorUI.jsm
@@ -30,6 +30,7 @@ const {PrefObserver} = require("devtools/client/shared/prefs");
 const csscoverage = require("devtools/shared/fronts/csscoverage");
 const {console} = require("resource://gre/modules/Console.jsm");
 const {KeyCodes} = require("devtools/client/shared/keycodes");
+const {OriginalSource} = require("devtools/client/styleeditor/original-source");
 
 loader.lazyRequireGetter(this, "ResponsiveUIManager", "devtools/client/responsive.html/manager", true);
 
@@ -264,6 +265,7 @@ StyleEditorUI.prototype = {
       try {
         yield this._addStyleSheet(sheet);
       } catch (e) {
+        console.error(e);
         this.emit("error", { key: LOAD_ERROR });
       }
     }
@@ -332,11 +334,19 @@ StyleEditorUI.prototype = {
       let promise = (async () => {
         let editor = await this._addStyleSheetEditor(styleSheet, isNew);
 
-        if (!Services.prefs.getBoolPref(PREF_ORIG_SOURCES)) {
+        let toolbox = gDevTools.getToolbox(this._target);
+        let sourceMapService = toolbox.sourceMapService;
+        if (!sourceMapService) {
           return editor;
         }
 
-        let sources = await styleSheet.getOriginalSources();
+        let {href, nodeHref, actorID: id, sourceMapURL} = styleSheet;
+        let url = href || nodeHref;
+        let sources = await sourceMapService.getOriginalURLs({
+          id,
+          url,
+          sourceMapURL,
+        });
         // A single generated sheet might map to multiple original
         // sheets, so make editors for each of them.
         if (sources && sources.length) {
@@ -345,11 +355,14 @@ StyleEditorUI.prototype = {
           editor = null;
 
           for (let source of sources) {
+            let generatedId = sourceMapService.generatedToOriginalId(id, source);
+            let original = new OriginalSource(source, generatedId, sourceMapService);
+
             // set so the first sheet will be selected, even if it's a source
-            source.styleSheetIndex = styleSheet.styleSheetIndex;
-            source.relatedStyleSheet = styleSheet;
-            source.relatedEditorName = parentEditorName;
-            await this._addStyleSheetEditor(source);
+            original.styleSheetIndex = styleSheet.styleSheetIndex;
+            original.relatedStyleSheet = styleSheet;
+            original.relatedEditorName = parentEditorName;
+            await this._addStyleSheetEditor(original);
           }
         }
 
@@ -919,7 +932,9 @@ StyleEditorUI.prototype = {
           styleSheet: parentStyleSheet
         };
         if (editor.styleSheet.isOriginalSource) {
-          location = yield editor.cssSheet.getOriginalLocation(line, column);
+          let styleSheet = editor.cssSheet;
+          location = yield editor.styleSheet.getOriginalLocation(styleSheet, line,
+                                                                 column);
         }
 
         // this @media rule is from a different original source
diff --git a/devtools/client/styleeditor/StyleSheetEditor.jsm b/devtools/client/styleeditor/StyleSheetEditor.jsm
index 4f4554016795..49b8ba88fab4 100644
--- a/devtools/client/styleeditor/StyleSheetEditor.jsm
+++ b/devtools/client/styleeditor/StyleSheetEditor.jsm
@@ -297,6 +297,7 @@ StyleSheetEditor.prototype = {
                      ", the editor was destroyed");
         console.error(e);
       } else {
+        console.error(e);
         this.emit("error", { key: LOAD_ERROR, append: this.styleSheet.href });
         throw e;
       }
diff --git a/devtools/client/styleeditor/moz.build b/devtools/client/styleeditor/moz.build
index e19aa4c798e3..bf0e0ada243c 100644
--- a/devtools/client/styleeditor/moz.build
+++ b/devtools/client/styleeditor/moz.build
@@ -7,6 +7,7 @@
 BROWSER_CHROME_MANIFESTS += ['test/browser.ini']
 
 DevToolsModules(
+    'original-source.js',
     'styleeditor-commands.js',
     'styleeditor-panel.js',
     'StyleEditorUI.jsm',
diff --git a/devtools/client/styleeditor/original-source.js b/devtools/client/styleeditor/original-source.js
new file mode 100644
index 000000000000..3c5bb4fe13bb
--- /dev/null
+++ b/devtools/client/styleeditor/original-source.js
@@ -0,0 +1,99 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * An object of this type represents an original source for the style
+ * editor.  An "original" source is one that is mentioned in a source
+ * map.
+ *
+ * @param {String} url
+ *        The URL of the original source.
+ * @param {String} sourceID
+ *        The source ID of the original source, as used by the source
+ *        map service.
+ * @param {SourceMapService} sourceMapService
+ *        The source map service; @see Toolbox.sourceMapService
+ */
+function OriginalSource(url, sourceId, sourceMapService) {
+  this.isOriginalSource = true;
+
+  this._url = url;
+  this._sourceId = sourceId;
+  this._sourceMapService = sourceMapService;
+}
+
+OriginalSource.prototype = {
+  /** Get the original source's URL.  */
+  get url() {
+    return this._url;
+  },
+
+  /** Get the original source's URL.  */
+  get href() {
+    return this._url;
+  },
+
+  /**
+   * Return a promise that will resolve to the original source's full
+   * text.  The return result is actually an object with a single
+   * `string` method; this method will return the source text as a
+   * string.  This is done because the style editor elsewhere expects
+   * a long string actor.
+   */
+  getText: function () {
+    if (!this._sourcePromise) {
+      this._sourcePromise = this._sourceMapService.getOriginalSourceText({
+        id: this._sourceId,
+        url: this._url,
+      }).then(contents => {
+        // Make it look like a long string actor.
+        return {
+          string: () => contents.text,
+        };
+      });
+    }
+    return this._sourcePromise;
+  },
+
+  /**
+   * Given a source-mapped, generated style sheet, a line, and a
+   * column, return the corresponding original location in this style
+   * sheet.
+   *
+   * @param {StyleSheetFront} relatedSheet
+   *        The generated style sheet's actor
+   * @param {Number} line
+   *        Line number.
+   * @param {Number} column
+   *        Column number.
+   * @return {Location}
+   *        The original location, an object with at least
+   *        `sourceUrl`, `source`, `styleSheet`, `line`, and `column`
+   *        properties.
+   */
+  getOriginalLocation: function (relatedSheet, line, column) {
+    let {href, nodeHref, actorID: sourceId} = relatedSheet;
+    let sourceUrl = href || nodeHref;
+    return this._sourceMapService.getOriginalLocation({
+      sourceId,
+      line,
+      column,
+      sourceUrl,
+    }).then(location => {
+      // Add some properties for the style editor.
+      location.source = location.sourceUrl;
+      location.styleSheet = relatedSheet;
+      return location;
+    });
+  },
+
+  // Dummy implementations, as we never emit an event.
+  on: function () { },
+  off: function () { },
+};
+
+exports.OriginalSource = OriginalSource;
diff --git a/devtools/client/styleeditor/test/browser_styleeditor_media_sidebar_sourcemaps.js b/devtools/client/styleeditor/test/browser_styleeditor_media_sidebar_sourcemaps.js
index 43ce8b246dec..45b83005d584 100644
--- a/devtools/client/styleeditor/test/browser_styleeditor_media_sidebar_sourcemaps.js
+++ b/devtools/client/styleeditor/test/browser_styleeditor_media_sidebar_sourcemaps.js
@@ -17,9 +17,7 @@ waitForExplicitFinish();
 add_task(function* () {
   Services.prefs.setBoolPref(MAP_PREF, true);
 
-  let { ui, onMediaListChanged } = yield openStyleEditorForURL(TESTCASE_URI);
-
-  yield onMediaListChanged;
+  let { ui } = yield openStyleEditorForURL(TESTCASE_URI);
 
   is(ui.editors.length, 1, "correct number of editors");
 
diff --git a/devtools/client/styleeditor/test/head.js b/devtools/client/styleeditor/test/head.js
index dc5db945c4e1..8d5492a72d53 100644
--- a/devtools/client/styleeditor/test/head.js
+++ b/devtools/client/styleeditor/test/head.js
@@ -82,15 +82,11 @@ var openStyleEditor = Task.async(function* (tab) {
   let panel = toolbox.getPanel("styleeditor");
   let ui = panel.UI;
 
-  // This event is sometimes needed by tests, but may be emitted before the list
-  // animation is done. So we listen to it here so tests don't have to and can't miss it.
-  let onMediaListChanged = ui.once("media-list-changed");
-
   // The stylesheet list appears with an animation. Let this animation finish.
   let animations = ui._root.getAnimations({subtree: true});
   yield Promise.all(animations.map(a => a.finished));
 
-  return { toolbox, panel, ui, onMediaListChanged };
+  return { toolbox, panel, ui };
 });
 
 /**
diff --git a/devtools/client/themes/performance.css b/devtools/client/themes/performance.css
index 28887dc25f98..794a1a267d9d 100644
--- a/devtools/client/themes/performance.css
+++ b/devtools/client/themes/performance.css
@@ -247,13 +247,11 @@
   margin: 3px 2px;
 }
 
-.realtime-disabled-message,
 .realtime-disabled-on-e10s-message {
   display: none;
 }
 
-#performance-view[e10s="disabled"] .realtime-disabled-on-e10s-message,
-#performance-view[e10s="unsupported"] .realtime-disabled-message {
+#performance-view[e10s="disabled"] .realtime-disabled-on-e10s-message {
   display: initial;
   opacity: 0.5;
 }
diff --git a/devtools/client/webconsole/new-console-output/components/message-types/EvaluationResult.js b/devtools/client/webconsole/new-console-output/components/message-types/EvaluationResult.js
index 632a0c474e51..f7785149411a 100644
--- a/devtools/client/webconsole/new-console-output/components/message-types/EvaluationResult.js
+++ b/devtools/client/webconsole/new-console-output/components/message-types/EvaluationResult.js
@@ -59,7 +59,7 @@ function EvaluationResult(props) {
     messageBody = GripMessageBody({
       dispatch,
       messageId,
-      grip: parameters,
+      grip: parameters[0],
       serviceContainer,
       useQuotes: true,
       escapeWhitespace: false,
diff --git a/devtools/client/webconsole/new-console-output/components/message-types/NetworkEventMessage.js b/devtools/client/webconsole/new-console-output/components/message-types/NetworkEventMessage.js
index 8058be0c73ac..be3b42013aac 100644
--- a/devtools/client/webconsole/new-console-output/components/message-types/NetworkEventMessage.js
+++ b/devtools/client/webconsole/new-console-output/components/message-types/NetworkEventMessage.js
@@ -92,18 +92,35 @@ function NetworkEventMessage({
   const xhr = isXHR
     ? dom.span({ className: "xhr" }, l10n.getStr("webConsoleXhrIndicator"))
     : null;
-  const url = dom.a({ className: "url", title: request.url, onClick: toggle },
+  const requestUrl = dom.a({ className: "url", title: request.url, onClick: toggle },
     request.url.replace(/\?.+/, ""));
   const statusBody = statusInfo
     ? dom.a({ className: "status", onClick: toggle }, statusInfo)
     : null;
 
-  const messageBody = [method, xhr, url, statusBody];
+  const messageBody = [method, xhr, requestUrl, statusBody];
+
+  // API consumed by Net monitor UI components. Most of the method
+  // are not needed in context of the Console panel (atm) and thus
+  // let's just provide empty implementation.
+  // Individual methods might be implemented step by step as needed.
+  let connector = {
+    viewSourceInDebugger: (url, line) => {
+      serviceContainer.onViewSourceInDebugger({url, line});
+    },
+    getLongString: () => {},
+    getTabTarget: () => {},
+    getNetworkRequest: () => {},
+    sendHTTPRequest: () => {},
+    setPreferences: () => {},
+    triggerActivity: () => {},
+  };
 
   // Only render the attachment if the network-event is
   // actually opened (performance optimization).
   const attachment = open && dom.div({className: "network-info devtools-monospace"},
     TabboxPanel({
+      connector,
       activeTabId: networkMessageActiveTabId,
       request: networkMessageUpdate,
       sourceMapService: serviceContainer.sourceMapService,
diff --git a/devtools/client/webconsole/new-console-output/new-console-output-wrapper.js b/devtools/client/webconsole/new-console-output/new-console-output-wrapper.js
index 178b86c3411e..e5eb816780d6 100644
--- a/devtools/client/webconsole/new-console-output/new-console-output-wrapper.js
+++ b/devtools/client/webconsole/new-console-output/new-console-output-wrapper.js
@@ -139,9 +139,7 @@ NewConsoleOutputWrapper.prototype = {
         ),
         openNetworkPanel: (requestId) => {
           return this.toolbox.selectTool("netmonitor").then((panel) => {
-            let { inspectRequest } = panel.panelWin.windowRequire(
-              "devtools/client/netmonitor/src/connector/index");
-            return inspectRequest(requestId);
+            return panel.panelWin.Netmonitor.inspectRequest(requestId);
           });
         },
         sourceMapService: this.toolbox ? this.toolbox.sourceMapURLService : null,
diff --git a/devtools/client/webconsole/new-console-output/reducers/messages.js b/devtools/client/webconsole/new-console-output/reducers/messages.js
index 4f08f2b4d0b6..3a3b1c219af0 100644
--- a/devtools/client/webconsole/new-console-output/reducers/messages.js
+++ b/devtools/client/webconsole/new-console-output/reducers/messages.js
@@ -480,17 +480,23 @@ function limitTopLevelMessageCount(state, logLimit) {
  * @return {Array} An array containing all the actors logged in a message.
  */
 function getAllActorsInMessage(message, state) {
-  // Messages without argument cannot be associated with backend actors.
-  if (!message || !Array.isArray(message.parameters) || message.parameters.length === 0) {
-    return [];
+  const {
+    parameters,
+    messageText,
+  } = message;
+
+  let actors = [];
+  if (Array.isArray(parameters)) {
+    message.parameters.forEach(parameter => {
+      if (parameter.actor) {
+        actors.push(parameter.actor);
+      }
+    });
   }
 
-  const actors = [...message.parameters.reduce((res, parameter) => {
-    if (parameter.actor) {
-      res.push(parameter.actor);
-    }
-    return res;
-  }, [])];
+  if (messageText && messageText.actor) {
+    actors.push(messageText.actor);
+  }
 
   return actors;
 }
diff --git a/devtools/client/webconsole/new-console-output/test/fixtures/stubs/evaluationResult.js b/devtools/client/webconsole/new-console-output/test/fixtures/stubs/evaluationResult.js
index f133f263f1d9..350f03c7965f 100644
--- a/devtools/client/webconsole/new-console-output/test/fixtures/stubs/evaluationResult.js
+++ b/devtools/client/webconsole/new-console-output/test/fixtures/stubs/evaluationResult.js
@@ -21,19 +21,21 @@ stubPreparedMessages.set("new Date(0)", new ConsoleMessage({
   "type": "result",
   "helperType": null,
   "level": "log",
-  "parameters": {
-    "type": "object",
-    "actor": "server1.conn0.child1/obj30",
-    "class": "Date",
-    "extensible": true,
-    "frozen": false,
-    "sealed": false,
-    "ownPropertyLength": 0,
-    "preview": {
-      "timestamp": 0
+  "parameters": [
+    {
+      "type": "object",
+      "actor": "server1.conn0.child1/obj30",
+      "class": "Date",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 0,
+      "preview": {
+        "timestamp": 0
+      }
     }
-  },
-  "repeatId": "{\"frame\":null,\"groupId\":null,\"indent\":0,\"level\":\"log\",\"parameters\":{\"type\":\"object\",\"actor\":\"server1.conn0.child1/obj30\",\"class\":\"Date\",\"extensible\":true,\"frozen\":false,\"sealed\":false,\"ownPropertyLength\":0,\"preview\":{\"timestamp\":0}},\"source\":\"javascript\",\"type\":\"result\",\"userProvidedStyles\":null}",
+  ],
+  "repeatId": "{\"frame\":null,\"groupId\":null,\"indent\":0,\"level\":\"log\",\"parameters\":[{\"type\":\"object\",\"actor\":\"server1.conn0.child1/obj30\",\"class\":\"Date\",\"extensible\":true,\"frozen\":false,\"sealed\":false,\"ownPropertyLength\":0,\"preview\":{\"timestamp\":0}}],\"source\":\"javascript\",\"type\":\"result\",\"userProvidedStyles\":null}",
   "stacktrace": null,
   "frame": null,
   "groupId": null,
@@ -51,10 +53,12 @@ stubPreparedMessages.set("asdf()", new ConsoleMessage({
   "helperType": null,
   "level": "error",
   "messageText": "ReferenceError: asdf is not defined",
-  "parameters": {
-    "type": "undefined"
-  },
-  "repeatId": "{\"frame\":{\"source\":\"debugger eval code\",\"line\":1,\"column\":1},\"groupId\":null,\"indent\":0,\"level\":\"error\",\"messageText\":\"ReferenceError: asdf is not defined\",\"parameters\":{\"type\":\"undefined\"},\"source\":\"javascript\",\"type\":\"result\",\"userProvidedStyles\":null}",
+  "parameters": [
+    {
+      "type": "undefined"
+    }
+  ],
+  "repeatId": "{\"frame\":{\"source\":\"debugger eval code\",\"line\":1,\"column\":1},\"groupId\":null,\"indent\":0,\"level\":\"error\",\"messageText\":\"ReferenceError: asdf is not defined\",\"parameters\":[{\"type\":\"undefined\"}],\"source\":\"javascript\",\"type\":\"result\",\"userProvidedStyles\":null}",
   "stacktrace": null,
   "frame": {
     "source": "debugger eval code",
@@ -77,10 +81,12 @@ stubPreparedMessages.set("1 + @", new ConsoleMessage({
   "helperType": null,
   "level": "error",
   "messageText": "SyntaxError: illegal character",
-  "parameters": {
-    "type": "undefined"
-  },
-  "repeatId": "{\"frame\":{\"source\":\"debugger eval code\",\"line\":1,\"column\":4},\"groupId\":null,\"indent\":0,\"level\":\"error\",\"messageText\":\"SyntaxError: illegal character\",\"parameters\":{\"type\":\"undefined\"},\"source\":\"javascript\",\"type\":\"result\",\"userProvidedStyles\":null}",
+  "parameters": [
+    {
+      "type": "undefined"
+    }
+  ],
+  "repeatId": "{\"frame\":{\"source\":\"debugger eval code\",\"line\":1,\"column\":4},\"groupId\":null,\"indent\":0,\"level\":\"error\",\"messageText\":\"SyntaxError: illegal character\",\"parameters\":[{\"type\":\"undefined\"}],\"source\":\"javascript\",\"type\":\"result\",\"userProvidedStyles\":null}",
   "stacktrace": null,
   "frame": {
     "source": "debugger eval code",
@@ -102,31 +108,33 @@ stubPreparedMessages.set("inspect({a: 1})", new ConsoleMessage({
   "type": "result",
   "helperType": "inspectObject",
   "level": "log",
-  "parameters": {
-    "type": "object",
-    "actor": "server1.conn0.child1/obj35",
-    "class": "Object",
-    "extensible": true,
-    "frozen": false,
-    "sealed": false,
-    "ownPropertyLength": 1,
-    "preview": {
-      "kind": "Object",
-      "ownProperties": {
-        "a": {
-          "configurable": true,
-          "enumerable": true,
-          "writable": true,
-          "value": 1
-        }
-      },
-      "ownSymbols": [],
-      "ownPropertiesLength": 1,
-      "ownSymbolsLength": 0,
-      "safeGetterValues": {}
+  "parameters": [
+    {
+      "type": "object",
+      "actor": "server1.conn0.child1/obj35",
+      "class": "Object",
+      "extensible": true,
+      "frozen": false,
+      "sealed": false,
+      "ownPropertyLength": 1,
+      "preview": {
+        "kind": "Object",
+        "ownProperties": {
+          "a": {
+            "configurable": true,
+            "enumerable": true,
+            "writable": true,
+            "value": 1
+          }
+        },
+        "ownSymbols": [],
+        "ownPropertiesLength": 1,
+        "ownSymbolsLength": 0,
+        "safeGetterValues": {}
+      }
     }
-  },
-  "repeatId": "{\"frame\":null,\"groupId\":null,\"indent\":0,\"level\":\"log\",\"parameters\":{\"type\":\"object\",\"actor\":\"server1.conn0.child1/obj35\",\"class\":\"Object\",\"extensible\":true,\"frozen\":false,\"sealed\":false,\"ownPropertyLength\":1,\"preview\":{\"kind\":\"Object\",\"ownProperties\":{\"a\":{\"configurable\":true,\"enumerable\":true,\"writable\":true,\"value\":1}},\"ownSymbols\":[],\"ownPropertiesLength\":1,\"ownSymbolsLength\":0,\"safeGetterValues\":{}}},\"source\":\"javascript\",\"type\":\"result\",\"userProvidedStyles\":null}",
+  ],
+  "repeatId": "{\"frame\":null,\"groupId\":null,\"indent\":0,\"level\":\"log\",\"parameters\":[{\"type\":\"object\",\"actor\":\"server1.conn0.child1/obj35\",\"class\":\"Object\",\"extensible\":true,\"frozen\":false,\"sealed\":false,\"ownPropertyLength\":1,\"preview\":{\"kind\":\"Object\",\"ownProperties\":{\"a\":{\"configurable\":true,\"enumerable\":true,\"writable\":true,\"value\":1}},\"ownSymbols\":[],\"ownPropertiesLength\":1,\"ownSymbolsLength\":0,\"safeGetterValues\":{}}}],\"source\":\"javascript\",\"type\":\"result\",\"userProvidedStyles\":null}",
   "stacktrace": null,
   "frame": null,
   "groupId": null,
@@ -149,10 +157,12 @@ stubPreparedMessages.set("longString message Error", new ConsoleMessage({
     "length": 110007,
     "actor": "server1.conn0.child1/longString37"
   },
-  "parameters": {
-    "type": "undefined"
-  },
-  "repeatId": "{\"frame\":null,\"groupId\":null,\"indent\":0,\"level\":\"error\",\"messageText\":{\"type\":\"longString\",\"initial\":\"Error: Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Lon\",\"length\":110007,\"actor\":\"server1.conn0.child1/longString37\"},\"parameters\":{\"type\":\"undefined\"},\"source\":\"javascript\",\"type\":\"result\",\"userProvidedStyles\":null}",
+  "parameters": [
+    {
+      "type": "undefined"
+    }
+  ],
+  "repeatId": "{\"frame\":null,\"groupId\":null,\"indent\":0,\"level\":\"error\",\"messageText\":{\"type\":\"longString\",\"initial\":\"Error: Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Long error Lon\",\"length\":110007,\"actor\":\"server1.conn0.child1/longString37\"},\"parameters\":[{\"type\":\"undefined\"}],\"source\":\"javascript\",\"type\":\"result\",\"userProvidedStyles\":null}",
   "stacktrace": null,
   "frame": null,
   "groupId": null,
diff --git a/devtools/client/webconsole/new-console-output/test/mochitest/browser.ini b/devtools/client/webconsole/new-console-output/test/mochitest/browser.ini
index 2ed1088465b8..c81d2f0196eb 100644
--- a/devtools/client/webconsole/new-console-output/test/mochitest/browser.ini
+++ b/devtools/client/webconsole/new-console-output/test/mochitest/browser.ini
@@ -166,7 +166,6 @@ support-files =
   !/devtools/client/netmonitor/test/sjs_cors-test-server.sjs
   !/image/test/mochitest/blue.png
   !/devtools/client/framework/test/shared-head.js
-
 [browser_console.js]
 skip-if = true # Bug 1406060
 [browser_console_addonsdk_loader_exception.js]
@@ -202,18 +201,17 @@ subsuite = clipboard
 # old console skip-if = (os == 'linux' && bits == 32 && debug) # bug 1328915, disable linux32 debug devtools for timeouts
 [browser_jsterm_dollar.js]
 [browser_jsterm_history_persist.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408870
 [browser_jsterm_inspect.js]
 [browser_jsterm_no_autocompletion_on_defined_variables.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408872
 [browser_jsterm_no_input_and_tab_key_pressed.js]
+[browser_jsterm_no_input_change_and_tab_key_pressed.js]
 [browser_netmonitor_shows_reqs_in_webconsole.js]
 [browser_webconsole.js]
 skip-if = true #	Bug 1404829
-[browser_webconsole_No_input_change_and_Tab_key_pressed.js]
-skip-if = true #	Bug 1404882
 [browser_webconsole_add_edited_input_to_history.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408915
 [browser_webconsole_allow_mixedcontent_securityerrors.js]
 tags = mcb
 skip-if = true #	Bug 1403452
@@ -221,56 +219,56 @@ skip-if = true #	Bug 1403452
 [browser_webconsole_assert.js]
 skip-if = true #	Bug 1403458
 [browser_webconsole_autocomplete-properties-with-non-alphanumeric-names.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408916
 [browser_webconsole_autocomplete_JSTerm_helpers.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408917
 [browser_webconsole_autocomplete_accessibility.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408918
 [browser_webconsole_autocomplete_and_selfxss.js]
 subsuite = clipboard
 skip-if = true #	Bug 1404850
 # old console skip-if = (os == 'linux' && bits == 32 && debug) # bug 1328915, disable linux32 debug devtools for timeouts
 [browser_webconsole_autocomplete_crossdomain_iframe.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408919
 [browser_webconsole_autocomplete_in_debugger_stackframe.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408920
 [browser_webconsole_autocomplete_keys.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408921
 [browser_webconsole_autocomplete_popup.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408922
 [browser_webconsole_autocomplete_popup_close_on_tab_switch.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408923
 [browser_webconsole_batching.js]
 [browser_webconsole_block_mixedcontent_securityerrors.js]
 tags = mcb
 skip-if = true #	Bug 1403899
 # old console skip-if = (os == 'win' && bits == 64) # Bug 1390001
 [browser_webconsole_cached_autocomplete.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408924
 [browser_webconsole_cached_messages.js]
 skip-if = true #	Bug 1406069
 [browser_webconsole_cd_iframe.js]
 skip-if = true #	Bug 1406030
 [browser_webconsole_certificate_messages.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408925
 # old console skip-if = e10s # Bug 1042253 - webconsole tests disabled with e10s
 [browser_webconsole_charset.js]
 skip-if = true #	Bug 1404400
 [browser_webconsole_chrome.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408926
 [browser_webconsole_click_function_to_source.js]
 skip-if = true #	Bug 1406038
 [browser_webconsole_clickable_urls.js]
 [browser_webconsole_closing_after_completion.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408927
 [browser_webconsole_closing_brackets.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408928
 [browser_webconsole_closure_inspection.js]
 skip-if = true #	Bug 1405250
 [browser_webconsole_completion.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408929
 [browser_webconsole_console_api_iframe.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408930
 [browser_webconsole_console_dir.js]
 [browser_webconsole_console_dir_uninspectable.js]
 skip-if = true #	Bug 1403449
@@ -295,16 +293,16 @@ skip-if = true #	Bug 1401958
 [browser_webconsole_copy_link_location.js]
 skip-if = true #	Bug 1401944
 [browser_webconsole_csp_ignore_reflected_xss_message.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408931
 # old console skip-if = (e10s && debug) || (e10s && os == 'win') # Bug 1221499 enabled these on windows
 [browser_webconsole_cspro.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408932
 # old console skip-if = e10s && (os == 'win' || os == 'mac') # Bug 1243967
 [browser_webconsole_ctrl_key_nav.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408933
 # old console skip-if = os != "mac"
 [browser_webconsole_deactivateHUDForContext_unfocused_window.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408934
 [browser_webconsole_document_body_autocomplete.js]
 skip-if = true #	Bug 1404851
 [browser_webconsole_document_focus.js]
@@ -312,15 +310,15 @@ skip-if = true #	Bug 1404368
 [browser_webconsole_duplicate_errors.js]
 skip-if = true #	Bug 1403907
 [browser_webconsole_errors_after_page_reload.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408935
 [browser_webconsole_eval_in_debugger_stackframe.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408936
 [browser_webconsole_eval_in_debugger_stackframe2.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408893
 [browser_webconsole_execution_scope.js]
 skip-if = true #	Bug 1405333
 [browser_webconsole_external_script_errors.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408937
 [browser_webconsole_file_uri.js]
 skip-if = true #	Bug 1404382
 [browser_webconsole_filter_scroll.js]
@@ -331,11 +329,11 @@ skip-if = true #	Bug 1404392
 skip-if = true #	Bug 1404853
 # old console skip-if = true # Requires direct access to content nodes
 [browser_webconsole_history.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408938
 [browser_webconsole_history_arrow_keys.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408939
 [browser_webconsole_history_nav.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408940
 [browser_webconsole_hpkp_invalid-headers.js]
 skip-if = true #	Bug 1405340
 # old console skip-if = (os == 'win' && bits == 64) # Bug 1390001
@@ -388,17 +386,17 @@ skip-if = true #	Bug 1404384
 tags = mcb
 skip-if = true #	Bug 1404886
 [browser_webconsole_multiline_input.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408941
 [browser_webconsole_multiple_windows_and_tabs.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408942
 [browser_webconsole_netlogging_reset_filter.js]
 skip-if = true #	Bug 1405636
 [browser_webconsole_network_exceptions.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408943
 [browser_webconsole_network_messages_expand.js]
 [browser_webconsole_network_messages_openinnet.js]
 [browser_webconsole_network_requests_from_chrome.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408944
 [browser_webconsole_nodes_highlight.js]
 [browser_webconsole_nodes_select.js]
 [browser_webconsole_notifications.js]
@@ -407,7 +405,7 @@ skip-if = true #	Bug 1405637
 [browser_webconsole_object_inspector_entries.js]
 [browser_webconsole_observer_notifications.js]
 [browser_webconsole_optimized_out_vars.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408945
 [browser_webconsole_output_copy.js]
 subsuite = clipboard
 skip-if = true #	Bug 1404364
@@ -417,7 +415,7 @@ subsuite = clipboard
 skip-if = true #	Bug 1405641
 # old console skip-if = (os == 'linux' && bits == 32 && debug) # bug 1328915, disable linux32 debug devtools for timeouts
 [browser_webconsole_output_order.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408946
 [browser_webconsole_persist.js]
 [browser_webconsole_property_provider.js]
 skip-if = true # Bug 1406841
@@ -427,7 +425,7 @@ skip-if = true #	Bug 1404832
 [browser_webconsole_reflow.js]
 skip-if = true #	Bug 1406022
 [browser_webconsole_reopen_closed_tab.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408947
 [browser_webconsole_repeat_different_objects.js]
 skip-if = true #	Bug 1401953
 [browser_webconsole_repeated_messages_accuracy.js]
@@ -441,7 +439,7 @@ skip-if = true #	Bug 1403454
 [browser_webconsole_select_all.js]
 skip-if = true #	Bug 1404359
 [browser_webconsole_show_subresource_security_errors.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408948
 # old console skip-if = e10s && (os == 'win' || os == 'mac') # Bug 1243987
 [browser_webconsole_shows_reqs_in_netmonitor.js]
 [browser_webconsole_sourcemap_css.js]
@@ -449,7 +447,7 @@ skip-if = true # Bug 1401881
 [browser_webconsole_sourcemap_invalid.js]
 [browser_webconsole_sourcemap_nosource.js]
 [browser_webconsole_split.js]
-skip-if = true # Bug 1401881
+skip-if = true # Bug 1408949
 [browser_webconsole_split_escape_key.js]
 skip-if = true #	Bug 1405647
 [browser_webconsole_split_focus.js]
@@ -482,4 +480,4 @@ skip-if = true #	Bug 1405245
 # old console skip-if = e10s && (os == 'win') # Bug 1264955
 [browser_webconsole_warn_about_replaced_api.js]
 [browser_webconsole_websocket.js]
-skip-if = true # Bug 1401881
\ No newline at end of file
+skip-if = true # Bug 1408950
\ No newline at end of file
diff --git a/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_No_input_change_and_Tab_key_pressed.js b/devtools/client/webconsole/new-console-output/test/mochitest/browser_jsterm_no_input_change_and_tab_key_pressed.js
similarity index 60%
rename from devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_No_input_change_and_Tab_key_pressed.js
rename to devtools/client/webconsole/new-console-output/test/mochitest/browser_jsterm_no_input_change_and_tab_key_pressed.js
index fd4e802fb670..6a3ca6d1cbac 100644
--- a/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_No_input_change_and_Tab_key_pressed.js
+++ b/devtools/client/webconsole/new-console-output/test/mochitest/browser_jsterm_no_input_change_and_tab_key_pressed.js
@@ -7,31 +7,27 @@
 
 // See Bug 734061.
 
-const TEST_URI = "http://example.com/browser/devtools/client/webconsole/" +
-                 "test/browser/test-console.html";
+const TEST_URI = "data:text/html,Testing jsterm focus";
 
 add_task(function* () {
-  yield loadTab(TEST_URI);
-
-  let hud = yield openConsole();
-
+  let hud = yield openNewTabAndConsole(TEST_URI);
   let jsterm = hud.jsterm;
   let input = jsterm.inputNode;
 
-  is(input.getAttribute("focused"), "true", "input has focus");
+  is(hasFocus(input), true, "input has focus");
   EventUtils.synthesizeKey("VK_TAB", {});
-  is(input.getAttribute("focused"), "", "focus moved away");
+  is(hasFocus(input), false, "focus moved away");
 
   // Test user changed something
   input.focus();
   EventUtils.synthesizeKey("A", {});
   EventUtils.synthesizeKey("VK_TAB", {});
-  is(input.getAttribute("focused"), "true", "input is still focused");
+  is(hasFocus(input), true, "input is still focused");
 
   // Test non empty input but not changed since last focus
   input.blur();
   input.focus();
   EventUtils.synthesizeKey("VK_RIGHT", {});
   EventUtils.synthesizeKey("VK_TAB", {});
-  is(input.getAttribute("focused"), "", "input moved away");
+  is(hasFocus(input), false, "focus moved away");
 });
diff --git a/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_inspect_cross_domain_object.js b/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_inspect_cross_domain_object.js
index 685148fc7155..d6f4d1ff2ee3 100644
--- a/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_inspect_cross_domain_object.js
+++ b/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_inspect_cross_domain_object.js
@@ -39,10 +39,22 @@ add_task(function* () {
 
   let body = msg.querySelector(".message-body");
   ok(body, "message body");
-
-  let clickable = result.clickableElements[0];
-  ok(clickable, "clickable object found");
   ok(body.textContent.includes('{ hello: "world!",'), "message text check");
+  ok(body.textContent.includes('function func()'), "message text check");
+
+  yield testClickable(result.clickableElements[0], [
+    { name: "hello", value: "world!" },
+    { name: "bug", value: 869003 },
+  ], hud);
+  yield testClickable(result.clickableElements[1], [
+    { name: "hello", value: "world!" },
+    { name: "name", value: "func" },
+    { name: "length", value: 1 },
+  ], hud);
+});
+
+function* testClickable(clickable, props, hud) {
+  ok(clickable, "clickable object found");
 
   executeSoon(() => {
     EventUtils.synthesizeMouse(clickable, 2, 2, {}, hud.iframeWindow);
@@ -52,13 +64,9 @@ add_task(function* () {
   ok(aVar, "variables view fetched");
   ok(aVar._variablesView, "variables view object");
 
-  [result] = yield findVariableViewProperties(aVar, [
-    { name: "hello", value: "world!" },
-    { name: "bug", value: 869003 },
-  ], { webconsole: hud });
-
+  let [result] = yield findVariableViewProperties(aVar, props, { webconsole: hud });
   let prop = result.matchedProp;
-  ok(prop, "matched the |hello| property in the variables view");
+  ok(prop, "matched the |" + props[0].name + "| property in the variables view");
 
   // Check that property value updates work.
   aVar = yield updateVariablesViewProperty({
@@ -70,8 +78,6 @@ add_task(function* () {
 
   info("onFetchAfterUpdate");
 
-  yield findVariableViewProperties(aVar, [
-    { name: "hello", value: "omgtest" },
-    { name: "bug", value: 869003 },
-  ], { webconsole: hud });
-});
+  props[0].value = "omgtest";
+  yield findVariableViewProperties(aVar, props, { webconsole: hud });
+}
diff --git a/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_network_messages_expand.js b/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_network_messages_expand.js
index 6bd5c5163b7b..14b84679dfc7 100644
--- a/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_network_messages_expand.js
+++ b/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_network_messages_expand.js
@@ -63,13 +63,12 @@ async function testNetworkMessage(messageNode) {
 
   // Select Response tab and check the content. CodeMirror initialization
   // is delayed  to prevent UI freeze, so wait for a little while.
-  // TODO: Bug 1406100 - The 'responseContent' network event update is missing sometimes
-  /* responseTab.click();
+  responseTab.click();
   await waitForSourceEditor(messageNode);
   let responseContent = messageNode.querySelector(
     "#response-panel .editor-row-container .CodeMirror");
   ok(responseContent, "Response content is available");
-  ok(responseContent.textContent, "Response text is available"); */
+  ok(responseContent.textContent, "Response text is available");
 
   // Select Timings tab and check the content.
   timingsTab.click();
@@ -92,9 +91,9 @@ async function waitForNetworkUpdates(toolbox) {
   });
 }
 
-/* async function waitForSourceEditor(messageNode) {
+async function waitForSourceEditor(messageNode) {
   return waitUntil(() => {
     return !!messageNode.querySelector(
       "#response-panel .editor-row-container .CodeMirror");
   });
-} */
+}
diff --git a/devtools/client/webconsole/new-console-output/test/mochitest/head.js b/devtools/client/webconsole/new-console-output/test/mochitest/head.js
index c6c075156f8e..fc9063232246 100644
--- a/devtools/client/webconsole/new-console-output/test/mochitest/head.js
+++ b/devtools/client/webconsole/new-console-output/test/mochitest/head.js
@@ -259,5 +259,6 @@ function* checkClickOnNode(hud, toolbox, frameLinkNode) {
  * Returns true if the give node is currently focused.
  */
 function hasFocus(node) {
-  return node.ownerDocument.activeElement == node;
+  return node.ownerDocument.activeElement == node
+    && node.ownerDocument.hasFocus();
 }
diff --git a/devtools/client/webconsole/new-console-output/test/mochitest/test-bug-869003-iframe.html b/devtools/client/webconsole/new-console-output/test/mochitest/test-bug-869003-iframe.html
index 5a29728e574d..90b1e0ea5800 100644
--- a/devtools/client/webconsole/new-console-output/test/mochitest/test-bug-869003-iframe.html
+++ b/devtools/client/webconsole/new-console-output/test/mochitest/test-bug-869003-iframe.html
@@ -9,7 +9,8 @@
       window.onload = function testConsoleLogging()
       {
         var o = { hello: "world!", bug: 869003 };
-        console.log("foobar", o);
+        var f = Object.assign(function func(arg){}, o);
+        console.log("foobar", o, f);
       };
     // --></script>
   </head>
diff --git a/devtools/client/webconsole/new-console-output/test/store/release-actors.test.js b/devtools/client/webconsole/new-console-output/test/store/release-actors.test.js
index 0c2732f7dd0c..722c2b0b4de6 100644
--- a/devtools/client/webconsole/new-console-output/test/store/release-actors.test.js
+++ b/devtools/client/webconsole/new-console-output/test/store/release-actors.test.js
@@ -42,19 +42,25 @@ describe("Release actor enhancer:", () => {
       const firstMessage = messages.first();
       const firstMessageActor = firstMessage.parameters[1].actor;
 
+      // Add an evaluation result message (see Bug 1408321).
+      const evaluationResultPacket = stubPackets.get("new Date(0)");
+      dispatch(actions.messageAdd(evaluationResultPacket));
+      const secondMessageActor = evaluationResultPacket.result.actor;
+
       const logCount = logLimit + 1;
       const packet = clonePacket(stubPackets.get(
         "console.assert(false, {message: 'foobar'})"));
-      const secondMessageActor = packet.message.arguments[0].actor;
+      const thirdMessageActor = packet.message.arguments[0].actor;
 
       for (let i = 1; i <= logCount; i++) {
         packet.message.arguments.push(`message num ${i}`);
         dispatch(actions.messageAdd(packet));
       }
 
-      expect(releasedActors.length).toBe(2);
+      expect(releasedActors.length).toBe(3);
       expect(releasedActors).toInclude(firstMessageActor);
       expect(releasedActors).toInclude(secondMessageActor);
+      expect(releasedActors).toInclude(thirdMessageActor);
     });
 
     it("properly releases backend actors after clear", () => {
@@ -80,11 +86,24 @@ describe("Release actor enhancer:", () => {
       const secondMessageActor = packet.message.arguments[0].actor;
       dispatch(actions.messageAdd(packet));
 
+      // Add an evaluation result message (see Bug 1408321).
+      const evaluationResultPacket = stubPackets.get("new Date(0)");
+      dispatch(actions.messageAdd(evaluationResultPacket));
+      const thirdMessageActor = evaluationResultPacket.result.actor;
+
+      // Add a message with a long string messageText property.
+      const longStringPacket = stubPackets.get("TypeError longString message");
+      dispatch(actions.messageAdd(longStringPacket));
+      const fourthMessageActor = longStringPacket.pageError.errorMessage.actor;
+
+      // Kick-off the actor release.
       dispatch(actions.messagesClear());
 
-      expect(releasedActors.length).toBe(2);
+      expect(releasedActors.length).toBe(4);
       expect(releasedActors).toInclude(firstMessageActor);
       expect(releasedActors).toInclude(secondMessageActor);
+      expect(releasedActors).toInclude(thirdMessageActor);
+      expect(releasedActors).toInclude(fourthMessageActor);
     });
   });
 });
diff --git a/devtools/client/webconsole/new-console-output/utils/messages.js b/devtools/client/webconsole/new-console-output/utils/messages.js
index 0822bd5556a4..37c7ce44a836 100644
--- a/devtools/client/webconsole/new-console-output/utils/messages.js
+++ b/devtools/client/webconsole/new-console-output/utils/messages.js
@@ -252,7 +252,7 @@ function transformEvaluationResultPacket(packet) {
     notes,
   } = packet;
 
-  let parameters = helperResult && helperResult.object
+  const parameter = helperResult && helperResult.object
     ? helperResult.object
     : result;
 
@@ -263,7 +263,7 @@ function transformEvaluationResultPacket(packet) {
     helperType: helperResult ? helperResult.type : null,
     level,
     messageText,
-    parameters,
+    parameters: [parameter],
     exceptionDocURL,
     frame,
     timeStamp,
diff --git a/devtools/client/webconsole/test/browser_bug_869003_inspect_cross_domain_object.js b/devtools/client/webconsole/test/browser_bug_869003_inspect_cross_domain_object.js
index 685148fc7155..d6f4d1ff2ee3 100644
--- a/devtools/client/webconsole/test/browser_bug_869003_inspect_cross_domain_object.js
+++ b/devtools/client/webconsole/test/browser_bug_869003_inspect_cross_domain_object.js
@@ -39,10 +39,22 @@ add_task(function* () {
 
   let body = msg.querySelector(".message-body");
   ok(body, "message body");
-
-  let clickable = result.clickableElements[0];
-  ok(clickable, "clickable object found");
   ok(body.textContent.includes('{ hello: "world!",'), "message text check");
+  ok(body.textContent.includes('function func()'), "message text check");
+
+  yield testClickable(result.clickableElements[0], [
+    { name: "hello", value: "world!" },
+    { name: "bug", value: 869003 },
+  ], hud);
+  yield testClickable(result.clickableElements[1], [
+    { name: "hello", value: "world!" },
+    { name: "name", value: "func" },
+    { name: "length", value: 1 },
+  ], hud);
+});
+
+function* testClickable(clickable, props, hud) {
+  ok(clickable, "clickable object found");
 
   executeSoon(() => {
     EventUtils.synthesizeMouse(clickable, 2, 2, {}, hud.iframeWindow);
@@ -52,13 +64,9 @@ add_task(function* () {
   ok(aVar, "variables view fetched");
   ok(aVar._variablesView, "variables view object");
 
-  [result] = yield findVariableViewProperties(aVar, [
-    { name: "hello", value: "world!" },
-    { name: "bug", value: 869003 },
-  ], { webconsole: hud });
-
+  let [result] = yield findVariableViewProperties(aVar, props, { webconsole: hud });
   let prop = result.matchedProp;
-  ok(prop, "matched the |hello| property in the variables view");
+  ok(prop, "matched the |" + props[0].name + "| property in the variables view");
 
   // Check that property value updates work.
   aVar = yield updateVariablesViewProperty({
@@ -70,8 +78,6 @@ add_task(function* () {
 
   info("onFetchAfterUpdate");
 
-  yield findVariableViewProperties(aVar, [
-    { name: "hello", value: "omgtest" },
-    { name: "bug", value: 869003 },
-  ], { webconsole: hud });
-});
+  props[0].value = "omgtest";
+  yield findVariableViewProperties(aVar, props, { webconsole: hud });
+}
diff --git a/devtools/client/webconsole/test/test-bug-869003-iframe.html b/devtools/client/webconsole/test/test-bug-869003-iframe.html
index 5a29728e574d..90b1e0ea5800 100644
--- a/devtools/client/webconsole/test/test-bug-869003-iframe.html
+++ b/devtools/client/webconsole/test/test-bug-869003-iframe.html
@@ -9,7 +9,8 @@
       window.onload = function testConsoleLogging()
       {
         var o = { hello: "world!", bug: 869003 };
-        console.log("foobar", o);
+        var f = Object.assign(function func(arg){}, o);
+        console.log("foobar", o, f);
       };
     // --></script>
   </head>
diff --git a/devtools/client/webconsole/webconsole.js b/devtools/client/webconsole/webconsole.js
index 9b2ba885e7e1..f87c79e01a0a 100644
--- a/devtools/client/webconsole/webconsole.js
+++ b/devtools/client/webconsole/webconsole.js
@@ -1849,14 +1849,11 @@ WebConsoleFrame.prototype = {
   openNetworkPanel: function (requestId) {
     let toolbox = gDevTools.getToolbox(this.owner.target);
     // The browser console doesn't have a toolbox.
-    if (!toolbox) {
-      return;
+    if (toolbox) {
+      return toolbox.selectTool("netmonitor").then(panel => {
+        return panel.panelWin.Netmonitor.inspectRequest(requestId);
+      });
     }
-    return toolbox.selectTool("netmonitor").then(panel => {
-      let { inspectRequest } = panel.panelWin.windowRequire(
-        "devtools/client/netmonitor/src/connector/index");
-      return inspectRequest(requestId);
-    });
   },
 
   /**
diff --git a/devtools/server/actors/styles.js b/devtools/server/actors/styles.js
index 04c6977cba51..e2fca08d311a 100644
--- a/devtools/server/actors/styles.js
+++ b/devtools/server/actors/styles.js
@@ -1111,8 +1111,14 @@ var StyleRuleActor = protocol.ActorClassWithSpec(styleRuleSpec, {
       let declarations = parseNamedDeclarations(isCssPropertyKnown,
                                                 form.authoredText || form.cssText,
                                                 true);
+
+      // We need to grab CSS from the window, since calling supports() on the
+      // one from the current global will fail due to not being an HTML global.
+      let CSS = this.pageStyle.inspector.tabActor.window.CSS;
       form.declarations = declarations.map(decl => {
-        decl.isValid = DOMUtils.cssPropertyIsValid(decl.name, decl.value);
+        // Use the 1-arg CSS.supports() call so that we also accept !important
+        // in the value.
+        decl.isValid = CSS.supports(`${decl.name}:${decl.value}`);
         return decl;
       });
     }
diff --git a/devtools/server/actors/stylesheets.js b/devtools/server/actors/stylesheets.js
index 8b518709391c..a6cd469195be 100644
--- a/devtools/server/actors/stylesheets.js
+++ b/devtools/server/actors/stylesheets.js
@@ -12,9 +12,8 @@ const {Task} = require("devtools/shared/task");
 const protocol = require("devtools/shared/protocol");
 const {LongStringActor} = require("devtools/server/actors/string");
 const {fetch} = require("devtools/shared/DevToolsUtils");
-const {originalSourceSpec, mediaRuleSpec, styleSheetSpec,
+const {mediaRuleSpec, styleSheetSpec,
        styleSheetsSpec} = require("devtools/shared/specs/stylesheets");
-const {SourceMapConsumer} = require("source-map");
 const {
   addPseudoClassLock, removePseudoClassLock } = require("devtools/server/actors/highlighters/utils/markup");
 
@@ -58,64 +57,6 @@ exports.UPDATE_GENERAL = UPDATE_GENERAL;
 // edited text to be collected.
 let modifiedStyleSheets = new WeakMap();
 
-/**
- * Actor representing an original source of a style sheet that was specified
- * in a source map.
- */
-var OriginalSourceActor = protocol.ActorClassWithSpec(originalSourceSpec, {
-  initialize: function (url, sourceMap, parentActor) {
-    protocol.Actor.prototype.initialize.call(this, null);
-
-    this.url = url;
-    this.sourceMap = sourceMap;
-    this.parentActor = parentActor;
-    this.conn = this.parentActor.conn;
-
-    this.text = null;
-  },
-
-  form: function () {
-    return {
-      actor: this.actorID, // actorID is set when it's added to a pool
-      url: this.url,
-      relatedStyleSheet: this.parentActor.form()
-    };
-  },
-
-  _getText: function () {
-    if (this.text) {
-      return promise.resolve(this.text);
-    }
-    let content = this.sourceMap.sourceContentFor(this.url);
-    if (content) {
-      this.text = content;
-      return promise.resolve(content);
-    }
-    let options = {
-      // Make sure to use TYPE_OTHER - we are not fetching necessarily
-      // even fetching a style sheet, and anyway we're not planning to
-      // use it as a style sheet per se but rather just for its text;
-      // and this avoids problems with X-Content-Type-Options:
-      // nosniff.  See bug 1330383.
-      policy: Ci.nsIContentPolicy.TYPE_OTHER,
-      window: this.window
-    };
-    return fetch(this.url, options).then(({content: text}) => {
-      this.text = text;
-      return text;
-    });
-  },
-
-  /**
-   * Protocol method to get the text of this source.
-   */
-  getText: function () {
-    return this._getText().then((text) => {
-      return new LongStringActor(this.conn, text || "");
-    });
-  }
-});
-
 /**
  * A MediaRuleActor lives on the server and provides access to properties
  * of a DOM @media rule and emits events when it changes.
@@ -191,9 +132,6 @@ var MediaRuleActor = protocol.ActorClassWithSpec(mediaRuleSpec, {
  * A StyleSheetActor represents a stylesheet on the server.
  */
 var StyleSheetActor = protocol.ActorClassWithSpec(styleSheetSpec, {
-  /* List of original sources that generated this stylesheet */
-  _originalSources: null,
-
   toString: function () {
     return "[StyleSheetActor " + this.actorID + "]";
   },
@@ -499,145 +437,6 @@ var StyleSheetActor = protocol.ActorClassWithSpec(styleSheetSpec, {
     return result;
   }),
 
-  /**
-   * Protocol method to get the original source (actors) for this
-   * stylesheet if it has uses source maps.
-   */
-  getOriginalSources: function () {
-    if (this._originalSources) {
-      return promise.resolve(this._originalSources);
-    }
-    return this._fetchOriginalSources();
-  },
-
-  /**
-   * Fetch the original sources (actors) for this style sheet using its
-   * source map. If they've already been fetched, returns cached array.
-   *
-   * @return {Promise}
-   *         Promise that resolves with an array of OriginalSourceActors
-   */
-  _fetchOriginalSources: function () {
-    this._clearOriginalSources();
-    this._originalSources = [];
-
-    return this.getSourceMap().then((sourceMap) => {
-      if (!sourceMap) {
-        return null;
-      }
-      for (let url of sourceMap.sources) {
-        let actor = new OriginalSourceActor(url, sourceMap, this);
-
-        this.manage(actor);
-        this._originalSources.push(actor);
-      }
-      return this._originalSources;
-    });
-  },
-
-  /**
-   * Get the SourceMapConsumer for this stylesheet's source map, if
-   * it exists. Saves the consumer for later queries.
-   *
-   * @return {Promise}
-   *         A promise that resolves with a SourceMapConsumer, or null.
-   */
-  getSourceMap: function () {
-    if (this._sourceMap) {
-      return this._sourceMap;
-    }
-    return this._fetchSourceMap();
-  },
-
-  /**
-   * Fetch the source map for this stylesheet.
-   *
-   * @return {Promise}
-   *         A promise that resolves with a SourceMapConsumer, or null.
-   */
-  _fetchSourceMap: function () {
-    let deferred = defer();
-
-    let url = this.rawSheet.sourceMapURL;
-    if (!url) {
-      // no source map for this stylesheet
-      deferred.resolve(null);
-      return deferred.promise;
-    }
-
-    url = normalize(url, this.safeHref);
-    let options = {
-      loadFromCache: false,
-      policy: Ci.nsIContentPolicy.TYPE_INTERNAL_STYLESHEET,
-      window: this.window
-    };
-
-    let map = fetch(url, options).then(({content}) => {
-      // Fetching the source map might have failed with a 404 or other. When
-      // this happens, SourceMapConsumer may fail with a JSON.parse error.
-      let consumer;
-      try {
-        consumer = new SourceMapConsumer(content,
-                                         this._getSourceMapRoot(url, this.safeHref));
-      } catch (e) {
-        deferred.reject(new Error(
-          `Source map at ${url} not found or invalid`));
-        return null;
-      }
-      this._sourceMap = promise.resolve(consumer);
-
-      deferred.resolve(consumer);
-      return consumer;
-    }, deferred.reject);
-
-    this._sourceMap = map;
-
-    return deferred.promise;
-  },
-
-  /**
-   * Clear and unmanage the original source actors for this stylesheet.
-   */
-  _clearOriginalSources: function () {
-    for (let actor in this._originalSources) {
-      this.unmanage(actor);
-    }
-    this._originalSources = null;
-  },
-
-  /**
-   * Compute the URL to pass to the SourceMapConsumer constructor as
-   * the "source map's URL".
-   */
-  _getSourceMapRoot: function (absSourceMapURL, scriptURL) {
-    // Pass in the source map URL; except if it is a data: or blob:
-    // URL, fall back to using the source's URL, if possible.
-    if (scriptURL && (absSourceMapURL.startsWith("data:") ||
-                      absSourceMapURL.startsWith("blob:"))) {
-      return scriptURL;
-    }
-    return absSourceMapURL;
-  },
-
-  /**
-   * Protocol method that gets the location in the original source of a
-   * line, column pair in this stylesheet, if its source mapped, otherwise
-   * a promise of the same location.
-   */
-  getOriginalLocation: function (line, column) {
-    return this.getSourceMap().then((sourceMap) => {
-      if (sourceMap) {
-        return sourceMap.originalPositionFor({ line: line, column: column });
-      }
-      return {
-        fromSourceMap: false,
-        source: this.href,
-        line: line,
-        column: column
-      };
-    });
-  },
-
   /**
    * Protocol method to get the media rules for the stylesheet.
    */
@@ -1043,15 +842,3 @@ var StyleSheetsActor = protocol.ActorClassWithSpec(styleSheetsSpec, {
 });
 
 exports.StyleSheetsActor = StyleSheetsActor;
-
-/**
- * Normalize multiple relative paths towards the base paths on the right.
- */
-function normalize(...urls) {
-  let base = Services.io.newURI(urls.pop());
-  let url;
-  while ((url = urls.pop())) {
-    base = Services.io.newURI(url, null, base);
-  }
-  return base.spec;
-}
diff --git a/devtools/server/actors/webconsole.js b/devtools/server/actors/webconsole.js
index 23e90623e1e0..f95d6a7fd01b 100644
--- a/devtools/server/actors/webconsole.js
+++ b/devtools/server/actors/webconsole.js
@@ -443,7 +443,8 @@ WebConsoleActor.prototype =
    *         Debuggee value for |value|.
    */
   makeDebuggeeValue: function (value, useObjectGlobal) {
-    if (useObjectGlobal && typeof value == "object") {
+    let isObject = Object(value) === value;
+    if (useObjectGlobal && isObject) {
       try {
         let global = Cu.getGlobalForObject(value);
         let dbgGlobal = this.dbg.makeGlobalObjectReference(global);
diff --git a/devtools/shared/fronts/stylesheets.js b/devtools/shared/fronts/stylesheets.js
index 22c960b64603..bbb5db69773f 100644
--- a/devtools/shared/fronts/stylesheets.js
+++ b/devtools/shared/fronts/stylesheets.js
@@ -5,7 +5,6 @@
 
 const { Front, FrontClassWithSpec } = require("devtools/shared/protocol");
 const {
-  originalSourceSpec,
   mediaRuleSpec,
   styleSheetSpec,
   styleSheetsSpec
@@ -18,35 +17,6 @@ loader.lazyRequireGetter(this, "getIndentationFromPrefs",
 loader.lazyRequireGetter(this, "getIndentationFromString",
   "devtools/shared/indentation", true);
 
-/**
- * The client-side counterpart for an OriginalSourceActor.
- */
-const OriginalSourceFront = FrontClassWithSpec(originalSourceSpec, {
-  initialize: function (client, form) {
-    Front.prototype.initialize.call(this, client, form);
-
-    this.isOriginalSource = true;
-  },
-
-  form: function (form, detail) {
-    if (detail === "actorid") {
-      this.actorID = form;
-      return;
-    }
-    this.actorID = form.actor;
-    this._form = form;
-  },
-
-  get href() {
-    return this._form.url;
-  },
-  get url() {
-    return this._form.url;
-  }
-});
-
-exports.OriginalSourceFront = OriginalSourceFront;
-
 /**
  * Corresponding client-side front for a MediaRuleActor.
  */
@@ -143,6 +113,9 @@ const StyleSheetFront = FrontClassWithSpec(styleSheetSpec, {
   get ruleCount() {
     return this._form.ruleCount;
   },
+  get sourceMapURL() {
+    return this._form.sourceMapURL;
+  },
 
   /**
    * Get the indentation to use for edits to this style sheet.
diff --git a/devtools/shared/specs/index.js b/devtools/shared/specs/index.js
index 8a85162b3a3d..0a81a0da9bce 100644
--- a/devtools/shared/specs/index.js
+++ b/devtools/shared/specs/index.js
@@ -190,7 +190,7 @@ const Types = exports.__TypesForTests = [
     front: "devtools/shared/fronts/styles",
   },
   {
-    types: ["originalsource", "mediarule", "stylesheet", "stylesheets"],
+    types: ["mediarule", "stylesheet", "stylesheets"],
     spec: "devtools/shared/specs/stylesheets",
     front: "devtools/shared/fronts/stylesheets",
   },
diff --git a/devtools/shared/specs/stylesheets.js b/devtools/shared/specs/stylesheets.js
index fc75281f85dc..8ae738a150bc 100644
--- a/devtools/shared/specs/stylesheets.js
+++ b/devtools/shared/specs/stylesheets.js
@@ -10,20 +10,6 @@ const {
   types
 } = require("devtools/shared/protocol");
 
-const originalSourceSpec = generateActorSpec({
-  typeName: "originalsource",
-
-  methods: {
-    getText: {
-      response: {
-        text: RetVal("longstring")
-      }
-    }
-  }
-});
-
-exports.originalSourceSpec = originalSourceSpec;
-
 const mediaRuleSpec = generateActorSpec({
   typeName: "mediarule",
 
@@ -68,23 +54,6 @@ const styleSheetSpec = generateActorSpec({
         text: RetVal("longstring")
       }
     },
-    getOriginalSources: {
-      request: {},
-      response: {
-        originalSources: RetVal("nullable:array:originalsource")
-      }
-    },
-    getOriginalLocation: {
-      request: {
-        line: Arg(0, "number"),
-        column: Arg(1, "number")
-      },
-      response: RetVal(types.addDictType("originallocationresponse", {
-        source: "string",
-        line: "number",
-        column: "number"
-      }))
-    },
     getMediaRules: {
       request: {},
       response: {
diff --git a/docshell/base/crashtests/crashtests.list b/docshell/base/crashtests/crashtests.list
index 600f7a3dd0ca..b5926649c5d8 100644
--- a/docshell/base/crashtests/crashtests.list
+++ b/docshell/base/crashtests/crashtests.list
@@ -11,7 +11,7 @@ load 500328-1.html
 load 514779-1.xhtml
 load 614499-1.html
 load 678872-1.html
-skip-if(Android) skip-if(webrender&&debug) pref(dom.disable_open_during_load,false) load 914521.html
+skip-if(Android) pref(dom.disable_open_during_load,false) load 914521.html
 pref(browser.send_pings,true) load 1257730-1.html
 load 1331295.html
 load 1341657.html
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index 4e70ebaa533f..f2a6fec44cff 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -13692,10 +13692,8 @@ nsIDocument::UpdateStyleBackendType()
     // able to use XUL by default, and the back door to enable XUL is
     // mostly just for testing, which means they don't matter, and we
     // shouldn't respect them at the same time.
-    // Note that, since tests can have XUL support, we still need to
-    // explicitly exclude XUL documents here.
     if (!nsContentUtils::IsSystemPrincipal(NodePrincipal()) &&
-        !IsXULDocument() && !ShouldUseGeckoBackend(mDocumentURI) &&
+        !ShouldUseGeckoBackend(mDocumentURI) &&
         !nsLayoutUtils::IsInStyloBlocklist(NodePrincipal())) {
       mStyleBackendType = StyleBackendType::Servo;
     }
diff --git a/dom/base/nsGkAtomList.h b/dom/base/nsGkAtomList.h
index 78c16d515ee5..cf43390eef2a 100644
--- a/dom/base/nsGkAtomList.h
+++ b/dom/base/nsGkAtomList.h
@@ -2271,7 +2271,6 @@ GK_ATOM(windows_glass, "windows-glass")
 GK_ATOM(touch_enabled, "touch-enabled")
 GK_ATOM(menubar_drag, "menubar-drag")
 GK_ATOM(swipe_animation_enabled, "swipe-animation-enabled")
-GK_ATOM(physical_home_button, "physical-home-button")
 
 // windows theme selector metrics
 GK_ATOM(windows_classic, "windows-classic")
@@ -2306,7 +2305,6 @@ GK_ATOM(_moz_device_pixel_ratio, "-moz-device-pixel-ratio")
 GK_ATOM(_moz_device_orientation, "-moz-device-orientation")
 GK_ATOM(_moz_is_resource_document, "-moz-is-resource-document")
 GK_ATOM(_moz_swipe_animation_enabled, "-moz-swipe-animation-enabled")
-GK_ATOM(_moz_physical_home_button, "-moz-physical-home-button")
 
 // application commands
 GK_ATOM(Back, "Back")
diff --git a/dom/canvas/CanvasRenderingContext2D.cpp b/dom/canvas/CanvasRenderingContext2D.cpp
index 0b7cfc26a960..414e56e64b5b 100644
--- a/dom/canvas/CanvasRenderingContext2D.cpp
+++ b/dom/canvas/CanvasRenderingContext2D.cpp
@@ -127,6 +127,7 @@
 #include "mozilla/StyleSetHandle.h"
 #include "mozilla/StyleSetHandleInlines.h"
 #include "mozilla/layers/CanvasClient.h"
+#include "mozilla/ServoCSSParser.h"
 
 #undef free // apparently defined by some windows header, clashing with a free()
             // method in SkTypes.h
@@ -745,17 +746,28 @@ CanvasGradient::AddColorStop(float aOffset, const nsAString& aColorstr, ErrorRes
     return;
   }
 
-  nsCSSValue value;
-  nsCSSParser parser;
-  if (!parser.ParseColorString(aColorstr, nullptr, 0, value)) {
-    aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
-    return;
+  nscolor color;
+  bool ok;
+
+  nsIPresShell* shell = mContext ? mContext->GetPresShell() : nullptr;
+  ServoStyleSet* servoStyleSet = shell && shell->StyleSet()
+    ? shell->StyleSet()->GetAsServo()
+    : nullptr;
+
+  if (servoStyleSet) {
+    ok = ServoCSSParser::ComputeColor(servoStyleSet, NS_RGB(0, 0, 0), aColorstr,
+                                      &color);
+  } else {
+    nsCSSValue value;
+    nsCSSParser parser;
+
+    nsPresContext* presContext = shell ? shell->GetPresContext() : nullptr;
+
+    ok = parser.ParseColorString(aColorstr, nullptr, 0, value) &&
+         nsRuleNode::ComputeColor(value, presContext, nullptr, color);
   }
 
-  nscolor color;
-  nsCOMPtr<nsIPresShell> presShell = mContext ? mContext->GetPresShell() : nullptr;
-  if (!nsRuleNode::ComputeColor(value, presShell ? presShell->GetPresContext() : nullptr,
-                                nullptr, color)) {
+  if (!ok) {
     aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
     return;
   }
diff --git a/dom/canvas/DocumentRendererChild.cpp b/dom/canvas/DocumentRendererChild.cpp
index edfc4746a72c..2668a5071d98 100644
--- a/dom/canvas/DocumentRendererChild.cpp
+++ b/dom/canvas/DocumentRendererChild.cpp
@@ -25,6 +25,7 @@
 #include "nsCSSValue.h"
 #include "nsRuleNode.h"
 #include "mozilla/gfx/Matrix.h"
+#include "mozilla/ServoCSSParser.h"
 
 using namespace mozilla;
 using namespace mozilla::gfx;
@@ -59,15 +60,24 @@ DocumentRendererChild::RenderDocument(nsPIDOMWindowOuter* window,
     if (!presContext)
         return false;
 
-    nsCSSParser parser;
-    nsCSSValue bgColorValue;
-    if (!parser.ParseColorString(aBGColor, nullptr, 0, bgColorValue)) {
-        return false;
-    }
-
     nscolor bgColor;
-    if (!nsRuleNode::ComputeColor(bgColorValue, presContext, nullptr, bgColor)) {
+
+    ServoStyleSet* servoStyleSet = presContext->StyleSet()
+      ? presContext->StyleSet()->GetAsServo()
+      : nullptr;
+
+    if (servoStyleSet) {
+      if (!ServoCSSParser::ComputeColor(servoStyleSet, NS_RGB(0, 0, 0),
+                                        aBGColor, &bgColor)) {
         return false;
+      }
+    } else {
+      nsCSSParser parser;
+      nsCSSValue bgColorValue;
+      if (!parser.ParseColorString(aBGColor, nullptr, 0, bgColorValue) ||
+          !nsRuleNode::ComputeColor(bgColorValue, presContext, nullptr, bgColor)) {
+        return false;
+      }
     }
 
     // Draw directly into the output array.
diff --git a/dom/credentialmanagement/CredentialsContainer.cpp b/dom/credentialmanagement/CredentialsContainer.cpp
index c8b2afe35079..b0b7da6dfc58 100644
--- a/dom/credentialmanagement/CredentialsContainer.cpp
+++ b/dom/credentialmanagement/CredentialsContainer.cpp
@@ -48,5 +48,12 @@ CredentialsContainer::Create(const CredentialCreationOptions& aOptions)
   return mgr->MakeCredential(mParent, aOptions.mPublicKey);
 }
 
+already_AddRefed<Promise>
+CredentialsContainer::Store(const Credential& aCredential)
+{
+  RefPtr<WebAuthnManager> mgr = WebAuthnManager::GetOrCreate();
+  return mgr->Store(mParent, aCredential);
+}
+
 } // namespace dom
 } // namespace mozilla
diff --git a/dom/credentialmanagement/CredentialsContainer.h b/dom/credentialmanagement/CredentialsContainer.h
index 7816d948247f..187ac5c12982 100644
--- a/dom/credentialmanagement/CredentialsContainer.h
+++ b/dom/credentialmanagement/CredentialsContainer.h
@@ -34,6 +34,8 @@ public:
   Get(const CredentialRequestOptions& aOptions);
   already_AddRefed<Promise>
   Create(const CredentialCreationOptions& aOptions);
+  already_AddRefed<Promise>
+  Store(const Credential& aCredential);
 
 private:
   ~CredentialsContainer();
diff --git a/dom/html/HTMLMediaElement.cpp b/dom/html/HTMLMediaElement.cpp
index 5f5c104a0e90..222225b733a4 100644
--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -14,6 +14,7 @@
 #include "mozilla/AsyncEventDispatcher.h"
 #include "mozilla/dom/MediaEncryptedEvent.h"
 #include "mozilla/EMEUtils.h"
+#include "mozilla/Sprintf.h"
 
 #include "base/basictypes.h"
 #include "nsIDOMHTMLMediaElement.h"
@@ -5011,7 +5012,7 @@ nsresult HTMLMediaElement::InitializeDecoderForChannel(nsIChannel* aChannel,
 #endif
 
   RefPtr<ChannelMediaDecoder> decoder =
-    DecoderTraits::CreateDecoder(decoderInit, &diagnostics);
+    ChannelMediaDecoder::Create(decoderInit, &diagnostics);
   if (!decoder) {
     reportCanPlay(false);
     return NS_ERROR_FAILURE;
diff --git a/dom/media/ChannelMediaDecoder.cpp b/dom/media/ChannelMediaDecoder.cpp
index 3ddf1ea5e285..761f687fa8bb 100644
--- a/dom/media/ChannelMediaDecoder.cpp
+++ b/dom/media/ChannelMediaDecoder.cpp
@@ -173,6 +173,28 @@ ChannelMediaDecoder::ChannelMediaDecoder(MediaDecoderInit& aInit)
   mWatchManager.Watch(mLogicallySeeking, &ChannelMediaDecoder::SeekingChanged);
 }
 
+/* static */
+already_AddRefed<ChannelMediaDecoder>
+ChannelMediaDecoder::Create(MediaDecoderInit& aInit,
+                            DecoderDoctorDiagnostics* aDiagnostics)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  RefPtr<ChannelMediaDecoder> decoder;
+
+  const MediaContainerType& type = aInit.mContainerType;
+  if (DecoderTraits::IsSupportedType(type)) {
+    decoder = new ChannelMediaDecoder(aInit);
+    return decoder.forget();
+  }
+
+  if (DecoderTraits::IsHttpLiveStreamingType(type)) {
+    // We don't have an HLS decoder.
+    Telemetry::Accumulate(Telemetry::MEDIA_HLS_DECODER_SUCCESS, false);
+  }
+
+  return nullptr;
+}
+
 bool
 ChannelMediaDecoder::CanClone()
 {
diff --git a/dom/media/ChannelMediaDecoder.h b/dom/media/ChannelMediaDecoder.h
index ee124dc7ed06..3117be10e150 100644
--- a/dom/media/ChannelMediaDecoder.h
+++ b/dom/media/ChannelMediaDecoder.h
@@ -66,9 +66,17 @@ protected:
   RefPtr<ResourceCallback> mResourceCallback;
   RefPtr<BaseMediaResource> mResource;
 
-public:
   explicit ChannelMediaDecoder(MediaDecoderInit& aInit);
 
+public:
+
+  // Create a decoder for the given aType. Returns null if we were unable
+  // to create the decoder, for example because the requested MIME type in
+  // the init struct was unsupported.
+  static already_AddRefed<ChannelMediaDecoder> Create(
+    MediaDecoderInit& aInit,
+    DecoderDoctorDiagnostics* aDiagnostics);
+
   void Shutdown() override;
 
   bool CanClone();
diff --git a/dom/media/DecoderTraits.cpp b/dom/media/DecoderTraits.cpp
index 1103a2d07ddb..69f8d22fd011 100644
--- a/dom/media/DecoderTraits.cpp
+++ b/dom/media/DecoderTraits.cpp
@@ -4,7 +4,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#include "ChannelMediaDecoder.h"
 #include "DecoderTraits.h"
 #include "MediaContainerType.h"
 #include "nsMimeTypes.h"
@@ -224,37 +223,6 @@ bool DecoderTraits::ShouldHandleMediaType(const char* aMIMEType,
   return CanHandleMediaType(*containerType, aDiagnostics) != CANPLAY_NO;
 }
 
-// Instantiates but does not initialize decoder.
-static already_AddRefed<ChannelMediaDecoder>
-InstantiateDecoder(MediaDecoderInit& aInit,
-                   DecoderDoctorDiagnostics* aDiagnostics)
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  RefPtr<ChannelMediaDecoder> decoder;
-
-  const MediaContainerType& type = aInit.mContainerType;
-  if (DecoderTraits::IsSupportedType(type)) {
-    decoder = new ChannelMediaDecoder(aInit);
-    return decoder.forget();
-  }
-
-  if (DecoderTraits::IsHttpLiveStreamingType(type)) {
-    // We don't have an HLS decoder.
-    Telemetry::Accumulate(Telemetry::MEDIA_HLS_DECODER_SUCCESS, false);
-  }
-
-  return nullptr;
-}
-
-/* static */
-already_AddRefed<ChannelMediaDecoder>
-DecoderTraits::CreateDecoder(MediaDecoderInit& aInit,
-                             DecoderDoctorDiagnostics* aDiagnostics)
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  return InstantiateDecoder(aInit, aDiagnostics);
-}
-
 /* static */
 MediaFormatReader*
 DecoderTraits::CreateReader(const MediaContainerType& aType,
diff --git a/dom/media/DecoderTraits.h b/dom/media/DecoderTraits.h
index 91046a7aaeb0..4edf831ef8d7 100644
--- a/dom/media/DecoderTraits.h
+++ b/dom/media/DecoderTraits.h
@@ -7,19 +7,14 @@
 #ifndef DecoderTraits_h_
 #define DecoderTraits_h_
 
-#include "nsCOMPtr.h"
 #include "nsStringFwd.h"
 
 namespace mozilla {
 
-class ChannelMediaDecoder;
 class DecoderDoctorDiagnostics;
 class MediaContainerType;
-struct MediaDecoderInit;
 struct MediaFormatReaderInit;
-class MediaDecoderOwner;
 class MediaFormatReader;
-class MediaResource;
 
 enum CanPlayStatus {
   CANPLAY_NO,
@@ -40,12 +35,6 @@ public:
   static bool ShouldHandleMediaType(const char* aMIMEType,
                                     DecoderDoctorDiagnostics* aDiagnostics);
 
-  // Create a decoder for the given aType. Returns null if we
-  // were unable to create the decoder.
-  static already_AddRefed<ChannelMediaDecoder> CreateDecoder(
-    MediaDecoderInit& aInit,
-    DecoderDoctorDiagnostics* aDiagnostics);
-
   // Create a reader for thew given MIME type aType. Returns null
   // if we were unable to create the reader.
   static MediaFormatReader* CreateReader(const MediaContainerType& aType,
diff --git a/dom/media/MediaData.cpp b/dom/media/MediaData.cpp
index a6cb630ddec7..ecc82be11a1b 100644
--- a/dom/media/MediaData.cpp
+++ b/dom/media/MediaData.cpp
@@ -17,6 +17,7 @@
 #include <stdint.h>
 
 #ifdef XP_WIN
+#include "mozilla/WindowsVersion.h"
 #include "mozilla/layers/D3D11YCbCrImage.h"
 #endif
 
@@ -319,7 +320,9 @@ VideoData::CreateAndCopyData(const VideoInfo& aInfo,
   // Currently our decoder only knows how to output to ImageFormat::PLANAR_YCBCR
   // format.
 #if XP_WIN
-  if (!XRE_IsParentProcess() &&
+  // We disable this code path on Windows version earlier of Windows 8 due to
+  // intermittent crashes with old drivers. See bug 1405110.
+  if (IsWin8OrLater() && !XRE_IsParentProcess() &&
       aAllocator && aAllocator->GetCompositorBackendType()
                     == layers::LayersBackend::LAYERS_D3D11) {
     RefPtr<layers::D3D11YCbCrImage> d3d11Image = new layers::D3D11YCbCrImage();
diff --git a/dom/media/MediaDecoder.cpp b/dom/media/MediaDecoder.cpp
index 46dd8d9e7182..06401a97ef59 100644
--- a/dom/media/MediaDecoder.cpp
+++ b/dom/media/MediaDecoder.cpp
@@ -275,12 +275,6 @@ LazyLogModule gMediaTimerLog("MediaTimer");
 
 constexpr TimeUnit MediaDecoder::DEFAULT_NEXT_FRAME_AVAILABLE_BUFFERED;
 
-void
-MediaDecoder::InitStatics()
-{
-  MOZ_ASSERT(NS_IsMainThread());
-}
-
 NS_IMPL_ISUPPORTS(MediaMemoryTracker, nsIMemoryReporter)
 
 void
diff --git a/dom/media/MediaDecoder.h b/dom/media/MediaDecoder.h
index c5c6455a5692..eb63fc11d19d 100644
--- a/dom/media/MediaDecoder.h
+++ b/dom/media/MediaDecoder.h
@@ -23,7 +23,6 @@
 #include "mozilla/ReentrantMonitor.h"
 #include "mozilla/StateMirroring.h"
 #include "mozilla/StateWatching.h"
-#include "necko-config.h"
 #include "nsAutoPtr.h"
 #include "nsCOMPtr.h"
 #include "nsIObserver.h"
@@ -100,9 +99,6 @@ public:
     PLAY_STATE_SHUTDOWN
   };
 
-  // Must be called exactly once, on the main thread, during startup.
-  static void InitStatics();
-
   explicit MediaDecoder(MediaDecoderInit& aInit);
 
   // Returns the container content type of the resource.
diff --git a/dom/media/MediaFormatReader.cpp b/dom/media/MediaFormatReader.cpp
index 1a13cc1b6a02..dac2ca5ec950 100644
--- a/dom/media/MediaFormatReader.cpp
+++ b/dom/media/MediaFormatReader.cpp
@@ -91,6 +91,7 @@ public:
     MOZ_ASSERT(aMediaDataDecoderID);
     MOZ_ASSERT(!aGPUCrashTime.IsNull());
     MOZ_ASSERT(!aErrorNotifiedTime.IsNull());
+    StaticMutexAutoLock lock(sGPUCrashMapMutex);
     auto it = sGPUCrashDataMap.find(aMediaDecoderOwnerID);
     if (it == sGPUCrashDataMap.end()) {
       sGPUCrashDataMap.insert(std::make_pair(aMediaDecoderOwnerID,
@@ -106,6 +107,7 @@ public:
   {
     MOZ_ASSERT(aMediaDecoderOwnerID);
     MOZ_ASSERT(aMediaDataDecoderID);
+    StaticMutexAutoLock lock(sGPUCrashMapMutex);
     auto it = sGPUCrashDataMap.find(aMediaDecoderOwnerID);
     if (it != sGPUCrashDataMap.end() &&
         it->second.mMediaDataDecoderID != aMediaDataDecoderID) {
@@ -121,10 +123,12 @@ public:
 
 private:
   static std::map<MediaDecoderOwnerID, GPUCrashData> sGPUCrashDataMap;
+  static StaticMutex sGPUCrashMapMutex;
 };
 
 std::map<MediaDecoderOwnerID, GPUProcessCrashTelemetryLogger::GPUCrashData>
 GPUProcessCrashTelemetryLogger::sGPUCrashDataMap;
+StaticMutex GPUProcessCrashTelemetryLogger::sGPUCrashMapMutex;
 
 /**
  * This is a singleton which controls the number of decoders that can be
diff --git a/dom/media/fake-cdm/cdm-fake.cpp b/dom/media/fake-cdm/cdm-fake.cpp
index 9b5f6579fd97..e74c86074cfd 100644
--- a/dom/media/fake-cdm/cdm-fake.cpp
+++ b/dom/media/fake-cdm/cdm-fake.cpp
@@ -52,6 +52,10 @@ void* CreateCdmInstance(int cdm_interface_version,
                         GetCdmHostFunc get_cdm_host_func,
                         void* user_data)
 {
+  if (cdm_interface_version != cdm::ContentDecryptionModule_8::kVersion) {
+    // Only support CDM version 8 currently.
+    return nullptr;
+  }
   cdm::Host_8* host = static_cast<cdm::Host_8*>(
     get_cdm_host_func(cdm_interface_version, user_data));
   return new FakeDecryptor(host);
diff --git a/dom/media/gmp/ChromiumCDMAdapter.cpp b/dom/media/gmp/ChromiumCDMAdapter.cpp
index 3423ea4b3542..79241a617c8a 100644
--- a/dom/media/gmp/ChromiumCDMAdapter.cpp
+++ b/dom/media/gmp/ChromiumCDMAdapter.cpp
@@ -54,10 +54,11 @@ void*
 ChromiumCdmHost(int aHostInterfaceVersion, void* aUserData)
 {
   GMP_LOG("ChromiumCdmHostFunc(%d, %p)", aHostInterfaceVersion, aUserData);
-  if (aHostInterfaceVersion != cdm::Host_8::kVersion) {
+  if (aHostInterfaceVersion != cdm::Host_8::kVersion &&
+      aHostInterfaceVersion != cdm::Host_9::kVersion) {
     return nullptr;
   }
-  return static_cast<cdm::Host_8*>(aUserData);
+  return aUserData;
 }
 
 #define STRINGIFY(s) _STRINGIFY(s)
@@ -121,7 +122,9 @@ ChromiumCDMAdapter::GMPGetAPI(const char* aAPIName,
           aPluginAPI,
           aDecryptorId,
           this);
-  if (!strcmp(aAPIName, CHROMIUM_CDM_API)) {
+  bool isCDM9 = !strcmp(aAPIName, CHROMIUM_CDM_API);
+  bool isCDM8 = !strcmp(aAPIName, CHROMIUM_CDM_API_BACKWARD_COMPAT);
+  if (isCDM8 || isCDM9) {
     auto create = reinterpret_cast<decltype(::CreateCdmInstance)*>(
       PR_FindFunctionSymbol(mLib, "CreateCdmInstance"));
     if (!create) {
@@ -135,23 +138,26 @@ ChromiumCDMAdapter::GMPGetAPI(const char* aAPIName,
       return GMPGenericErr;
     }
 
-    auto cdm = reinterpret_cast<cdm::ContentDecryptionModule_8*>(
-      create(cdm::ContentDecryptionModule_8::kVersion,
+    int version = isCDM8 ? cdm::ContentDecryptionModule_8::kVersion :
+                           cdm::ContentDecryptionModule_9::kVersion;
+    void* cdm =
+      create(version,
              kEMEKeySystemWidevine.get(),
              kEMEKeySystemWidevine.Length(),
              &ChromiumCdmHost,
-             aHostAPI));
+             aHostAPI);
     if (!cdm) {
       GMP_LOG("ChromiumCDMAdapter::GMPGetAPI(%s, 0x%p, 0x%p, %u) this=0x%p "
-              "FAILED to create cdm",
+              "FAILED to create cdm version %d",
               aAPIName,
               aHostAPI,
               aPluginAPI,
               aDecryptorId,
-              this);
+              this,
+              version);
       return GMPGenericErr;
     }
-    GMP_LOG("cdm: 0x%p", cdm);
+    GMP_LOG("cdm: 0x%p, version: %d", cdm, version);
     *aPluginAPI = cdm;
   }
   return *aPluginAPI ? GMPNoErr : GMPNotImplementedErr;
@@ -177,8 +183,10 @@ ChromiumCDMAdapter::Supports(int32_t aModuleVersion,
                              int32_t aHostVersion)
 {
   return aModuleVersion == CDM_MODULE_VERSION &&
-         aInterfaceVersion == cdm::ContentDecryptionModule_8::kVersion &&
-         aHostVersion == cdm::Host_8::kVersion;
+         (aInterfaceVersion == cdm::ContentDecryptionModule_8::kVersion ||
+         aInterfaceVersion == cdm::ContentDecryptionModule_9::kVersion) &&
+         (aHostVersion == cdm::Host_8::kVersion ||
+         aHostVersion == cdm::Host_9::kVersion);
 }
 
 #ifdef XP_WIN
diff --git a/dom/media/gmp/ChromiumCDMChild.cpp b/dom/media/gmp/ChromiumCDMChild.cpp
index fa3428da8001..57074eb791a4 100644
--- a/dom/media/gmp/ChromiumCDMChild.cpp
+++ b/dom/media/gmp/ChromiumCDMChild.cpp
@@ -27,7 +27,7 @@ ChromiumCDMChild::ChromiumCDMChild(GMPContentChild* aPlugin)
 }
 
 void
-ChromiumCDMChild::Init(cdm::ContentDecryptionModule_8* aCDM)
+ChromiumCDMChild::Init(cdm::ContentDecryptionModule_9* aCDM)
 {
   MOZ_ASSERT(IsOnMessageLoopThread());
   mCDM = aCDM;
@@ -222,6 +222,13 @@ ChromiumCDMChild::CallOnMessageLoopThread(const char* const aName,
   }
 }
 
+// cdm::Host_9 interface
+void
+ChromiumCDMChild::OnResolveKeyStatusPromise(uint32_t aPromiseId,
+                                            cdm::KeyStatus aKeyStatus) {
+  //TODO: The callback of GetStatusForPolicy, will implement it in Bug 1404230.
+}
+
 bool
 ChromiumCDMChild::OnResolveNewSessionPromiseInternal(uint32_t aPromiseId,
                                                      const nsCString& aSessionId)
@@ -269,27 +276,68 @@ void ChromiumCDMChild::OnResolvePromise(uint32_t aPromiseId)
                           aPromiseId);
 }
 
+// Align with spec, the Exceptions used by CDM to reject promises .
+// https://w3c.github.io/encrypted-media/#exceptions
+cdm::Exception
+ConvertCDMErrorToCDMException(cdm::Error error) {
+  switch (error) {
+    case cdm::kNotSupportedError:
+      return cdm::Exception::kExceptionNotSupportedError;
+    case cdm::kInvalidStateError:
+      return cdm::Exception::kExceptionInvalidStateError;
+    case cdm::kInvalidAccessError:
+      return cdm::Exception::kExceptionTypeError;
+    case cdm::kQuotaExceededError:
+      return cdm::Exception::kExceptionQuotaExceededError;
+
+    // cdm8 only error
+    case cdm::kUnknownError:
+    case cdm::kClientError:
+    case cdm::kOutputError:
+      break;
+  }
+
+  return cdm::Exception::kExceptionInvalidStateError;
+}
+
+// cdm::Host_8 only interface
 void
 ChromiumCDMChild::OnRejectPromise(uint32_t aPromiseId,
                                   cdm::Error aError,
                                   uint32_t aSystemCode,
                                   const char* aErrorMessage,
                                   uint32_t aErrorMessageSize)
+{
+  OnRejectPromise(aPromiseId,
+                  ConvertCDMErrorToCDMException(aError),
+                  aSystemCode,
+                  aErrorMessage,
+                  aErrorMessageSize);
+}
+
+// cdm::Host_9 interface
+void
+ChromiumCDMChild::OnRejectPromise(uint32_t aPromiseId,
+                                  cdm::Exception aException,
+                                  uint32_t aSystemCode,
+                                  const char* aErrorMessage,
+                                  uint32_t aErrorMessageSize)
 {
   GMP_LOG("ChromiumCDMChild::OnRejectPromise(pid=%" PRIu32 ", err=%" PRIu32
           " code=%" PRIu32 ", msg='%s')",
           aPromiseId,
-          aError,
+          aException,
           aSystemCode,
           aErrorMessage);
   CallOnMessageLoopThread("gmp::ChromiumCDMChild::OnRejectPromise",
                           &ChromiumCDMChild::SendOnRejectPromise,
                           aPromiseId,
-                          static_cast<uint32_t>(aError),
+                          static_cast<uint32_t>(aException),
                           aSystemCode,
                           nsCString(aErrorMessage, aErrorMessageSize));
 }
 
+// cdm::Host_8 only interface
 void
 ChromiumCDMChild::OnSessionMessage(const char* aSessionId,
                                    uint32_t aSessionIdSize,
@@ -298,6 +346,17 @@ ChromiumCDMChild::OnSessionMessage(const char* aSessionId,
                                    uint32_t aMessageSize,
                                    const char* aLegacyDestinationUrl,
                                    uint32_t aLegacyDestinationUrlLength)
+{
+  OnSessionMessage(aSessionId, aSessionIdSize, aMessageType, aMessage, aMessageSize);
+}
+
+// cdm::Host_9 interface
+void
+ChromiumCDMChild::OnSessionMessage(const char* aSessionId,
+                                   uint32_t aSessionIdSize,
+                                   cdm::MessageType aMessageType,
+                                   const char* aMessage,
+                                   uint32_t aMessageSize)
 {
   GMP_LOG("ChromiumCDMChild::OnSessionMessage(sid=%s, type=%" PRIu32
           " size=%" PRIu32 ")",
diff --git a/dom/media/gmp/ChromiumCDMChild.h b/dom/media/gmp/ChromiumCDMChild.h
index d9cd297f1657..625b4de3be52 100644
--- a/dom/media/gmp/ChromiumCDMChild.h
+++ b/dom/media/gmp/ChromiumCDMChild.h
@@ -18,36 +18,40 @@ class GMPContentChild;
 
 class ChromiumCDMChild : public PChromiumCDMChild
                        , public cdm::Host_8
+                       , public cdm::Host_9
 {
 public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ChromiumCDMChild);
 
   explicit ChromiumCDMChild(GMPContentChild* aPlugin);
 
-  void Init(cdm::ContentDecryptionModule_8* aCDM);
+  void Init(cdm::ContentDecryptionModule_9* aCDM);
 
   void TimerExpired(void* aContext);
 
-  // cdm::Host_8
+  // cdm::Host_9 implementation
   cdm::Buffer* Allocate(uint32_t aCapacity) override;
   void SetTimer(int64_t aDelayMs, void* aContext) override;
   cdm::Time GetCurrentWallTime() override;
+  // cdm::Host_9 interface
+  void OnResolveKeyStatusPromise(uint32_t aPromiseId,
+                                 cdm::KeyStatus aKeyStatus) override;
   void OnResolveNewSessionPromise(uint32_t aPromiseId,
                                   const char* aSessionId,
                                   uint32_t aSessionIdSize) override;
   void OnResolvePromise(uint32_t aPromiseId) override;
+  // cdm::Host_9 interface
   void OnRejectPromise(uint32_t aPromiseId,
-                       cdm::Error aError,
+                       cdm::Exception aException,
                        uint32_t aSystemCode,
                        const char* aErrorMessage,
                        uint32_t aErrorMessageSize) override;
+  // cdm::Host_9 interface
   void OnSessionMessage(const char* aSessionId,
                         uint32_t aSessionIdSize,
                         cdm::MessageType aMessageType,
                         const char* aMessage,
-                        uint32_t aMessageSize,
-                        const char* aLegacyDestinationUrl,
-                        uint32_t aLegacyDestinationUrlLength) override;
+                        uint32_t aMessageSize) override;
   void OnSessionKeysChange(const char* aSessionId,
                            uint32_t aSessionIdSize,
                            bool aHasAdditionalUsableKey,
@@ -58,12 +62,6 @@ public:
                           cdm::Time aNewExpiryTime) override;
   void OnSessionClosed(const char* aSessionId,
                        uint32_t aSessionIdSize) override;
-  void OnLegacySessionError(const char* aSessionId,
-                            uint32_t aSessionIdLength,
-                            cdm::Error aError,
-                            uint32_t aSystemCode,
-                            const char* aErrorMessage,
-                            uint32_t aErrorMessageLength) override;
   void SendPlatformChallenge(const char* aServiceId,
                              uint32_t aServiceIdSize,
                              const char* aChallenge,
@@ -72,8 +70,31 @@ public:
   void QueryOutputProtectionStatus() override {}
   void OnDeferredInitializationDone(cdm::StreamType aStreamType,
                                     cdm::Status aDecoderStatus) override {}
+  // cdm::Host_9 interface
+  // TODO: sync with unpstream, the interface has changed.
+  void RequestStorageId() override {}
   cdm::FileIO* CreateFileIO(cdm::FileIOClient* aClient) override;
 
+  // cdm::Host_8 implementation
+  void OnSessionMessage(const char* aSessionId,
+                        uint32_t aSessionIdSize,
+                        cdm::MessageType aMessageType,
+                        const char* aMessage,
+                        uint32_t aMessageSize,
+                        const char* aLegacyDestinationUrl,
+                        uint32_t aLegacyDestinationUrlLength) override;
+  void OnRejectPromise(uint32_t aPromiseId,
+                       cdm::Error aError,
+                       uint32_t aSystemCode,
+                       const char* aErrorMessage,
+                       uint32_t aErrorMessageSize) override;
+  void OnLegacySessionError(const char* aSessionId,
+                            uint32_t aSessionIdLength,
+                            cdm::Error aError,
+                            uint32_t aSystemCode,
+                            const char* aErrorMessage,
+                            uint32_t aErrorMessageLength) override;
+
   void GiveBuffer(ipc::Shmem&& aBuffer);
 
 protected:
@@ -128,7 +149,7 @@ protected:
   void CallOnMessageLoopThread(const char* const, MethodType, ParamType&&...);
 
   GMPContentChild* mPlugin = nullptr;
-  cdm::ContentDecryptionModule_8* mCDM = nullptr;
+  cdm::ContentDecryptionModule_9* mCDM = nullptr;
 
   typedef SimpleMap<uint64_t> DurationMap;
   DurationMap mFrameDurations;
diff --git a/dom/media/gmp/ChromiumCDMParent.cpp b/dom/media/gmp/ChromiumCDMParent.cpp
index 87c2b6da9c90..81c42701e3a3 100644
--- a/dom/media/gmp/ChromiumCDMParent.cpp
+++ b/dom/media/gmp/ChromiumCDMParent.cpp
@@ -359,29 +359,19 @@ ChromiumCDMParent::RejectPromise(uint32_t aPromiseId,
 }
 
 static nsresult
-ToNsresult(uint32_t aError)
+ToNsresult(uint32_t aException)
 {
-  switch (static_cast<cdm::Error>(aError)) {
-    case cdm::kNotSupportedError:
+  switch (static_cast<cdm::Exception>(aException)) {
+    case cdm::Exception::kExceptionNotSupportedError:
       return NS_ERROR_DOM_NOT_SUPPORTED_ERR;
-    case cdm::kInvalidStateError:
+    case cdm::Exception::kExceptionInvalidStateError:
       return NS_ERROR_DOM_INVALID_STATE_ERR;
-    case cdm::kInvalidAccessError:
-      // Note: Chrome converts kInvalidAccessError to TypeError, since the
-      // Chromium CDM API doesn't have a type error enum value. The EME spec
-      // requires TypeError in some places, so we do the same conversion.
-      // See bug 1313202.
+    case cdm::Exception::kExceptionTypeError:
       return NS_ERROR_DOM_TYPE_ERR;
-    case cdm::kQuotaExceededError:
+    case cdm::Exception::kExceptionQuotaExceededError:
       return NS_ERROR_DOM_QUOTA_EXCEEDED_ERR;
-    case cdm::kUnknownError:
-      return NS_ERROR_DOM_UNKNOWN_ERR; // Note: Unique placeholder.
-    case cdm::kClientError:
-      return NS_ERROR_DOM_ABORT_ERR; // Note: Unique placeholder.
-    case cdm::kOutputError:
-      return NS_ERROR_DOM_SECURITY_ERR; // Note: Unique placeholder.
   };
-  MOZ_ASSERT_UNREACHABLE("Invalid cdm::Error enum value.");
+  MOZ_ASSERT_UNREACHABLE("Invalid cdm::Exception enum value.");
   return NS_ERROR_DOM_TIMEOUT_ERR; // Note: Unique placeholder.
 }
 
diff --git a/dom/media/gmp/GMPContentChild.cpp b/dom/media/gmp/GMPContentChild.cpp
index ab761a5b2f6a..f47d235eecf0 100644
--- a/dom/media/gmp/GMPContentChild.cpp
+++ b/dom/media/gmp/GMPContentChild.cpp
@@ -129,20 +129,182 @@ GMPContentChild::RecvPGMPVideoEncoderConstructor(PGMPVideoEncoderChild* aActor)
   return IPC_OK();
 }
 
+
+class ChromiumCDM8BackwardsCompat : public cdm::ContentDecryptionModule_9
+{
+public:
+  explicit ChromiumCDM8BackwardsCompat(
+    cdm::Host_9* aHost,
+    cdm::ContentDecryptionModule_8* aCDM)
+      : mCDM(aCDM),
+        mHost(aHost) { }
+
+  void Initialize(bool aAllowDistinctiveIdentifier,
+                  bool aAllowPersistentState) override
+  {
+    mCDM->Initialize(aAllowDistinctiveIdentifier, aAllowPersistentState);
+  }
+
+  void SetServerCertificate(uint32_t aPromiseId,
+                            const uint8_t* aServerCertificateData,
+                            uint32_t aServerCertificateDataSize) override
+  {
+    mCDM->SetServerCertificate(aPromiseId,
+                               aServerCertificateData,
+                               aServerCertificateDataSize);
+  }
+
+  void GetStatusForPolicy(uint32_t aPromiseId,
+                          const cdm::Policy& policy) override
+  {
+    //Only support on version 9 CDM, so rejecting the promise.
+    mHost->OnRejectPromise(aPromiseId,
+                           cdm::Exception::kExceptionNotSupportedError,
+                           0,
+                           nullptr,
+                           0);
+
+  }
+
+  void CreateSessionAndGenerateRequest(uint32_t aPromiseId,
+                                       cdm::SessionType aSessionType,
+                                       cdm::InitDataType aInitDataType,
+                                       const uint8_t* aInitData,
+                                       uint32_t aInitDataSize) override
+  {
+    mCDM->CreateSessionAndGenerateRequest(
+      aPromiseId, aSessionType, aInitDataType, aInitData, aInitDataSize);
+  }
+
+  void LoadSession(uint32_t aPromiseId,
+                   cdm::SessionType aSessionType,
+                   const char* aSessionId,
+                   uint32_t aSessionIdSize) override
+  {
+    mCDM->LoadSession(aPromiseId, aSessionType, aSessionId, aSessionIdSize);
+  }
+
+  void UpdateSession(uint32_t aPromiseId,
+                     const char* aSessionId,
+                     uint32_t aSessionIdSize,
+                     const uint8_t* aResponse,
+                     uint32_t aResponseSize) override
+  {
+    mCDM->UpdateSession(aPromiseId,
+                        aSessionId,
+                        aSessionIdSize,
+                        aResponse,
+                        aResponseSize);
+  }
+
+  void CloseSession(uint32_t aPromiseId,
+                    const char* aSessionId,
+                    uint32_t aSessionIdSize) override
+  {
+    mCDM->CloseSession(aPromiseId, aSessionId, aSessionIdSize);
+  }
+
+  void RemoveSession(uint32_t aPromiseId,
+                     const char* aSessionId,
+                     uint32_t aSessionIdSize) override
+  {
+    mCDM->RemoveSession(aPromiseId, aSessionId, aSessionIdSize);
+  }
+
+  void TimerExpired(void* aContext) override { mCDM->TimerExpired(aContext); }
+
+  cdm::Status Decrypt(const cdm::InputBuffer& aEncryptedBuffer,
+                      cdm::DecryptedBlock* aDecryptedBuffer) override
+  {
+    return mCDM->Decrypt(aEncryptedBuffer, aDecryptedBuffer);
+  }
+
+  cdm::Status InitializeAudioDecoder(
+    const cdm::AudioDecoderConfig& aAudioDecoderConfig) override
+  {
+    return mCDM->InitializeAudioDecoder(aAudioDecoderConfig);
+  }
+
+  cdm::Status InitializeVideoDecoder(
+    const cdm::VideoDecoderConfig& aVideoDecoderConfig) override
+  {
+    return mCDM->InitializeVideoDecoder(aVideoDecoderConfig);
+  }
+
+  void DeinitializeDecoder(cdm::StreamType aDecoderType) override
+  {
+    mCDM->DeinitializeDecoder(aDecoderType);
+  }
+
+  void ResetDecoder(cdm::StreamType aDecoderType) override
+  {
+    mCDM->ResetDecoder(aDecoderType);
+  }
+
+  cdm::Status DecryptAndDecodeFrame(const cdm::InputBuffer& aEncryptedBuffer,
+                                    cdm::VideoFrame* aVideoFrame) override
+  {
+    return mCDM->DecryptAndDecodeFrame(aEncryptedBuffer, aVideoFrame);
+  }
+
+  cdm::Status DecryptAndDecodeSamples(const cdm::InputBuffer& aEncryptedBuffer,
+                                      cdm::AudioFrames* aAudioFrames) override
+  {
+    return mCDM->DecryptAndDecodeSamples(aEncryptedBuffer, aAudioFrames);
+  }
+
+  void OnPlatformChallengeResponse(
+      const cdm::PlatformChallengeResponse& aResponse) override
+  {
+    mCDM->OnPlatformChallengeResponse(aResponse);
+  }
+
+  void OnQueryOutputProtectionStatus(cdm::QueryResult aResult,
+                                     uint32_t aLinkMask,
+                                     uint32_t aOutputProtectionMask) override
+  {
+    mCDM->OnQueryOutputProtectionStatus(aResult, aLinkMask, aOutputProtectionMask);
+  }
+
+  void OnStorageId(const uint8_t* aStorageId,
+                   uint32_t aStorageIdSize) override
+  {
+    //Only support on version 9 CDM.
+  }
+
+  void Destroy() override
+  {
+    mCDM->Destroy();
+    delete this;
+  }
+  cdm::ContentDecryptionModule_8* mCDM;
+  cdm::Host_9* mHost;
+}; // class ChromiumCDM8BackwardsCompat
+
 mozilla::ipc::IPCResult
 GMPContentChild::RecvPChromiumCDMConstructor(PChromiumCDMChild* aActor)
 {
   ChromiumCDMChild* child = static_cast<ChromiumCDMChild*>(aActor);
-  cdm::Host_8* host = child;
+  cdm::Host_9* host9 = child;
 
   void* cdm = nullptr;
-  GMPErr err = mGMPChild->GetAPI(CHROMIUM_CDM_API, host, &cdm);
+  // Create version 9 CDM first.
+  GMPErr err = mGMPChild->GetAPI(CHROMIUM_CDM_API, host9, &cdm);
   if (err != GMPNoErr || !cdm) {
-    NS_WARNING("GMPGetAPI call failed trying to get CDM.");
-    return IPC_FAIL_NO_REASON(this);
+    // Try to create older version 8 CDM.
+    cdm::Host_8* host8 = child;
+    err = mGMPChild->GetAPI(CHROMIUM_CDM_API_BACKWARD_COMPAT, host8, &cdm);
+    cdm =
+      new ChromiumCDM8BackwardsCompat(
+        host9,
+        static_cast<cdm::ContentDecryptionModule_8*>(cdm));
+    if (err != GMPNoErr) {
+      NS_WARNING("GMPGetAPI call failed trying to get CDM.");
+      return IPC_FAIL_NO_REASON(this);
+    }
   }
 
-  child->Init(static_cast<cdm::ContentDecryptionModule_8*>(cdm));
+  child->Init(static_cast<cdm::ContentDecryptionModule_9*>(cdm));
 
   return IPC_OK();
 }
diff --git a/dom/media/gmp/GMPUtils.h b/dom/media/gmp/GMPUtils.h
index 21cadc7a1133..628b68561797 100644
--- a/dom/media/gmp/GMPUtils.h
+++ b/dom/media/gmp/GMPUtils.h
@@ -14,7 +14,8 @@
 #include "nsCOMPtr.h"
 #include "nsClassHashtable.h"
 
-#define CHROMIUM_CDM_API "chromium-cdm8-host4"
+#define CHROMIUM_CDM_API_BACKWARD_COMPAT "chromium-cdm8-host4"
+#define CHROMIUM_CDM_API "chromium-cdm9-host4"
 
 class nsIFile;
 class nsISimpleEnumerator;
diff --git a/dom/media/mediasink/AudioSink.cpp b/dom/media/mediasink/AudioSink.cpp
index 12e657a8df81..8986fc82e30c 100644
--- a/dom/media/mediasink/AudioSink.cpp
+++ b/dom/media/mediasink/AudioSink.cpp
@@ -424,28 +424,21 @@ AudioSink::NotifyAudioNeeded()
       missingFrames = std::min<int64_t>(INT32_MAX, missingFrames.value());
       mFramesParsed += missingFrames.value();
 
-      // We need to calculate how many frames are missing at the output rate.
-      missingFrames =
-        SaferMultDiv(missingFrames.value(), mOutputRate, data->mRate);
-      if (!missingFrames.isValid()) {
-        NS_WARNING("Int overflow in AudioSink");
-        mErrored = true;
-        return;
-      }
-
-      // We need to insert silence, first use drained frames if any.
-      missingFrames -= DrainConverter(missingFrames.value());
-      // Insert silence if still needed.
-      if (missingFrames.value()) {
-        AlignedAudioBuffer silenceData(missingFrames.value() * mOutputChannels);
-        if (!silenceData) {
-          NS_WARNING("OOM in AudioSink");
-          mErrored = true;
-          return;
-        }
-        RefPtr<AudioData> silence = CreateAudioFromBuffer(Move(silenceData), data);
-        PushProcessedAudio(silence);
+      RefPtr<AudioData> silenceData;
+      AlignedAudioBuffer silenceBuffer(missingFrames.value() * data->mChannels);
+       if (!silenceBuffer) {
+         NS_WARNING("OOM in AudioSink");
+         mErrored = true;
+         return;
+       }
+      if (mConverter->InputConfig() != mConverter->OutputConfig()) {
+        AlignedAudioBuffer convertedData =
+          mConverter->Process(AudioSampleBuffer(Move(silenceBuffer))).Forget();
+        silenceData = CreateAudioFromBuffer(Move(convertedData), data);
+      } else {
+        silenceData = CreateAudioFromBuffer(Move(silenceBuffer), data);
       }
+      PushProcessedAudio(silenceData);
     }
 
     mLastEndTime = data->GetEndTime();
@@ -486,7 +479,7 @@ AudioSink::PushProcessedAudio(AudioData* aData)
 
 already_AddRefed<AudioData>
 AudioSink::CreateAudioFromBuffer(AlignedAudioBuffer&& aBuffer,
-                                            AudioData* aReference)
+                                 AudioData* aReference)
 {
   uint32_t frames = aBuffer.Length() / mOutputChannels;
   if (!frames) {
diff --git a/dom/media/moz.build b/dom/media/moz.build
index ad95160beab1..00f480a39a70 100644
--- a/dom/media/moz.build
+++ b/dom/media/moz.build
@@ -215,7 +215,6 @@ UNIFIED_SOURCES += [
     'ChannelMediaDecoder.cpp',
     'ChannelMediaResource.cpp',
     'CloneableWithRangeMediaResource.cpp',
-    'CubebUtils.cpp',
     'DOMMediaStream.cpp',
     'FileBlockCache.cpp',
     'FileMediaResource.cpp',
@@ -278,8 +277,11 @@ if CONFIG['OS_TARGET'] == 'WINNT':
       'ThreadPoolCOMListener.cpp',
   ]
 
+# CubebUtils.cpp needs to be built separately due to what appears to be some kind
+# of compiler bug on Android 4.2 x86 opt. See bug 1408459.
 # DecoderTraits.cpp needs to be built separately because of Mac OS X headers.
 SOURCES += [
+    'CubebUtils.cpp',
     'DecoderTraits.cpp',
 ]
 
diff --git a/dom/media/test/crashtests/crashtests.list b/dom/media/test/crashtests/crashtests.list
index aa7280c9f6f3..72b1ff00c5c3 100644
--- a/dom/media/test/crashtests/crashtests.list
+++ b/dom/media/test/crashtests/crashtests.list
@@ -10,7 +10,7 @@ load 493915-1.html
 load 495794-1.html
 load 576612-1.html
 load 752784-1.html
-skip-if(Android) skip-if(webrender) load 789075-1.html # bug 1366502 comment 42, bug 1374405
+skip-if(Android) load 789075-1.html # bug 1374405
 skip-if(Android&&AndroidVersion=='22') HTTP load 795892-1.html # bug 1358718
 load 844563.html
 load 846612.html
diff --git a/dom/svg/SVGFETurbulenceElement.cpp b/dom/svg/SVGFETurbulenceElement.cpp
index b1830ca31ff7..06b7e6268e78 100644
--- a/dom/svg/SVGFETurbulenceElement.cpp
+++ b/dom/svg/SVGFETurbulenceElement.cpp
@@ -147,10 +147,17 @@ SVGFETurbulenceElement::GetPrimitiveDescription(nsSVGFilterInstance* aInstance,
   // words, we consider one turbulence base period to be 1 / fX user space
   // units wide and 1 / fY user space units high. We do not scale the frequency
   // depending on the filter primitive region.
-  gfxRect firstPeriodInUserSpace(0, 0, 1 / fX, 1 / fY);
+  // We now convert the frequency from user space to filter space.
+  // If a frequency in user space units is zero, then it will also be zero in
+  // filter space. During the conversion we use a dummy period length of 1
+  // for those frequencies but then ignore the converted length and use 0
+  // for the converted frequency. This avoids division by zero.
+  gfxRect firstPeriodInUserSpace(0, 0,
+                                 fX == 0 ? 1 : (1 / fX),
+                                 fY == 0 ? 1 : (1 / fY));
   gfxRect firstPeriodInFilterSpace = aInstance->UserSpaceToFilterSpace(firstPeriodInUserSpace);
-  Size frequencyInFilterSpace(1 / firstPeriodInFilterSpace.width,
-                              1 / firstPeriodInFilterSpace.height);
+  Size frequencyInFilterSpace(fX == 0 ? 0 : (1 / firstPeriodInFilterSpace.width),
+                              fY == 0 ? 0 : (1 / firstPeriodInFilterSpace.height));
   gfxPoint offset = firstPeriodInFilterSpace.TopLeft();
 
   FilterPrimitiveDescription descr(PrimitiveType::Turbulence);
diff --git a/dom/vr/test/reftest/change_size.html b/dom/vr/test/reftest/change_size.html
index 2cab613753e4..f34a200f4c07 100644
--- a/dom/vr/test/reftest/change_size.html
+++ b/dom/vr/test/reftest/change_size.html
@@ -89,7 +89,6 @@ If this fails, something is seriously wrong. -->
         return;
       }
 
-      vrDisplay.requestAnimationFrame(onAnimationFrame);
       gl.clearColor(0.0, 1.0, 0.0, 1.0);
       gl.clear(gl.COLOR_BUFFER_BIT);
 
@@ -121,6 +120,7 @@ If this fails, something is seriously wrong. -->
           img.src = submitResult.base64Image;
         }
       }
+      vrDisplay.requestAnimationFrame(onAnimationFrame);
     }
 
     function runTest() {
diff --git a/dom/vr/test/reftest/draw_rect.html b/dom/vr/test/reftest/draw_rect.html
index b32e456f170a..cc77595fb688 100644
--- a/dom/vr/test/reftest/draw_rect.html
+++ b/dom/vr/test/reftest/draw_rect.html
@@ -62,7 +62,6 @@ If this fails, something is seriously wrong. -->
         return;
       }
 
-      vrDisplay.requestAnimationFrame(onAnimationFrame);
       gl.clearColor(0.0, 1.0, 0.0, 1.0);
       gl.clear(gl.COLOR_BUFFER_BIT);
 
@@ -89,6 +88,7 @@ If this fails, something is seriously wrong. -->
           img.src = submitResult.base64Image;
         }
       }
+      vrDisplay.requestAnimationFrame(onAnimationFrame);
     }
 
     function runTest() {
diff --git a/dom/vr/test/reftest/reftest.list b/dom/vr/test/reftest/reftest.list
index b8cdfe53a291..2aafcc18e0b7 100644
--- a/dom/vr/test/reftest/reftest.list
+++ b/dom/vr/test/reftest/reftest.list
@@ -1,6 +1,6 @@
 # WebVR Reftests
 # Please confirm there is no other VR display connected. Otherwise, VRPuppetDisplay can't be attached.
-default-preferences pref(dom.vr.puppet.enabled,true) pref(dom.vr.test.enabled,true) pref(dom.vr.require-gesture,false) pref(dom.vr.puppet.submitframe,1)
+default-preferences pref(dom.vr.puppet.enabled,true) pref(dom.vr.test.enabled,true) pref(dom.vr.require-gesture,false) pref(dom.vr.puppet.submitframe,1) pref(dom.vr.display.rafMaxDuration,200)
 
 # VR SubmitFrame is only implemented for D3D11.1 and MacOSX now.
 # Our Windows 7 test machines don't support D3D11.1, so we run these tests on Windows 8+ only.
diff --git a/dom/webauthn/WebAuthnManager.cpp b/dom/webauthn/WebAuthnManager.cpp
index 85c40cab5357..04a7bc817804 100644
--- a/dom/webauthn/WebAuthnManager.cpp
+++ b/dom/webauthn/WebAuthnManager.cpp
@@ -697,6 +697,27 @@ WebAuthnManager::GetAssertion(nsPIDOMWindowInner* aParent,
   return promise.forget();
 }
 
+already_AddRefed<Promise>
+WebAuthnManager::Store(nsPIDOMWindowInner* aParent,
+                       const Credential& aCredential)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aParent);
+
+  MaybeClearTransaction();
+
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aParent);
+
+  ErrorResult rv;
+  RefPtr<Promise> promise = Promise::Create(global, rv);
+  if (rv.Failed()) {
+    return nullptr;
+  }
+
+  promise->MaybeReject(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
+  return promise.forget();
+}
+
 void
 WebAuthnManager::FinishMakeCredential(nsTArray<uint8_t>& aRegBuffer)
 {
diff --git a/dom/webauthn/WebAuthnManager.h b/dom/webauthn/WebAuthnManager.h
index 2578675adece..f2a14e7c8cbd 100644
--- a/dom/webauthn/WebAuthnManager.h
+++ b/dom/webauthn/WebAuthnManager.h
@@ -89,6 +89,9 @@ public:
   GetAssertion(nsPIDOMWindowInner* aParent,
                const PublicKeyCredentialRequestOptions& aOptions);
 
+  already_AddRefed<Promise>
+  Store(nsPIDOMWindowInner* aParent, const Credential& aCredential);
+
   void StartRegister();
   void StartSign();
   void StartCancel();
diff --git a/dom/webauthn/tests/mochitest.ini b/dom/webauthn/tests/mochitest.ini
index f636eb646f85..212a657bba89 100644
--- a/dom/webauthn/tests/mochitest.ini
+++ b/dom/webauthn/tests/mochitest.ini
@@ -10,5 +10,6 @@ scheme = https
 [test_webauthn_no_token.html]
 [test_webauthn_make_credential.html]
 [test_webauthn_get_assertion.html]
+[test_webauthn_store_credential.html]
 [test_webauthn_sameorigin.html]
 [test_webauthn_isplatformauthenticatoravailable.html]
diff --git a/dom/webauthn/tests/test_webauthn_store_credential.html b/dom/webauthn/tests/test_webauthn_store_credential.html
new file mode 100644
index 000000000000..b8692f42a78e
--- /dev/null
+++ b/dom/webauthn/tests/test_webauthn_store_credential.html
@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<head>
+  <title>Tests for Store for W3C Web Authentication</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+
+  <h1>Tests for Store for W3C Web Authentication</h1>
+  <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1309284">Mozilla Bug 1309284</a>
+
+  <script class="testbody" type="text/javascript">
+    "use strict";
+
+    function arrivingHereIsBad(aResult) {
+      ok(false, "Bad result! Received a: " + aResult);
+      return Promise.resolve();
+    }
+
+    function expectNotSupportedError(aResult) {
+      ok(aResult.toString().startsWith("NotSupportedError"), "Expecting a NotSupportedError, received: " + aResult);
+      return Promise.resolve();
+    }
+
+    add_task(async function(){
+      await SpecialPowers.pushPrefEnv({"set": [["security.webauth.webauthn", true],
+                                   ["security.webauth.webauthn_enable_softtoken", true],
+                                   ["security.webauth.webauthn_enable_usbtoken", false]]});
+
+      isnot(navigator.credentials, undefined, "Credential Management API endpoint must exist");
+      isnot(navigator.credentials.create, undefined, "CredentialManagement create API endpoint must exist");
+      isnot(navigator.credentials.get, undefined, "CredentialManagement get API endpoint must exist");
+      isnot(navigator.credentials.store, undefined, "CredentialManagement store API endpoint must exist");
+
+      let credentialChallenge = new Uint8Array(16);
+      window.crypto.getRandomValues(credentialChallenge);
+
+      let rp = {id: document.domain, name: "none", icon: "none"};
+      let user = {id: new Uint8Array(64), name: "none", icon: "none", displayName: "none"};
+      let params = [ {type: "public-key", alg: "es256"}, {type: "public-key", alg: -7} ]
+
+      let makeCredentialOptions = {
+        rp: rp, user: user, challenge: credentialChallenge, pubKeyCredParams: params
+      };
+
+      let credential = await navigator.credentials.create({publicKey: makeCredentialOptions})
+        .catch(arrivingHereIsBad);
+
+      await navigator.credentials.store(credential)
+        .then(arrivingHereIsBad)
+        .catch(expectNotSupportedError);
+    });
+  </script>
+
+</body>
+</html>
diff --git a/dom/webidl/CredentialManagement.webidl b/dom/webidl/CredentialManagement.webidl
index 533284184070..18ba4d3e15bd 100644
--- a/dom/webidl/CredentialManagement.webidl
+++ b/dom/webidl/CredentialManagement.webidl
@@ -17,6 +17,7 @@ interface Credential {
 interface CredentialsContainer {
   Promise<Credential?> get(optional CredentialRequestOptions options);
   Promise<Credential?> create(optional CredentialCreationOptions options);
+  Promise<Credential> store(Credential credential);
 };
 
 dictionary CredentialRequestOptions {
diff --git a/dom/xul/crashtests/crashtests.list b/dom/xul/crashtests/crashtests.list
index b71f617e1b99..62e2dde9d4b3 100644
--- a/dom/xul/crashtests/crashtests.list
+++ b/dom/xul/crashtests/crashtests.list
@@ -13,7 +13,7 @@ load 336096-1.xhtml
 load 344215-1.xul
 load 354611-1.html
 load 360078-1.xhtml
-load 363791-1.xul
+asserts-if(stylo,11-16) load 363791-1.xul # bug 1397644
 load 384740-1.xul
 load 384877-1.html
 load 386914-1.html
diff --git a/editor/libeditor/HTMLEditorObjectResizer.cpp b/editor/libeditor/HTMLEditorObjectResizer.cpp
index afd93789c1ba..0e17a75b4223 100644
--- a/editor/libeditor/HTMLEditorObjectResizer.cpp
+++ b/editor/libeditor/HTMLEditorObjectResizer.cpp
@@ -820,9 +820,6 @@ HTMLEditor::MouseMove(nsIDOMMouseEvent* aMouseEvent)
 {
   MOZ_ASSERT(aMouseEvent);
 
-  NS_NAMED_LITERAL_STRING(leftStr, "left");
-  NS_NAMED_LITERAL_STRING(topStr, "top");
-
   if (mIsResizing) {
     // we are resizing and the mouse pointer's position has changed
     // we have to resdisplay the shadow
diff --git a/editor/reftests/reftest.list b/editor/reftests/reftest.list
index 7461728ccef1..76428e030b88 100644
--- a/editor/reftests/reftest.list
+++ b/editor/reftests/reftest.list
@@ -1,5 +1,7 @@
 # include the XUL reftests
-include xul/reftest.list
+# All tests in this dir are affected by bug 1408811 on Stylo.
+# Some of them are != which pass on stylo but fails on styloVsGecko.
+skip-if(stylo) fails-if(styloVsGecko) include xul/reftest.list
 
 != newline-1.html newline-ref.html
 == newline-2.html newline-ref.html
diff --git a/gfx/2d/DrawEventRecorder.cpp b/gfx/2d/DrawEventRecorder.cpp
index c604682c5336..44123c4697fb 100644
--- a/gfx/2d/DrawEventRecorder.cpp
+++ b/gfx/2d/DrawEventRecorder.cpp
@@ -16,15 +16,6 @@ DrawEventRecorderPrivate::DrawEventRecorderPrivate()
 {
 }
 
-template<class S>
-void
-DrawEventRecorderPrivate::WriteHeader(S &aStream)
-{
-  WriteElement(aStream, kMagicInt);
-  WriteElement(aStream, kMajorRevision);
-  WriteElement(aStream, kMinorRevision);
-}
-
 void
 DrawEventRecorderFile::RecordEvent(const RecordedEvent &aEvent)
 {
diff --git a/gfx/2d/DrawEventRecorder.h b/gfx/2d/DrawEventRecorder.h
index b9552d4e0cc2..e753c8d70fac 100644
--- a/gfx/2d/DrawEventRecorder.h
+++ b/gfx/2d/DrawEventRecorder.h
@@ -8,6 +8,7 @@
 
 #include "2D.h"
 #include "RecordedEvent.h"
+#include "RecordingTypes.h"
 #include <ostream>
 #include <fstream>
 
@@ -39,7 +40,11 @@ public:
   }
 
   template<class S>
-  void WriteHeader(S &aStream);
+  void WriteHeader(S& aStream) {
+    WriteElement(aStream, kMagicInt);
+    WriteElement(aStream, kMajorRevision);
+    WriteElement(aStream, kMinorRevision);
+  }
 
   virtual void RecordEvent(const RecordedEvent &aEvent) = 0;
   void WritePath(const PathRecording *aPath);
diff --git a/gfx/2d/RecordedEvent.cpp b/gfx/2d/RecordedEvent.cpp
index 8a0e13f68c27..1da4aba7895e 100644
--- a/gfx/2d/RecordedEvent.cpp
+++ b/gfx/2d/RecordedEvent.cpp
@@ -23,6 +23,11 @@ RecordedEvent::LoadEventFromStream(std::istream &aStream, EventType aType) {
   return LoadEvent(aStream, aType);
 }
 
+RecordedEvent *
+RecordedEvent::LoadEventFromStream(EventStream& aStream, EventType aType) {
+  return LoadEvent(aStream, aType);
+}
+
 string
 RecordedEvent::GetEventName(EventType aType)
 {
diff --git a/gfx/2d/RecordedEvent.h b/gfx/2d/RecordedEvent.h
index 4646f0eeda09..6a25a228b836 100644
--- a/gfx/2d/RecordedEvent.h
+++ b/gfx/2d/RecordedEvent.h
@@ -207,6 +207,12 @@ struct MemStream {
   ~MemStream() { free(mData); }
 };
 
+class EventStream {
+public:
+  virtual void write(const char* aData, size_t aSize) = 0;
+  virtual void read(char* aOut, size_t aSize) = 0;
+};
+
 class RecordedEvent {
 public:
   enum EventType {
@@ -266,8 +272,9 @@ public:
    */
   virtual bool PlayEvent(Translator *aTranslator) const { return true; }
 
-  virtual void RecordToStream(std::ostream &aStream) const {}
-  virtual void RecordToStream(MemStream &aStream) const  = 0;
+  virtual void RecordToStream(std::ostream& aStream) const = 0;
+  virtual void RecordToStream(EventStream& aStream) const = 0;
+  virtual void RecordToStream(MemStream& aStream) const = 0;
 
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const { }
 
@@ -292,13 +299,14 @@ public:
   template<class S>
   static RecordedEvent *LoadEvent(S &aStream, EventType aType);
   static RecordedEvent *LoadEventFromStream(std::istream &aStream, EventType aType);
+  static RecordedEvent *LoadEventFromStream(EventStream& aStream, EventType aType);
 
   // An alternative to LoadEvent that avoids a heap allocation for the event.
   // This accepts a callable `f' that will take a RecordedEvent* as a single parameter
   template<class S, class F>
   static bool DoWithEvent(S &aStream, EventType aType, F f);
 
-  EventType GetType() { return (EventType)mType; }
+  EventType GetType() const { return (EventType)mType; }
 protected:
   friend class DrawEventRecorderPrivate;
   friend class DrawEventRecorderFile;
@@ -315,4 +323,3 @@ protected:
 } // namespace mozilla
 
 #endif
-
diff --git a/gfx/2d/RecordedEventImpl.h b/gfx/2d/RecordedEventImpl.h
index c3b15e10c940..114b865c6eeb 100644
--- a/gfx/2d/RecordedEventImpl.h
+++ b/gfx/2d/RecordedEventImpl.h
@@ -25,6 +25,9 @@ class RecordedEventDerived : public RecordedEvent {
   void RecordToStream(std::ostream &aStream) const {
     static_cast<const Derived*>(this)->Record(aStream);
   }
+  void RecordToStream(EventStream& aStream) const {
+    static_cast<const Derived*>(this)->Record(aStream);
+  }
   void RecordToStream(MemStream &aStream) const {
     SizeCollector size;
     static_cast<const Derived*>(this)->Record(size);
@@ -79,7 +82,7 @@ public:
   SurfaceFormat mFormat;
   bool mHasExistingData;
   RefPtr<SourceSurface> mExistingData;
-  
+
 private:
   friend class RecordedEvent;
 
@@ -511,7 +514,7 @@ public:
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "SetTransform"; }
 
   Matrix mTransform;
@@ -536,7 +539,7 @@ public:
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "DrawSurface"; }
 private:
   friend class RecordedEvent;
@@ -565,7 +568,7 @@ public:
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "DrawSurfaceWithShadow"; }
 private:
   friend class RecordedEvent;
@@ -614,12 +617,12 @@ class RecordedPathCreation : public RecordedEventDerived<RecordedPathCreation> {
 public:
   MOZ_IMPLICIT RecordedPathCreation(PathRecording *aPath);
   ~RecordedPathCreation();
-  
+
   virtual bool PlayEvent(Translator *aTranslator) const;
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "Path Creation"; }
   virtual ReferencePtr GetObjectRef() const { return mRefPtr; }
 private:
@@ -639,12 +642,12 @@ public:
     : RecordedEventDerived(PATHDESTRUCTION), mRefPtr(aPath)
   {
   }
-  
+
   virtual bool PlayEvent(Translator *aTranslator) const;
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "Path Destruction"; }
   virtual ReferencePtr GetObjectRef() const { return mRefPtr; }
 private:
@@ -671,7 +674,7 @@ public:
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "SourceSurface Creation"; }
   virtual ReferencePtr GetObjectRef() const { return mRefPtr; }
 private:
@@ -699,7 +702,7 @@ public:
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "SourceSurface Destruction"; }
   virtual ReferencePtr GetObjectRef() const { return mRefPtr; }
 private:
@@ -775,7 +778,7 @@ public:
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "GradientStops Creation"; }
   virtual ReferencePtr GetObjectRef() const { return mRefPtr; }
 private:
@@ -802,7 +805,7 @@ public:
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "GradientStops Destruction"; }
   virtual ReferencePtr GetObjectRef() const { return mRefPtr; }
 private:
@@ -825,7 +828,7 @@ public:
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "Snapshot"; }
   virtual ReferencePtr GetObjectRef() const { return mRefPtr; }
 private:
@@ -1045,7 +1048,7 @@ public:
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "ScaledFont Creation"; }
   virtual ReferencePtr GetObjectRef() const { return mRefPtr; }
 
@@ -1103,7 +1106,7 @@ public:
 
   template<class S> void Record(S &aStream) const;
   virtual void OutputSimpleEventInfo(std::stringstream &aStringStream) const;
-  
+
   virtual std::string GetName() const { return "MaskSurface"; }
 private:
   friend class RecordedEvent;
@@ -1288,7 +1291,7 @@ inline void
 RecordedEvent::StorePattern(PatternStorage &aDestination, const Pattern &aSource) const
 {
   aDestination.mType = aSource.GetType();
-  
+
   switch (aSource.GetType()) {
   case PatternType::COLOR:
     {
@@ -2283,7 +2286,7 @@ RecordedPathCreation::~RecordedPathCreation()
 inline bool
 RecordedPathCreation::PlayEvent(Translator *aTranslator) const
 {
-  RefPtr<PathBuilder> builder = 
+  RefPtr<PathBuilder> builder =
     aTranslator->GetReferenceDrawTarget()->CreatePathBuilder(mFillRule);
 
   for (size_t i = 0; i < mPathOps.size(); i++) {
diff --git a/gfx/ipc/GPUParent.cpp b/gfx/ipc/GPUParent.cpp
index 3ad96ae72880..1a60cd23adbe 100644
--- a/gfx/ipc/GPUParent.cpp
+++ b/gfx/ipc/GPUParent.cpp
@@ -37,6 +37,7 @@
 #include "ProcessUtils.h"
 #include "VRManager.h"
 #include "VRManagerParent.h"
+#include "VRThread.h"
 #include "VsyncBridgeParent.h"
 #if defined(XP_WIN)
 # include "mozilla/gfx/DeviceManagerDx.h"
@@ -120,6 +121,8 @@ GPUParent::Init(base::ProcessId aParentPid,
   }
 
   CompositorThreadHolder::Start();
+  // TODO: Bug 1406327, Start VRListenerThreadHolder when loading VR content.
+  VRListenerThreadHolder::Start();
   APZThreadUtils::SetControllerThread(CompositorThreadHolder::Loop());
   APZCTreeManager::InitializeGlobalState();
   LayerTreeOwnerTracker::Initialize();
@@ -431,6 +434,7 @@ GPUParent::ActorDestroy(ActorDestroyReason aWhy)
   }
   dom::VideoDecoderManagerParent::ShutdownVideoBridge();
   CompositorThreadHolder::Shutdown();
+  VRListenerThreadHolder::Shutdown();
   if (gfxVars::UseWebRender()) {
     wr::RenderThread::ShutDown();
   }
diff --git a/gfx/layers/apz/src/FocusState.cpp b/gfx/layers/apz/src/FocusState.cpp
index cb8f29fa5050..5c7c94548c81 100644
--- a/gfx/layers/apz/src/FocusState.cpp
+++ b/gfx/layers/apz/src/FocusState.cpp
@@ -43,10 +43,10 @@ FocusState::Update(uint64_t aRootLayerTreeId,
                    uint64_t aOriginatingLayersId,
                    const FocusTarget& aState)
 {
-  FS_LOG("Update with rlt=%" PRIu64 ", olt=%" PRIu64 ", ft=(%d, %" PRIu64 ")\n",
+  FS_LOG("Update with rlt=%" PRIu64 ", olt=%" PRIu64 ", ft=(%s, %" PRIu64 ")\n",
          aRootLayerTreeId,
          aOriginatingLayersId,
-         static_cast<int>(aState.mType),
+         aState.Type(),
          aState.mSequenceNumber);
 
   // Update the focus tree with the latest target
diff --git a/gfx/layers/apz/src/FocusTarget.cpp b/gfx/layers/apz/src/FocusTarget.cpp
index efa42f512db6..7613bff17137 100644
--- a/gfx/layers/apz/src/FocusTarget.cpp
+++ b/gfx/layers/apz/src/FocusTarget.cpp
@@ -230,5 +230,20 @@ FocusTarget::operator==(const FocusTarget& aRhs) const
          mData == aRhs.mData;
 }
 
+const char*
+FocusTarget::Type() const
+{
+  if (mData.is<RefLayerId>()) {
+    return "RefLayerId";
+  }
+  if (mData.is<ScrollTargets>()) {
+    return "ScrollTargets";
+  }
+  if (mData.is<NoFocusTarget>()) {
+    return "NoFocusTarget";
+  }
+  return "<unknown>";
+}
+
 } // namespace layers
 } // namespace mozilla
diff --git a/gfx/layers/apz/src/FocusTarget.h b/gfx/layers/apz/src/FocusTarget.h
index 96d4d5c94a2f..2741d6f5516d 100644
--- a/gfx/layers/apz/src/FocusTarget.h
+++ b/gfx/layers/apz/src/FocusTarget.h
@@ -59,6 +59,8 @@ public:
 
   bool operator==(const FocusTarget& aRhs) const;
 
+  const char* Type() const;
+
 public:
   // The content sequence number recorded at the time of this class's creation
   uint64_t mSequenceNumber;
diff --git a/gfx/layers/ipc/CompositorVsyncScheduler.cpp b/gfx/layers/ipc/CompositorVsyncScheduler.cpp
index 829087efd1ee..6ab1abd511f1 100644
--- a/gfx/layers/ipc/CompositorVsyncScheduler.cpp
+++ b/gfx/layers/ipc/CompositorVsyncScheduler.cpp
@@ -35,6 +35,7 @@
 #endif
 #include "mozilla/widget/CompositorWidget.h"
 #include "VRManager.h"
+#include "VRThread.h"
 
 namespace mozilla {
 
@@ -83,6 +84,8 @@ CompositorVsyncScheduler::CompositorVsyncScheduler(CompositorVsyncSchedulerOwner
   , mCurrentCompositeTask(nullptr)
   , mSetNeedsCompositeMonitor("SetNeedsCompositeMonitor")
   , mSetNeedsCompositeTask(nullptr)
+  , mCurrentVRListenerTaskMonitor("CurrentVRTaskMonitor")
+  , mCurrentVRListenerTask(nullptr)
 {
   mVsyncObserver = new Observer(this);
 
@@ -130,6 +133,16 @@ CompositorVsyncScheduler::PostCompositeTask(TimeStamp aCompositeTimestamp)
     mCurrentCompositeTask = task;
     ScheduleTask(task.forget(), 0);
   }
+  if (mCurrentVRListenerTask == nullptr && VRListenerThreadHolder::Loop()) {
+    RefPtr<CancelableRunnable> task = NewCancelableRunnableMethod<TimeStamp>(
+      "layers::CompositorVsyncScheduler::DispatchVREvents",
+      this,
+      &CompositorVsyncScheduler::DispatchVREvents,
+      aCompositeTimestamp);
+    mCurrentVRListenerTask = task;
+    MOZ_ASSERT(VRListenerThreadHolder::Loop());
+    VRListenerThreadHolder::Loop()->PostDelayedTask(Move(task.forget()), 0);
+  }
 }
 
 void
@@ -254,7 +267,6 @@ CompositorVsyncScheduler::Composite(TimeStamp aVsyncTimestamp)
   }
 
   DispatchTouchEvents(aVsyncTimestamp);
-  DispatchVREvents(aVsyncTimestamp);
 
   if (mNeedsComposite || mAsapScheduling) {
     mNeedsComposite = 0;
@@ -327,7 +339,11 @@ CompositorVsyncScheduler::DispatchTouchEvents(TimeStamp aVsyncTimestamp)
 void
 CompositorVsyncScheduler::DispatchVREvents(TimeStamp aVsyncTimestamp)
 {
-  MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread());
+  MOZ_ASSERT(VRListenerThreadHolder::IsInVRListenerThread());
+  {
+    MonitorAutoLock lock(mCurrentVRListenerTaskMonitor);
+    mCurrentVRListenerTask = nullptr;
+  }
 
   VRManager* vm = VRManager::Get();
   vm->NotifyVsync(aVsyncTimestamp);
diff --git a/gfx/layers/ipc/CompositorVsyncScheduler.h b/gfx/layers/ipc/CompositorVsyncScheduler.h
index 2354cce7db06..0d45a1ef3d40 100644
--- a/gfx/layers/ipc/CompositorVsyncScheduler.h
+++ b/gfx/layers/ipc/CompositorVsyncScheduler.h
@@ -117,6 +117,9 @@ private:
 
   mozilla::Monitor mSetNeedsCompositeMonitor;
   RefPtr<CancelableRunnable> mSetNeedsCompositeTask;
+
+  mozilla::Monitor mCurrentVRListenerTaskMonitor;
+  RefPtr<CancelableRunnable> mCurrentVRListenerTask;
 };
 
 } // namespace layers
diff --git a/gfx/tests/crashtests/crashtests.list b/gfx/tests/crashtests/crashtests.list
index 4bce1639d70e..c58b2c681db8 100644
--- a/gfx/tests/crashtests/crashtests.list
+++ b/gfx/tests/crashtests/crashtests.list
@@ -122,7 +122,7 @@ load 893572-3.html
 load 893572-4.html
 pref(layers.force-active,true) load 914457-1.html
 load 944579.svg
-skip-if(webrender&&debug) load 944579.html
+load 944579.html
 pref(security.fileuri.strict_origin_policy,false) load 950000.html
 load 1034403-1.html
 load 1056516.html
diff --git a/gfx/thebes/gfxPlatform.cpp b/gfx/thebes/gfxPlatform.cpp
index 8f450f2e3602..2496550dade1 100644
--- a/gfx/thebes/gfxPlatform.cpp
+++ b/gfx/thebes/gfxPlatform.cpp
@@ -28,6 +28,7 @@
 #include "gfxUserFontSet.h"
 #include "gfxConfig.h"
 #include "MediaPrefs.h"
+#include "VRThread.h"
 
 #ifdef XP_WIN
 #include <process.h>
@@ -1038,6 +1039,7 @@ gfxPlatform::InitLayersIPC()
     }
 
     layers::CompositorThreadHolder::Start();
+    gfx::VRListenerThreadHolder::Start();
   }
 }
 
@@ -1066,6 +1068,7 @@ gfxPlatform::ShutdownLayersIPC()
         layers::ImageBridgeChild::ShutDown();
         // This has to happen after shutting down the child protocols.
         layers::CompositorThreadHolder::Shutdown();
+        gfx::VRListenerThreadHolder::Shutdown();
         if (gfxVars::UseWebRender()) {
           wr::RenderThread::ShutDown();
 
diff --git a/gfx/thebes/gfxPrefs.h b/gfx/thebes/gfxPrefs.h
index 8f1b097f424e..e46dccd15ef7 100644
--- a/gfx/thebes/gfxPrefs.h
+++ b/gfx/thebes/gfxPrefs.h
@@ -369,6 +369,7 @@ private:
   DECL_GFX_PREF(Live, "dom.vr.require-gesture",                VRRequireGesture, bool, true);
   DECL_GFX_PREF(Live, "dom.vr.puppet.enabled",                 VRPuppetEnabled, bool, false);
   DECL_GFX_PREF(Live, "dom.vr.puppet.submitframe",             VRPuppetSubmitFrame, uint32_t, 0);
+  DECL_GFX_PREF(Live, "dom.vr.display.rafMaxDuration",         VRDisplayRafMaxDuration, uint32_t, 50);
   DECL_GFX_PREF(Live, "dom.w3c_pointer_events.enabled",        PointerEventsEnabled, bool, false);
   DECL_GFX_PREF(Live, "dom.w3c_touch_events.enabled",          TouchEventsEnabled, int32_t, 0);
 
diff --git a/gfx/vr/VRDisplayHost.cpp b/gfx/vr/VRDisplayHost.cpp
index 6086f1ecccf5..205a2375a0b9 100644
--- a/gfx/vr/VRDisplayHost.cpp
+++ b/gfx/vr/VRDisplayHost.cpp
@@ -4,10 +4,12 @@
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "VRDisplayHost.h"
+#include "gfxPrefs.h"
 #include "gfxVR.h"
 #include "ipc/VRLayerParent.h"
 #include "mozilla/layers/TextureHost.h"
 #include "mozilla/dom/GamepadBinding.h" // For GamepadMappingType
+#include "VRThread.h"
 
 #if defined(XP_WIN)
 
@@ -196,7 +198,7 @@ VRDisplayHost::NotifyVSync()
   /**
    * We will trigger a new frame immediately after a successful frame texture
    * submission.  If content fails to call VRDisplay.submitFrame after
-   * kVRDisplayRAFMaxDuration milliseconds has elapsed since the last
+   * dom.vr.display.rafMaxDuration milliseconds has elapsed since the last
    * VRDisplay.requestAnimationFrame, we act as a "watchdog" and kick-off
    * a new VRDisplay.requestAnimationFrame to avoid a render loop stall and
    * to give content a chance to recover.
@@ -208,13 +210,7 @@ VRDisplayHost::NotifyVSync()
    * potentially extreme frame rates.  To ensure that content has a chance to
    * resume its presentation when the frames are accepted once again, we rely
    * on this "watchdog" to act as a VR refresh driver cycling at a rate defined
-   * by kVRDisplayRAFMaxDuration.
-   *
-   * kVRDisplayRAFMaxDuration is the number of milliseconds since last frame
-   * start before triggering a new frame.  When content is failing to submit
-   * frames on time or the lower level VR platform API's are rejecting frames,
-   * kVRDisplayRAFMaxDuration determines the rate at which RAF callbacks
-   * will be called.
+   * by dom.vr.display.rafMaxDuration.
    *
    * This number must be larger than the slowest expected frame time during
    * normal VR presentation, but small enough not to break content that
@@ -222,12 +218,10 @@ VRDisplayHost::NotifyVSync()
    *
    * The slowest expected refresh rate for a VR display currently is an
    * Oculus CV1 when ASW (Asynchronous Space Warp) is enabled, at 45hz.
-   * A kVRDisplayRAFMaxDuration value of 50 milliseconds results in a 20hz
+   * A dom.vr.display.rafMaxDuration value of 50 milliseconds results in a 20hz
    * rate, which avoids inadvertent triggering of the watchdog during
    * Oculus ASW even if every second frame is dropped.
    */
-  const double kVRDisplayRAFMaxDuration = 50;
-
   bool bShouldStartFrame = false;
 
   if (mDisplayInfo.mPresentingGroups == 0) {
@@ -241,7 +235,7 @@ VRDisplayHost::NotifyVSync()
       bShouldStartFrame = true;
     } else {
       TimeDuration duration = TimeStamp::Now() - mLastFrameStart;
-      if (duration.ToMilliseconds() > kVRDisplayRAFMaxDuration) {
+      if (duration.ToMilliseconds() > gfxPrefs::VRDisplayRafMaxDuration()) {
         bShouldStartFrame = true;
       }
     }
@@ -273,7 +267,6 @@ VRDisplayHost::SubmitFrame(VRLayerParent* aLayer,
     return;
   }
   mFrameStarted = false;
-
   switch (aTexture.type()) {
 
 #if defined(XP_WIN)
@@ -345,7 +338,6 @@ VRDisplayHost::SubmitFrame(VRLayerParent* aLayer,
   }
 
 #if defined(XP_WIN) || defined(XP_MACOSX)
-
   /**
    * Trigger the next VSync immediately after we are successfully
    * submitting frames.  As SubmitFrame is responsible for throttling
@@ -356,9 +348,13 @@ VRDisplayHost::SubmitFrame(VRLayerParent* aLayer,
    * frames to continue at a lower refresh rate until frame submission
    * succeeds again.
    */
-  VRManager *vm = VRManager::Get();
-  MOZ_ASSERT(vm);
-  vm->NotifyVRVsync(mDisplayInfo.mDisplayID);
+  VRManager* vm = VRManager::Get();
+  MessageLoop* loop = VRListenerThreadHolder::Loop();
+
+  loop->PostTask(NewRunnableMethod<const uint32_t>(
+    "gfx::VRManager::NotifyVRVsync",
+    vm, &VRManager::NotifyVRVsync, mDisplayInfo.mDisplayID
+  ));
 #endif
 }
 
diff --git a/gfx/vr/VRManager.cpp b/gfx/vr/VRManager.cpp
index 1916dc212e78..dfa2d9dc3d9b 100644
--- a/gfx/vr/VRManager.cpp
+++ b/gfx/vr/VRManager.cpp
@@ -6,11 +6,13 @@
 
 #include "VRManager.h"
 #include "VRManagerParent.h"
+#include "VRThread.h"
 #include "gfxVR.h"
 #include "mozilla/ClearOnShutdown.h"
 #include "mozilla/dom/VRDisplay.h"
 #include "mozilla/dom/GamepadEventTypes.h"
 #include "mozilla/layers/TextureHost.h"
+#include "mozilla/layers/CompositorThread.h"
 #include "mozilla/Unused.h"
 
 #include "gfxPrefs.h"
@@ -161,6 +163,7 @@ VRManager::RemoveVRManagerParent(VRManagerParent* aVRManagerParent)
 void
 VRManager::NotifyVsync(const TimeStamp& aVsyncTimestamp)
 {
+  MOZ_ASSERT(VRListenerThreadHolder::IsInVRListenerThread());
   const double kVRDisplayRefreshMaxDuration = 5000; // milliseconds
   const double kVRDisplayInactiveMaxDuration = 30000; // milliseconds
 
@@ -236,6 +239,7 @@ VRManager::NotifyVsync(const TimeStamp& aVsyncTimestamp)
 void
 VRManager::NotifyVRVsync(const uint32_t& aDisplayID)
 {
+  MOZ_ASSERT(VRListenerThreadHolder::IsInVRListenerThread());
   for (const auto& manager: mManagers) {
     if (manager->GetIsPresenting()) {
       manager->HandleInput();
diff --git a/gfx/vr/VRThread.cpp b/gfx/vr/VRThread.cpp
new file mode 100644
index 000000000000..63dad4c85d17
--- /dev/null
+++ b/gfx/vr/VRThread.cpp
@@ -0,0 +1,123 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+#include "VRThread.h"
+#include "nsThreadUtils.h"
+
+namespace mozilla {
+
+namespace gfx {
+
+static StaticRefPtr<VRListenerThreadHolder> sVRListenerThreadHolder;
+static bool sFinishedVRListenerShutDown = false;
+
+VRListenerThreadHolder* GetVRListenerThreadHolder()
+{
+  return sVRListenerThreadHolder;
+}
+
+base::Thread*
+VRListenerThread()
+{
+  return sVRListenerThreadHolder
+         ? sVRListenerThreadHolder->GetThread()
+         : nullptr;
+}
+
+/* static */ MessageLoop*
+VRListenerThreadHolder::Loop()
+{
+  return VRListenerThread() ? VRListenerThread()->message_loop() : nullptr;
+}
+
+VRListenerThreadHolder*
+VRListenerThreadHolder::GetSingleton()
+{
+  return sVRListenerThreadHolder;
+}
+
+VRListenerThreadHolder::VRListenerThreadHolder()
+ : mThread(CreateThread())
+{
+  MOZ_ASSERT(NS_IsMainThread());
+}
+
+VRListenerThreadHolder::~VRListenerThreadHolder()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  DestroyThread(mThread);
+}
+
+/* static */ void
+VRListenerThreadHolder::DestroyThread(base::Thread* aThread)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!sVRListenerThreadHolder,
+             "We shouldn't be destroying the VR listener thread yet.");
+  delete aThread;
+  sFinishedVRListenerShutDown = true;
+}
+
+/* static */ base::Thread*
+VRListenerThreadHolder::CreateThread()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!sVRListenerThreadHolder, "The VR listener thread has already been started!");
+
+  base::Thread* vrThread = new base::Thread("VRListener");
+  base::Thread::Options options;
+  /* Timeout values are powers-of-two to enable us get better data.
+     128ms is chosen for transient hangs because 8Hz should be the minimally
+     acceptable goal for Compositor responsiveness (normal goal is 60Hz). */
+  options.transient_hang_timeout = 128; // milliseconds
+  /* 2048ms is chosen for permanent hangs because it's longer than most
+   * Compositor hangs seen in the wild, but is short enough to not miss getting
+   * native hang stacks. */
+  options.permanent_hang_timeout = 2048; // milliseconds
+
+  if (!vrThread->StartWithOptions(options)) {
+    delete vrThread;
+    return nullptr;
+  }
+
+  return vrThread;
+}
+
+void
+VRListenerThreadHolder::Start()
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Should be on the main thread!");
+  MOZ_ASSERT(!sVRListenerThreadHolder, "The VR listener thread has already been started!");
+
+  sVRListenerThreadHolder = new VRListenerThreadHolder();
+}
+
+void
+VRListenerThreadHolder::Shutdown()
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Should be on the main thread!");
+  MOZ_ASSERT(sVRListenerThreadHolder, "The VR listener thread has already been shut down!");
+
+  sVRListenerThreadHolder = nullptr;
+
+  SpinEventLoopUntil([&]() { return sFinishedVRListenerShutDown; });
+}
+
+/* static */ bool
+VRListenerThreadHolder::IsInVRListenerThread()
+{
+  return VRListenerThread() &&
+		 VRListenerThread()->thread_id() == PlatformThread::CurrentId();
+}
+
+} // namespace gfx
+} // namespace mozilla
+
+bool
+NS_IsInVRListenerThread()
+{
+  return mozilla::gfx::VRListenerThreadHolder::IsInVRListenerThread();
+}
\ No newline at end of file
diff --git a/gfx/vr/VRThread.h b/gfx/vr/VRThread.h
new file mode 100644
index 000000000000..9faff13f033c
--- /dev/null
+++ b/gfx/vr/VRThread.h
@@ -0,0 +1,51 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+ #ifndef GFX_VR_THREAD_H
+ #define GFX_VR_THREAD_H
+
+#include "ThreadSafeRefcountingWithMainThreadDestruction.h"
+#include "base/thread.h"                // for Thread
+
+namespace mozilla {
+namespace gfx {
+
+class VRListenerThreadHolder final
+{
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_MAIN_THREAD_DESTRUCTION(VRListenerThreadHolder)
+
+public:
+  VRListenerThreadHolder();
+
+  base::Thread* GetThread() const {
+    return mThread;
+  }
+
+  static VRListenerThreadHolder* GetSingleton();
+
+  static bool IsActive() {
+    return !!GetSingleton();
+  }
+
+  static void Start();
+  static void Shutdown();
+  static MessageLoop* Loop();
+  static bool IsInVRListenerThread();
+
+private:
+  ~VRListenerThreadHolder();
+
+  base::Thread* const mThread;
+
+  static base::Thread* CreateThread();
+  static void DestroyThread(base::Thread* aThread);
+};
+
+base::Thread* VRListenerThread();
+
+} // namespace gfx
+} // namespace mozilla
+
+#endif // GFX_VR_THREAD_H
\ No newline at end of file
diff --git a/gfx/vr/gfxVROculus.cpp b/gfx/vr/gfxVROculus.cpp
index 7a95103867ae..0e6e38af007f 100755
--- a/gfx/vr/gfxVROculus.cpp
+++ b/gfx/vr/gfxVROculus.cpp
@@ -18,6 +18,7 @@
 #include "mozilla/Preferences.h"
 #include "mozilla/TimeStamp.h"
 #include "mozilla/gfx/DeviceManagerDx.h"
+#include "mozilla/layers/CompositorThread.h"
 #include "ipc/VRLayerParent.h"
 
 #include "mozilla/gfx/Quaternion.h"
@@ -27,8 +28,8 @@
 #include "TextureD3D11.h"
 
 #include "gfxVROculus.h"
+#include "VRThread.h"
 
-#include "mozilla/layers/CompositorThread.h"
 #include "mozilla/dom/GamepadEventTypes.h"
 #include "mozilla/dom/GamepadBinding.h"
 #include "mozilla/Telemetry.h"
@@ -198,6 +199,7 @@ VROculusSession::VROculusSession()
   , mInitFlags((ovrInitFlags)0)
   , mTextureSet(nullptr)
   , mPresenting(false)
+  , mDrawBlack(false)
 {
 }
 
@@ -321,8 +323,14 @@ VROculusSession::StopLib()
 }
 
 void
-VROculusSession::Refresh()
+VROculusSession::Refresh(bool aForceRefresh)
 {
+  // We are waiting for drawing the black layer command for
+  // Compositor thread. Ignore Refresh() calls from other threads.
+  if (mDrawBlack && !aForceRefresh) {
+    return;
+  }
+
   ovrInitFlags flags = (ovrInitFlags)(ovrInit_RequestVersion | ovrInit_MixedRendering);
   bool bInvisible = true;
   if (mPresenting) {
@@ -340,11 +348,25 @@ VROculusSession::Refresh()
       // While we are waiting for either the timeout or a new presentation,
       // fill the HMD with black / no layers.
       if (mSession && mTextureSet) {
+        if (!aForceRefresh) {
+          // ovr_SubmitFrame is only allowed been run at Compositor thread,
+          // so we post this task to Compositor thread and let it determine
+          // if reloading library.
+          mDrawBlack = true;
+          MessageLoop* loop = layers::CompositorThreadHolder::Loop();
+          loop->PostTask(NewRunnableMethod<bool>(
+            "gfx::VROculusSession::Refresh",
+            this,
+            &VROculusSession::Refresh, true));
+
+          return;
+        }
         ovrLayerEyeFov layer;
         memset(&layer, 0, sizeof(layer));
         layer.Header.Type = ovrLayerType_Disabled;
         ovrLayerHeader *layers = &layer.Header;
         ovr_SubmitFrame(mSession, 0, nullptr, &layers, 1);
+        mDrawBlack = false;
       }
     }
   }
@@ -1385,9 +1407,9 @@ VRControllerOculus::VibrateHapticComplete(ovrSession aSession, uint32_t aPromise
   VRManager *vm = VRManager::Get();
   MOZ_ASSERT(vm);
 
-  CompositorThreadHolder::Loop()->PostTask(NewRunnableMethod<uint32_t>(
-                                             "VRManager::NotifyVibrateHapticCompleted",
-                                             vm, &VRManager::NotifyVibrateHapticCompleted, aPromiseID));
+  VRListenerThreadHolder::Loop()->PostTask(NewRunnableMethod<uint32_t>(
+                                           "VRManager::NotifyVibrateHapticCompleted",
+                                           vm, &VRManager::NotifyVibrateHapticCompleted, aPromiseID));
 }
 
 void
diff --git a/gfx/vr/gfxVROculus.h b/gfx/vr/gfxVROculus.h
index 77ca663c7d5e..39ccd55703ca 100644
--- a/gfx/vr/gfxVROculus.h
+++ b/gfx/vr/gfxVROculus.h
@@ -40,7 +40,7 @@ class VROculusSession
   friend class VRDisplayOculus;
 public:
   VROculusSession();
-  void Refresh();
+  void Refresh(bool aForceRefresh = false);
   bool IsTrackingReady() const;
   bool IsRenderReady() const;
   ovrSession Get();
@@ -65,6 +65,7 @@ private:
   TimeStamp mLastPresentationEnd;
   VRTelemetry mTelemetry;
   bool mPresenting;
+  bool mDrawBlack;
 
   ~VROculusSession();
   void Uninitialize(bool aUnloadLib);
diff --git a/gfx/vr/gfxVROpenVR.cpp b/gfx/vr/gfxVROpenVR.cpp
index 9ab7b2b960ce..dc03c0645e6c 100644
--- a/gfx/vr/gfxVROpenVR.cpp
+++ b/gfx/vr/gfxVROpenVR.cpp
@@ -21,11 +21,11 @@
 
 #include "gfxVROpenVR.h"
 #include "VRManager.h"
+#include "VRThread.h"
 
 #include "nsServiceManagerUtils.h"
 #include "nsIScreenManager.h"
 
-#include "mozilla/layers/CompositorThread.h"
 #include "mozilla/dom/GamepadEventTypes.h"
 #include "mozilla/dom/GamepadBinding.h"
 #include "mozilla/Telemetry.h"
@@ -531,9 +531,9 @@ VRControllerOpenVR::VibrateHapticComplete(uint32_t aPromiseID)
 {
   VRManager *vm = VRManager::Get();
 
-  CompositorThreadHolder::Loop()->PostTask(NewRunnableMethod<uint32_t>
-    ("VRManager::NotifyVibrateHapticCompleted",
-     vm, &VRManager::NotifyVibrateHapticCompleted, aPromiseID));
+  VRListenerThreadHolder::Loop()->PostTask(NewRunnableMethod<uint32_t>(
+                                           "VRManager::NotifyVibrateHapticCompleted",
+                                           vm, &VRManager::NotifyVibrateHapticCompleted, aPromiseID));
 }
 
 void
diff --git a/gfx/vr/gfxVRPuppet.cpp b/gfx/vr/gfxVRPuppet.cpp
index 09b0198d886e..a10e6eb59f02 100755
--- a/gfx/vr/gfxVRPuppet.cpp
+++ b/gfx/vr/gfxVRPuppet.cpp
@@ -17,6 +17,7 @@
 #include "gfxUtils.h"
 #include "gfxVRPuppet.h"
 #include "VRManager.h"
+#include "VRThread.h"
 
 #include "mozilla/dom/GamepadEventTypes.h"
 #include "mozilla/dom/GamepadBinding.h"
@@ -377,7 +378,11 @@ VRDisplayPuppet::SubmitFrame(ID3D11Texture2D* aSource,
       mContext->Unmap(mappedTexture, 0);
       // Dispatch the base64 encoded string to the DOM side. Then, it will be decoded
       // and convert to a PNG image there.
-      vm->DispatchSubmitFrameResult(mDisplayInfo.mDisplayID, result);
+      MessageLoop* loop = VRListenerThreadHolder::Loop();
+      loop->PostTask(NewRunnableMethod<const uint32_t, VRSubmitFrameResultInfo>(
+        "VRManager::DispatchSubmitFrameResult",
+        vm, &VRManager::DispatchSubmitFrameResult, mDisplayInfo.mDisplayID, result
+      ));
       break;
     }
     case 2:
@@ -518,7 +523,11 @@ VRDisplayPuppet::SubmitFrame(MacIOSurface* aMacIOSurface,
         }
         // Dispatch the base64 encoded string to the DOM side. Then, it will be decoded
         // and convert to a PNG image there.
-        vm->DispatchSubmitFrameResult(mDisplayInfo.mDisplayID, result);
+        MessageLoop* loop = VRListenerThreadHolder::Loop();
+        loop->PostTask(NewRunnableMethod<const uint32_t, VRSubmitFrameResultInfo>(
+          "VRManager::DispatchSubmitFrameResult",
+          vm, &VRManager::DispatchSubmitFrameResult, mDisplayInfo.mDisplayID, result
+        ));
       }
       break;
     }
diff --git a/gfx/vr/ipc/VRLayerParent.cpp b/gfx/vr/ipc/VRLayerParent.cpp
index 919781d064ec..615ac82042f7 100644
--- a/gfx/vr/ipc/VRLayerParent.cpp
+++ b/gfx/vr/ipc/VRLayerParent.cpp
@@ -7,8 +7,10 @@
 #include "VRLayerParent.h"
 #include "mozilla/Unused.h"
 #include "VRDisplayHost.h"
+#include "mozilla/layers/CompositorThread.h"
 
 namespace mozilla {
+using namespace layers;
 namespace gfx {
 
 VRLayerParent::VRLayerParent(uint32_t aVRDisplayID, const uint32_t aGroup)
@@ -62,17 +64,31 @@ VRLayerParent::RecvSubmitFrame(const layers::SurfaceDescriptor &aTexture,
                                const gfx::Rect& aRightEyeRect)
 {
   if (mVRDisplayID) {
+    MessageLoop* loop = layers::CompositorThreadHolder::Loop();
     VRManager* vm = VRManager::Get();
     RefPtr<VRDisplayHost> display = vm->GetDisplay(mVRDisplayID);
     if (display) {
-      display->SubmitFrame(this, aTexture, aFrameId,
-                           aLeftEyeRect, aRightEyeRect);
+      // Because VR compositor still shares the same graphics device with Compositor thread.
+      // We have to post sumbit frame tasks to Compositor thread.
+      // TODO: Move SubmitFrame to Bug 1392217.
+      loop->PostTask(NewRunnableMethod<VRDisplayHost*, const layers::SurfaceDescriptor, uint64_t,
+                                       const gfx::Rect&, const gfx::Rect&>(
+                     "gfx::VRLayerParent::SubmitFrame",
+                     this,
+                     &VRLayerParent::SubmitFrame, display, aTexture, aFrameId, aLeftEyeRect, aRightEyeRect));
     }
   }
 
   return IPC_OK();
 }
 
+void
+VRLayerParent::SubmitFrame(VRDisplayHost* aDisplay, const layers::SurfaceDescriptor& aTexture,
+                           uint64_t aFrameId, const gfx::Rect& aLeftEyeRect, const gfx::Rect& aRightEyeRect)
+{
+  aDisplay->SubmitFrame(this, aTexture, aFrameId,
+                        aLeftEyeRect, aRightEyeRect);
+}
 
 } // namespace gfx
 } // namespace mozilla
diff --git a/gfx/vr/ipc/VRLayerParent.h b/gfx/vr/ipc/VRLayerParent.h
index ec7fa78f3314..0239a1aaf69f 100644
--- a/gfx/vr/ipc/VRLayerParent.h
+++ b/gfx/vr/ipc/VRLayerParent.h
@@ -39,6 +39,10 @@ protected:
   gfx::Rect mLeftEyeRect;
   gfx::Rect mRightEyeRect;
   uint32_t mGroup;
+
+private:
+  void SubmitFrame(VRDisplayHost* aDisplay, const layers::SurfaceDescriptor& aTexture,
+                   uint64_t aFrameId, const gfx::Rect& aLeftEyeRect, const gfx::Rect& aRightEyeRect);
 };
 
 } // namespace gfx
diff --git a/gfx/vr/ipc/VRManagerChild.cpp b/gfx/vr/ipc/VRManagerChild.cpp
index 53caca4f7196..8972a0544166 100644
--- a/gfx/vr/ipc/VRManagerChild.cpp
+++ b/gfx/vr/ipc/VRManagerChild.cpp
@@ -7,6 +7,7 @@
 
 #include "VRManagerChild.h"
 #include "VRManagerParent.h"
+#include "VRThread.h"
 #include "VRDisplayClient.h"
 #include "nsGlobalWindow.h"
 #include "mozilla/StaticPtr.h"
@@ -119,7 +120,7 @@ VRManagerChild::InitSameProcess()
   sVRManagerChildSingleton = new VRManagerChild();
   sVRManagerParentSingleton = VRManagerParent::CreateSameProcess();
   sVRManagerChildSingleton->Open(sVRManagerParentSingleton->GetIPCChannel(),
-                                 mozilla::layers::CompositorThreadHolder::Loop(),
+                                 VRListenerThreadHolder::Loop(),
                                  mozilla::ipc::ChildSide);
 }
 
diff --git a/gfx/vr/ipc/VRManagerParent.cpp b/gfx/vr/ipc/VRManagerParent.cpp
index 64d4487def00..a8a5d51a3146 100644
--- a/gfx/vr/ipc/VRManagerParent.cpp
+++ b/gfx/vr/ipc/VRManagerParent.cpp
@@ -11,9 +11,9 @@
 #include "mozilla/ipc/ProtocolTypes.h"
 #include "mozilla/ipc/ProtocolUtils.h"       // for IToplevelProtocol
 #include "mozilla/TimeStamp.h"               // for TimeStamp
-#include "mozilla/layers/CompositorThread.h"
 #include "mozilla/Unused.h"
 #include "VRManager.h"
+#include "VRThread.h"
 #include "gfxVRPuppet.h"
 
 namespace mozilla {
@@ -87,7 +87,7 @@ VRManagerParent::UnregisterFromManager()
 /* static */ bool
 VRManagerParent::CreateForContent(Endpoint<PVRManagerParent>&& aEndpoint)
 {
-  MessageLoop* loop = layers::CompositorThreadHolder::Loop();
+  MessageLoop* loop = VRListenerThreadHolder::Loop();
 
   RefPtr<VRManagerParent> vmp = new VRManagerParent(aEndpoint.OtherPid(), true);
   loop->PostTask(NewRunnableMethod<Endpoint<PVRManagerParent>&&>(
@@ -111,7 +111,7 @@ VRManagerParent::Bind(Endpoint<PVRManagerParent>&& aEndpoint)
 }
 
 /*static*/ void
-VRManagerParent::RegisterVRManagerInCompositorThread(VRManagerParent* aVRManager)
+VRManagerParent::RegisterVRManagerInVRListenerThread(VRManagerParent* aVRManager)
 {
   aVRManager->RegisterWithManager();
 }
@@ -119,21 +119,21 @@ VRManagerParent::RegisterVRManagerInCompositorThread(VRManagerParent* aVRManager
 /*static*/ VRManagerParent*
 VRManagerParent::CreateSameProcess()
 {
-  MessageLoop* loop = mozilla::layers::CompositorThreadHolder::Loop();
+  MessageLoop* loop = VRListenerThreadHolder::Loop();
   RefPtr<VRManagerParent> vmp = new VRManagerParent(base::GetCurrentProcId(), false);
-  vmp->mCompositorThreadHolder = layers::CompositorThreadHolder::GetSingleton();
+  vmp->mVRListenerThreadHolder = VRListenerThreadHolder::GetSingleton();
   vmp->mSelfRef = vmp;
-  loop->PostTask(NewRunnableFunction(RegisterVRManagerInCompositorThread, vmp.get()));
+  loop->PostTask(NewRunnableFunction(RegisterVRManagerInVRListenerThread, vmp.get()));
   return vmp.get();
 }
 
 bool
 VRManagerParent::CreateForGPUProcess(Endpoint<PVRManagerParent>&& aEndpoint)
 {
-  MessageLoop* loop = mozilla::layers::CompositorThreadHolder::Loop();
+  MessageLoop* loop = VRListenerThreadHolder::Loop();
 
   RefPtr<VRManagerParent> vmp = new VRManagerParent(aEndpoint.OtherPid(), false);
-  vmp->mCompositorThreadHolder = layers::CompositorThreadHolder::GetSingleton();
+  vmp->mVRListenerThreadHolder = VRListenerThreadHolder::GetSingleton();
   loop->PostTask(NewRunnableMethod<Endpoint<PVRManagerParent>&&>(
     "gfx::VRManagerParent::Bind",
     vmp,
@@ -145,7 +145,7 @@ VRManagerParent::CreateForGPUProcess(Endpoint<PVRManagerParent>&& aEndpoint)
 void
 VRManagerParent::DeferredDestroy()
 {
-  mCompositorThreadHolder = nullptr;
+  mVRListenerThreadHolder = nullptr;
   mSelfRef = nullptr;
 }
 
@@ -162,12 +162,15 @@ VRManagerParent::ActorDestroy(ActorDestroyReason why)
 void
 VRManagerParent::OnChannelConnected(int32_t aPid)
 {
-  mCompositorThreadHolder = layers::CompositorThreadHolder::GetSingleton();
+  mVRListenerThreadHolder = VRListenerThreadHolder::GetSingleton();
 }
 
 mozilla::ipc::IPCResult
 VRManagerParent::RecvRefreshDisplays()
 {
+  // TODO: Bug 1406327, Launch VR listener thread here.
+  MOZ_ASSERT(VRListenerThreadHolder::IsInVRListenerThread());
+
   // This is called to refresh the VR Displays for Navigator.GetVRDevices().
   // We must pass "true" to VRManager::RefreshVRDisplays()
   // to ensure that the promise returned by Navigator.GetVRDevices
diff --git a/gfx/vr/ipc/VRManagerParent.h b/gfx/vr/ipc/VRManagerParent.h
index 92814abf0452..5e51ae6d7f95 100644
--- a/gfx/vr/ipc/VRManagerParent.h
+++ b/gfx/vr/ipc/VRManagerParent.h
@@ -8,13 +8,13 @@
 #ifndef MOZILLA_GFX_VR_VRMANAGERPARENT_H
 #define MOZILLA_GFX_VR_VRMANAGERPARENT_H
 
-#include "mozilla/layers/CompositableTransactionParent.h"
-#include "mozilla/layers/CompositorThread.h" // for CompositorThreadHolder
+#include "mozilla/layers/CompositableTransactionParent.h"  // need?
 #include "mozilla/gfx/PVRManagerParent.h" // for PVRManagerParent
 #include "mozilla/gfx/PVRLayerParent.h"   // for PVRLayerParent
 #include "mozilla/ipc/ProtocolUtils.h"    // for IToplevelProtocol
 #include "mozilla/TimeStamp.h"            // for TimeStamp
 #include "gfxVR.h"                        // for VRFieldOfView
+#include "VRThread.h"                     // for VRListenerThreadHolder
 
 namespace mozilla {
 using namespace layers;
@@ -81,16 +81,14 @@ private:
 
   void Bind(Endpoint<PVRManagerParent>&& aEndpoint);
 
-  static void RegisterVRManagerInCompositorThread(VRManagerParent* aVRManager);
+  static void RegisterVRManagerInVRListenerThread(VRManagerParent* aVRManager);
 
   void DeferredDestroy();
 
   // This keeps us alive until ActorDestroy(), at which point we do a
   // deferred destruction of ourselves.
   RefPtr<VRManagerParent> mSelfRef;
-
-  // Keep the compositor thread alive, until we have destroyed ourselves.
-  RefPtr<layers::CompositorThreadHolder> mCompositorThreadHolder;
+  RefPtr<VRListenerThreadHolder> mVRListenerThreadHolder;
 
   // Keep the VRManager alive, until we have destroyed ourselves.
   RefPtr<VRManager> mVRManagerHolder;
diff --git a/gfx/vr/moz.build b/gfx/vr/moz.build
index 5fb120f210af..a973f0c60344 100644
--- a/gfx/vr/moz.build
+++ b/gfx/vr/moz.build
@@ -13,6 +13,7 @@ EXPORTS += [
     'VRDisplayClient.h',
     'VRDisplayPresentation.h',
     'VRManager.h',
+    'VRThread.h',
 ]
 
 LOCAL_INCLUDES += [
@@ -31,6 +32,7 @@ UNIFIED_SOURCES += [
     'VRDisplayClient.cpp',
     'VRDisplayPresentation.cpp',
     'VRManager.cpp',
+    'VRThread.cpp',
 ]
 
 # VRDisplayHost includes MacIOSurface.h which includes Mac headers
diff --git a/js/src/jit/StupidAllocator.cpp b/js/src/jit/StupidAllocator.cpp
index a7d7abac6f8d..65a6b7ccad82 100644
--- a/js/src/jit/StupidAllocator.cpp
+++ b/js/src/jit/StupidAllocator.cpp
@@ -408,7 +408,6 @@ StupidAllocator::allocateForDefinition(LInstruction* ins, LDefinition* def)
 {
     uint32_t vreg = def->virtualRegister();
 
-    CodePosition from;
     if ((def->output()->isRegister() && def->policy() == LDefinition::FIXED) ||
         def->policy() == LDefinition::MUST_REUSE_INPUT)
     {
diff --git a/layout/base/crashtests/crashtests.list b/layout/base/crashtests/crashtests.list
index ff380962851c..4f662070c751 100644
--- a/layout/base/crashtests/crashtests.list
+++ b/layout/base/crashtests/crashtests.list
@@ -70,8 +70,8 @@ load 317934-1.html
 load 320459-1.html
 load 321058-1.xul
 load 321058-2.xul
-load 321077-1.xul
-load 321077-2.xul
+asserts-if(stylo,3) load 321077-1.xul # bug 1397644
+asserts-if(stylo,3) load 321077-2.xul # bug 1397644
 load 322436-1.html
 load 325967-1.html
 load 325984-1.xhtml
diff --git a/layout/base/nsCSSFrameConstructor.cpp b/layout/base/nsCSSFrameConstructor.cpp
index 7780270b5945..40f60686a4a7 100644
--- a/layout/base/nsCSSFrameConstructor.cpp
+++ b/layout/base/nsCSSFrameConstructor.cpp
@@ -5297,7 +5297,6 @@ nsCSSFrameConstructor::FlushAccumulatedBlock(nsFrameConstructorState& aState,
   // is not a suitable block.
   nsContainerFrame* blockFrame =
     NS_NewMathMLmathBlockFrame(mPresShell, blockContext);
-  blockFrame->AddStateBits(NS_BLOCK_FORMATTING_CONTEXT_STATE_BITS);
 
   InitAndRestoreFrame(aState, aContent, aParentFrame, blockFrame);
   ReparentFrames(this, blockFrame, aBlockItems, false);
diff --git a/layout/base/nsPresContext.cpp b/layout/base/nsPresContext.cpp
index 672e9d4fb95a..4f9de401df25 100644
--- a/layout/base/nsPresContext.cpp
+++ b/layout/base/nsPresContext.cpp
@@ -95,6 +95,7 @@
 #include "nsBidi.h"
 
 #include "mozilla/dom/URL.h"
+#include "mozilla/ServoCSSParser.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
@@ -146,17 +147,29 @@ private:
 nscolor
 nsPresContext::MakeColorPref(const nsString& aColor)
 {
-  nsCSSParser parser;
-  nsCSSValue value;
-  if (!parser.ParseColorString(aColor, nullptr, 0, value)) {
-    // Any better choices?
-    return NS_RGB(0, 0, 0);
+  bool ok;
+  nscolor result;
+
+  ServoStyleSet* servoStyleSet = mShell && mShell->StyleSet()
+    ? mShell->StyleSet()->GetAsServo()
+    : nullptr;
+
+  if (servoStyleSet) {
+    ok = ServoCSSParser::ComputeColor(servoStyleSet, NS_RGB(0, 0, 0), aColor,
+                                      &result);
+  } else {
+    nsCSSParser parser;
+    nsCSSValue value;
+    ok = parser.ParseColorString(aColor, nullptr, 0, value) &&
+         nsRuleNode::ComputeColor(value, this, nullptr, result);
   }
 
-  nscolor color;
-  return nsRuleNode::ComputeColor(value, this, nullptr, color)
-    ? color
-    : NS_RGB(0, 0, 0);
+  if (!ok) {
+    // Any better choices?
+    result = NS_RGB(0, 0, 0);
+  }
+
+  return result;
 }
 
 bool
@@ -1356,7 +1369,10 @@ nsPresContext::UpdateEffectiveTextZoom()
 
   mEffectiveTextZoom = newZoom;
 
-  if (HasCachedStyleData()) {
+  // In case of servo, stylist.device might have already generated the default
+  // computed values with the previous effective text zoom value even if the
+  // pres shell has not initialized yet.
+  if (mDocument->IsStyledByServo() || HasCachedStyleData()) {
     // Media queries could have changed, since we changed the meaning
     // of 'em' units in them.
     MediaFeatureValuesChanged(eRestyle_ForceDescendants,
diff --git a/layout/base/tests/marionette/test_accessiblecaret_selection_mode.py b/layout/base/tests/marionette/test_accessiblecaret_selection_mode.py
index 96c43886ead6..872e2d80e7b5 100644
--- a/layout/base/tests/marionette/test_accessiblecaret_selection_mode.py
+++ b/layout/base/tests/marionette/test_accessiblecaret_selection_mode.py
@@ -263,7 +263,7 @@ class AccessibleCaretSelectionModeTestCase(MarionetteTestCase):
         el = self.marionette.find_element(By.ID, el_id)
         self._test_minimum_select_one_character(el)
 
-    def _test_minimum_select_one_character(self, el, x=None, y=None):
+    def _test_minimum_select_one_character(self, el):
         sel = SelectionManager(el)
         original_content = sel.content
         words = original_content.split()
@@ -278,13 +278,7 @@ class AccessibleCaretSelectionModeTestCase(MarionetteTestCase):
         # Goal: Select the first character.
         target_content = original_content[0]
 
-        if x and y:
-            # If we got x and y from the arguments, use it as a hint of the
-            # location of the first word
-            pass
-        else:
-            x, y = self.word_location(el, 0)
-        self.long_press_on_location(el, x, y)
+        self.long_press_on_word(el, 0)
 
         # Drag the second caret to the end of the content.
         (caret1_x, caret1_y), (caret2_x, caret2_y) = sel.carets_location()
@@ -321,24 +315,26 @@ class AccessibleCaretSelectionModeTestCase(MarionetteTestCase):
     @parameterized(_content_id + '_to_' + _contenteditable_id,
                    el1_id=_content_id, el2_id=_contenteditable_id)
     def test_long_press_changes_focus_from(self, el1_id, el2_id):
-        '''Test the focus could be changed from el1 to el2 by long press.
+        self.open_test_html(self._selection_html)
+        el1 = self.marionette.find_element(By.ID, el1_id)
+        el2 = self.marionette.find_element(By.ID, el2_id)
 
-        If the focus is changed to e2 successfully, the carets should appear and
-        could be dragged.
+        # Compute the content of the first word in el2.
+        sel = SelectionManager(el2)
+        original_content = sel.content
+        words = original_content.split()
+        target_content = words[0]
 
-        '''
-        # Goal: Tap to focus el1, and then select the first character on
-        # el2.
+        # Goal: Tap to focus el1, and then select the first word on el2.
 
         # We want to collect the location of the first word in el2 here
         # since self.word_location() has the side effect which would
         # change the focus.
-        self.open_test_html(self._selection_html)
-        el1 = self.marionette.find_element(By.ID, el1_id)
-        el2 = self.marionette.find_element(By.ID, el2_id)
         x, y = self.word_location(el2, 0)
+
         el1.tap()
-        self._test_minimum_select_one_character(el2, x=x, y=y)
+        self.long_press_on_location(el2, x, y)
+        self.assertEqual(target_content, sel.selected_content)
 
     @parameterized(_input_id, el_id=_input_id)
     @parameterized(_textarea_id, el_id=_textarea_id)
diff --git a/layout/build/nsLayoutStatics.cpp b/layout/build/nsLayoutStatics.cpp
index 7bde5f45af6f..36eb2aae0a09 100644
--- a/layout/build/nsLayoutStatics.cpp
+++ b/layout/build/nsLayoutStatics.cpp
@@ -116,7 +116,6 @@
 #include "mozilla/IMEStateManager.h"
 #include "mozilla/dom/HTMLVideoElement.h"
 #include "TouchManager.h"
-#include "MediaDecoder.h"
 #include "MediaPrefs.h"
 #include "mozilla/ServoBindings.h"
 #include "mozilla/StaticPresData.h"
@@ -296,8 +295,6 @@ nsLayoutStatics::Initialize()
   mozilla::LayerAnimationInfo::Initialize();
 #endif
 
-  MediaDecoder::InitStatics();
-
   PromiseDebugging::Init();
 
   mozilla::dom::WebCryptoThreadPool::Initialize();
diff --git a/layout/inspector/inDOMUtils.cpp b/layout/inspector/inDOMUtils.cpp
index 4ae04620d8d6..770efc9e30df 100644
--- a/layout/inspector/inDOMUtils.cpp
+++ b/layout/inspector/inDOMUtils.cpp
@@ -52,6 +52,7 @@
 #include "mozilla/ServoBindings.h"
 #include "mozilla/ServoStyleRule.h"
 #include "mozilla/ServoStyleRuleMap.h"
+#include "mozilla/ServoCSSParser.h"
 
 using namespace mozilla;
 using namespace mozilla::css;
@@ -1006,19 +1007,25 @@ NS_IMETHODIMP
 inDOMUtils::ColorToRGBA(const nsAString& aColorString, JSContext* aCx,
                         JS::MutableHandle<JS::Value> aValue)
 {
-  nscolor color = 0;
+  nscolor color = NS_RGB(0, 0, 0);
+
+#ifdef MOZ_STYLO
+  if (!ServoCSSParser::ComputeColor(nullptr, NS_RGB(0, 0, 0), aColorString,
+                                    &color)) {
+    aValue.setNull();
+    return NS_OK;
+  }
+#else
   nsCSSParser cssParser;
   nsCSSValue cssValue;
 
-  bool isColor = cssParser.ParseColorString(aColorString, nullptr, 0,
-                                            cssValue, true);
-
-  if (!isColor) {
+  if (!cssParser.ParseColorString(aColorString, nullptr, 0, cssValue, true)) {
     aValue.setNull();
     return NS_OK;
   }
 
   nsRuleNode::ComputeColor(cssValue, nullptr, nullptr, color);
+#endif
 
   InspectorRGBATuple tuple;
   tuple.mR = NS_GET_R(color);
@@ -1036,34 +1043,13 @@ inDOMUtils::ColorToRGBA(const nsAString& aColorString, JSContext* aCx,
 NS_IMETHODIMP
 inDOMUtils::IsValidCSSColor(const nsAString& aColorString, bool *_retval)
 {
+#ifdef MOZ_STYLO
+  *_retval = ServoCSSParser::IsValidCSSColor(aColorString);
+#else
   nsCSSParser cssParser;
   nsCSSValue cssValue;
   *_retval = cssParser.ParseColorString(aColorString, nullptr, 0, cssValue, true);
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-inDOMUtils::CssPropertyIsValid(const nsAString& aPropertyName,
-                               const nsAString& aPropertyValue,
-                               bool *_retval)
-{
-  nsCSSPropertyID propertyID = nsCSSProps::
-    LookupProperty(aPropertyName, CSSEnabledState::eIgnoreEnabledState);
-
-  if (propertyID == eCSSProperty_UNKNOWN) {
-    *_retval = false;
-    return NS_OK;
-  }
-
-  if (propertyID == eCSSPropertyExtra_variable) {
-    *_retval = true;
-    return NS_OK;
-  }
-
-  // Get a parser, parse the property.
-  nsCSSParser parser;
-  *_retval = parser.IsValueValidForProperty(propertyID, aPropertyValue);
-
+#endif
   return NS_OK;
 }
 
diff --git a/layout/inspector/inIDOMUtils.idl b/layout/inspector/inIDOMUtils.idl
index 33cef0875b91..b2f47b3a095e 100644
--- a/layout/inspector/inIDOMUtils.idl
+++ b/layout/inspector/inIDOMUtils.idl
@@ -110,12 +110,6 @@ interface inIDOMUtils : nsISupports
 
   // Utilities for obtaining information about a CSS property.
 
-  // Check whether a CSS property and value are a valid combination. If the
-  // property is pref-disabled it will still be processed.
-  // aPropertyName: A property name e.g. "color"
-  // aPropertyValue: A property value e.g. "red" or "red !important"
-  bool cssPropertyIsValid(in AString aPropertyName, in AString aPropertyValue);
-
   // Get a list of the longhands corresponding to the given CSS property.  If
   // the property is a longhand already, just returns the property itself.
   // Throws on unsupported property names.
diff --git a/layout/inspector/tests/mochitest.ini b/layout/inspector/tests/mochitest.ini
index b99650fef7ae..26ff4951fb7a 100644
--- a/layout/inspector/tests/mochitest.ini
+++ b/layout/inspector/tests/mochitest.ini
@@ -18,7 +18,6 @@ support-files =
 [test_bug1006595.html]
 [test_color_to_rgba.html]
 [test_css_property_is_shorthand.html]
-[test_css_property_is_valid.html]
 [test_getCSSStyleRules.html]
 support-files =
   file_getCSSStyleRules-default.html
diff --git a/layout/inspector/tests/test_css_property_is_valid.html b/layout/inspector/tests/test_css_property_is_valid.html
deleted file mode 100644
index 798295d28384..000000000000
--- a/layout/inspector/tests/test_css_property_is_valid.html
+++ /dev/null
@@ -1,105 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<head>
-  <meta charset="utf-8">
-  <title>Test inDOMUtils::CssPropertyIsValid</title>
-  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
-  <script type="application/javascript">
-  let utils = SpecialPowers.Cc["@mozilla.org/inspector/dom-utils;1"]
-                           .getService(SpecialPowers.Ci.inIDOMUtils);
-
-  let tests = [
-    {
-      property: "color",
-      value: "red",
-      expected: true
-    },
-    {
-      property: "display",
-      value: "none",
-      expected: true
-    },
-    {
-      property: "display",
-      value: "red",
-      expected: false
-    },
-    {
-      property: "displayx",
-      value: "none",
-      expected: false
-    },
-    {
-      property: "border",
-      value: "1px solid blue",
-      expected: true
-    },
-    {
-      property: "border",
-      value: "1 solid blue",
-      expected: false
-    },
-    {
-      property: "border",
-      value: "1px underline blue",
-      expected: false
-    },
-    {
-      property: "border",
-      value: "1px solid",
-      expected: true
-    },
-    {
-      property: "color",
-      value: "blue !important",
-      expected: true
-    },
-    {
-      property: "color",
-      value: "blue ! important",
-      expected: true
-    },
-    {
-      property: "color",
-      value: "blue !impoxxxrtant",
-      expected: false
-    },
-    {
-      property: "color",
-      value: "red; background:green;",
-      expected: false
-    },
-    {
-      property: "content",
-      value: "\"hello\"",
-      expected: true
-    },
-    {
-      property: "color",
-      value: "var(--some-kind-of-green)",
-      expected: true
-    }
-  ];
-
-  for (let {property, value, expected} of tests) {
-    let valid = utils.cssPropertyIsValid(property, value);
-
-    if (expected) {
-      ok(valid, property + ":" + value + " is valid");
-    } else {
-      ok(!valid, property + ":" + value + " is not valid");
-    }
-  }
-  </script>
-</head>
-<body>
-<h1>Test inDOMUtils::CssPropertyIsValid</h1>
-<p id="display"></p>
-<div id="content" style="display: none">
-
-</div>
-<pre id="test">
-</pre>
-</body>
-</html>
diff --git a/layout/mathml/crashtests/1373767-1.html b/layout/mathml/crashtests/1373767-1.html
new file mode 100644
index 000000000000..9f3bfd398b1b
--- /dev/null
+++ b/layout/mathml/crashtests/1373767-1.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="UTF-8">
+<style>
+math {
+  position: fixed;
+}
+div {
+  transform: translateZ(0px);
+}
+body {
+  display: -moz-grid;
+}
+</style>
+</head>
+<body>
+<div>
+<math></math>
+</div>
+</body>
+</html>
diff --git a/layout/mathml/crashtests/crashtests.list b/layout/mathml/crashtests/crashtests.list
index add42f2bd787..4138c1f51c34 100644
--- a/layout/mathml/crashtests/crashtests.list
+++ b/layout/mathml/crashtests/crashtests.list
@@ -65,4 +65,5 @@ load 947557-1.html
 load 973322-1.xhtml
 load 1028521-1.xhtml
 load 1061027.html
+load 1373767-1.html
 load 1376158.html
diff --git a/layout/mathml/nsMathMLContainerFrame.cpp b/layout/mathml/nsMathMLContainerFrame.cpp
index 3d4e8d2311e0..b502771edcab 100644
--- a/layout/mathml/nsMathMLContainerFrame.cpp
+++ b/layout/mathml/nsMathMLContainerFrame.cpp
@@ -1549,7 +1549,9 @@ nsMathMLContainerFrame::ReportInvalidChildError(nsAtom* aChildTag)
 nsContainerFrame*
 NS_NewMathMLmathBlockFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 {
-  return new (aPresShell) nsMathMLmathBlockFrame(aContext);
+  auto newFrame = new (aPresShell) nsMathMLmathBlockFrame(aContext);
+  newFrame->AddStateBits(NS_BLOCK_FORMATTING_CONTEXT_STATE_BITS);
+  return newFrame;
 }
 
 NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmathBlockFrame)
diff --git a/layout/printing/DrawEventRecorder.cpp b/layout/printing/DrawEventRecorder.cpp
new file mode 100644
index 000000000000..55bd30ddcfc6
--- /dev/null
+++ b/layout/printing/DrawEventRecorder.cpp
@@ -0,0 +1,58 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "DrawEventRecorder.h"
+
+namespace mozilla {
+namespace layout {
+
+void
+DrawEventRecorderPRFileDesc::RecordEvent(const gfx::RecordedEvent& aEvent)
+{
+  WriteElement(mOutputStream, aEvent.GetType());
+
+  aEvent.RecordToStream(mOutputStream);
+
+  Flush();
+}
+
+DrawEventRecorderPRFileDesc::~DrawEventRecorderPRFileDesc()
+{
+  if (IsOpen()) {
+    Close();
+  }
+}
+
+void
+DrawEventRecorderPRFileDesc::Flush()
+{
+  mOutputStream.Flush();
+}
+
+bool
+DrawEventRecorderPRFileDesc::IsOpen()
+{
+  return mOutputStream.IsOpen();
+}
+
+void
+DrawEventRecorderPRFileDesc::OpenFD(PRFileDesc* aFd)
+{
+  MOZ_ASSERT(!IsOpen());
+
+  mOutputStream.OpenFD(aFd);
+  WriteHeader(mOutputStream);
+}
+
+void
+DrawEventRecorderPRFileDesc::Close()
+{
+  MOZ_ASSERT(IsOpen());
+
+  mOutputStream.Close();
+}
+
+}
+}
diff --git a/layout/printing/DrawEventRecorder.h b/layout/printing/DrawEventRecorder.h
new file mode 100644
index 000000000000..c30ad6da9ca0
--- /dev/null
+++ b/layout/printing/DrawEventRecorder.h
@@ -0,0 +1,104 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_layout_printing_DrawEventRecorder_h
+#define mozilla_layout_printing_DrawEventRecorder_h
+
+#include "mozilla/gfx/DrawEventRecorder.h"
+#include "mozilla/gfx/RecordingTypes.h"
+#include "prio.h"
+
+namespace mozilla {
+namespace layout {
+
+class PRFileDescStream : public mozilla::gfx::EventStream {
+public:
+  PRFileDescStream() : mFd(nullptr), mGood(true) {}
+
+  void OpenFD(PRFileDesc* aFd) {
+    MOZ_ASSERT(!IsOpen());
+    mFd = aFd;
+    mGood = true;
+  }
+
+  void Close() {
+    PR_Close(mFd);
+    mFd = nullptr;
+  }
+
+  bool IsOpen() {
+    return mFd != nullptr;
+  }
+
+  void Flush() {
+    // We need to be API compatible with std::ostream, and so we silently handle
+    // flushes on a closed FD.
+    if (IsOpen()) {
+      PR_Sync(mFd);
+    }
+  }
+
+  void Seek(PRInt32 aOffset, PRSeekWhence aWhence) {
+    PR_Seek(mFd, aOffset, aWhence);
+  }
+
+  void write(const char* aData, size_t aSize) {
+    // See comment in Flush().
+    if (IsOpen()) {
+      PR_Write(mFd, static_cast<const void*>(aData), aSize);
+    }
+  }
+
+  void read(char* aOut, size_t aSize) {
+    PRInt32 res = PR_Read(mFd, static_cast<void*>(aOut), aSize);
+    mGood = res >= 0 && ((size_t)res == aSize);
+  }
+
+  bool good() {
+    return mGood;
+  }
+
+private:
+  PRFileDesc* mFd;
+  bool mGood;
+};
+
+class DrawEventRecorderPRFileDesc : public gfx::DrawEventRecorderPrivate
+{
+public:
+  MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(DrawEventRecorderPRFileDesc, override)
+  explicit DrawEventRecorderPRFileDesc() { };
+  ~DrawEventRecorderPRFileDesc();
+
+  void RecordEvent(const gfx::RecordedEvent& aEvent) override;
+
+  /**
+   * Returns whether a recording file is currently open.
+   */
+  bool IsOpen();
+
+  /**
+   * Opens the recorder with the provided PRFileDesc *.
+   */
+  void OpenFD(PRFileDesc* aFd);
+
+  /**
+   * Closes the file so that it can be processed. The recorder does NOT forget
+   * which objects it has recorded. This can be used with OpenNew, so that a
+   * recording can be processed in chunks. The file must be open.
+   */
+  void Close();
+
+private:
+  void Flush() override;
+
+  PRFileDescStream mOutputStream;
+};
+
+}
+
+}
+
+#endif /* mozilla_layout_printing_DrawEventRecorder_h */
diff --git a/layout/printing/PrintTranslator.cpp b/layout/printing/PrintTranslator.cpp
index a2f1f5cbf7b5..168f9e81c3c7 100644
--- a/layout/printing/PrintTranslator.cpp
+++ b/layout/printing/PrintTranslator.cpp
@@ -25,7 +25,7 @@ PrintTranslator::PrintTranslator(nsDeviceContext* aDeviceContext)
 }
 
 bool
-PrintTranslator::TranslateRecording(std::istream& aRecording)
+PrintTranslator::TranslateRecording(PRFileDescStream& aRecording)
 {
   uint32_t magicInt;
   ReadElement(aRecording, magicInt);
diff --git a/layout/printing/PrintTranslator.h b/layout/printing/PrintTranslator.h
index 4558518ab74e..9ef079fcc877 100644
--- a/layout/printing/PrintTranslator.h
+++ b/layout/printing/PrintTranslator.h
@@ -35,7 +35,7 @@ class PrintTranslator final : public Translator
 public:
   explicit PrintTranslator(nsDeviceContext* aDeviceContext);
 
-  bool TranslateRecording(std::istream& aRecording);
+  bool TranslateRecording(PRFileDescStream& aRecording);
 
   DrawTarget* LookupDrawTarget(ReferencePtr aRefPtr) final
   {
diff --git a/layout/printing/ipc/PRemotePrintJob.ipdl b/layout/printing/ipc/PRemotePrintJob.ipdl
index f6c1de89573a..68280bd87981 100644
--- a/layout/printing/ipc/PRemotePrintJob.ipdl
+++ b/layout/printing/ipc/PRemotePrintJob.ipdl
@@ -22,9 +22,9 @@ parent:
   async InitializePrint(nsString aDocumentTitle, nsString aPrintToFile,
                         int32_t aStartPage, int32_t aEndPage);
 
-  // Translate the stored page recording and play back the events to the real
-  // print device.
-  async ProcessPage(nsCString aPageFileName);
+  // Translate the page recording writen into |fd| and play back the events to
+  // the real print device.
+  async ProcessPage();
 
   // This informs the real print device that we've finished, so it can trigger
   // the actual print.
@@ -45,11 +45,13 @@ parent:
 
 child:
   // Inform the child that the print has been initialized in the parent or has
-  // failed with result aRv.
-  async PrintInitializationResult(nsresult aRv);
+  // failed with result aRv. Includes a file descriptor which the first page
+  // can be written to.
+  async PrintInitializationResult(nsresult aRv, FileDescriptor aFd);
 
-  // Inform the child that the latest page has been processed remotely.
-  async PageProcessed();
+  // Inform the child that the latest page has been processed remotely. Inclues
+  // a file descriptor which the next page can be written to.
+  async PageProcessed(FileDescriptor aFd);
 
   async __delete__();
 };
diff --git a/layout/printing/ipc/RemotePrintJobChild.cpp b/layout/printing/ipc/RemotePrintJobChild.cpp
index 46cab20666c6..a8dbebe370c7 100644
--- a/layout/printing/ipc/RemotePrintJobChild.cpp
+++ b/layout/printing/ipc/RemotePrintJobChild.cpp
@@ -9,6 +9,7 @@
 #include "mozilla/Unused.h"
 #include "nsPagePrintTimer.h"
 #include "nsPrintEngine.h"
+#include "private/pprio.h"
 
 namespace mozilla {
 namespace layout {
@@ -36,26 +37,37 @@ RemotePrintJobChild::InitializePrint(const nsString& aDocumentTitle,
 }
 
 mozilla::ipc::IPCResult
-RemotePrintJobChild::RecvPrintInitializationResult(const nsresult& aRv)
+RemotePrintJobChild::RecvPrintInitializationResult(const nsresult& aRv,
+                                                   const mozilla::ipc::FileDescriptor& aFd)
 {
   mPrintInitialized = true;
   mInitializationResult = aRv;
+  if (NS_SUCCEEDED(aRv)) {
+    SetNextPageFD(aFd);
+  }
   return IPC_OK();
 }
 
+void RemotePrintJobChild::SetNextPageFD(const mozilla::ipc::FileDescriptor& aFd)
+{
+  auto handle = aFd.ClonePlatformHandle();
+  mNextPageFD = PR_ImportFile(PROsfd(handle.release()));
+}
+
 void
-RemotePrintJobChild::ProcessPage(const nsCString& aPageFileName)
+RemotePrintJobChild::ProcessPage()
 {
   MOZ_ASSERT(mPagePrintTimer);
 
   mPagePrintTimer->WaitForRemotePrint();
-  Unused << SendProcessPage(aPageFileName);
+  Unused << SendProcessPage();
 }
 
 mozilla::ipc::IPCResult
-RemotePrintJobChild::RecvPageProcessed()
+RemotePrintJobChild::RecvPageProcessed(const mozilla::ipc::FileDescriptor& aFd)
 {
   MOZ_ASSERT(mPagePrintTimer);
+  SetNextPageFD(aFd);
 
   mPagePrintTimer->RemotePrintFinished();
   return IPC_OK();
diff --git a/layout/printing/ipc/RemotePrintJobChild.h b/layout/printing/ipc/RemotePrintJobChild.h
index 10bf8de9a26b..3abeaca80134 100644
--- a/layout/printing/ipc/RemotePrintJobChild.h
+++ b/layout/printing/ipc/RemotePrintJobChild.h
@@ -34,11 +34,12 @@ public:
                            const int32_t& aStartPage,
                            const int32_t& aEndPage);
 
-  mozilla::ipc::IPCResult RecvPrintInitializationResult(const nsresult& aRv) final;
+  mozilla::ipc::IPCResult RecvPrintInitializationResult(const nsresult& aRv,
+                                                        const FileDescriptor& aFd) final;
 
-  void ProcessPage(const nsCString& aPageFileName);
+  void ProcessPage();
 
-  mozilla::ipc::IPCResult RecvPageProcessed() final;
+  mozilla::ipc::IPCResult RecvPageProcessed(const FileDescriptor& aFd) final;
 
   mozilla::ipc::IPCResult RecvAbortPrint(const nsresult& aRv) final;
 
@@ -46,13 +47,19 @@ public:
 
   void SetPrintEngine(nsPrintEngine* aPrintEngine);
 
+  PRFileDesc *GetNextPageFD() {
+    return mNextPageFD;
+  }
+
 private:
   ~RemotePrintJobChild() final;
+  void SetNextPageFD(const mozilla::ipc::FileDescriptor& aFd);
 
   bool mPrintInitialized = false;
   nsresult mInitializationResult = NS_OK;
   RefPtr<nsPagePrintTimer> mPagePrintTimer;
   RefPtr<nsPrintEngine> mPrintEngine;
+  PRFileDesc* mNextPageFD;
 };
 
 } // namespace layout
diff --git a/layout/printing/ipc/RemotePrintJobParent.cpp b/layout/printing/ipc/RemotePrintJobParent.cpp
index 46f47ed66dab..d82b14cbf11b 100644
--- a/layout/printing/ipc/RemotePrintJobParent.cpp
+++ b/layout/printing/ipc/RemotePrintJobParent.cpp
@@ -19,6 +19,8 @@
 #include "nsIPrintSettings.h"
 #include "nsIWebProgressListener.h"
 #include "PrintTranslator.h"
+#include "private/pprio.h"
+#include "nsAnonymousTemporaryFile.h"
 
 namespace mozilla {
 namespace layout {
@@ -38,14 +40,21 @@ RemotePrintJobParent::RecvInitializePrint(const nsString& aDocumentTitle,
   nsresult rv = InitializePrintDevice(aDocumentTitle, aPrintToFile, aStartPage,
                                       aEndPage);
   if (NS_FAILED(rv)) {
-    Unused << SendPrintInitializationResult(rv);
+    Unused << SendPrintInitializationResult(rv, FileDescriptor());
     Unused << Send__delete__(this);
     return IPC_OK();
   }
 
   mPrintTranslator.reset(new PrintTranslator(mPrintDeviceContext));
-  Unused << SendPrintInitializationResult(NS_OK);
+  FileDescriptor fd;
+  rv = PrepareNextPageFD(&fd);
+  if (NS_FAILED(rv)) {
+    Unused << SendPrintInitializationResult(rv, FileDescriptor());
+    Unused << Send__delete__(this);
+    return IPC_OK();
+  }
 
+  Unused << SendPrintInitializationResult(NS_OK, fd);
   return IPC_OK();
 }
 
@@ -82,22 +91,47 @@ RemotePrintJobParent::InitializePrintDevice(const nsString& aDocumentTitle,
   return NS_OK;
 }
 
+nsresult RemotePrintJobParent::PrepareNextPageFD(FileDescriptor* aFd) {
+  PRFileDesc *prFd = nullptr;
+  nsresult rv = NS_OpenAnonymousTemporaryFile(&prFd);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  *aFd = FileDescriptor(
+    FileDescriptor::PlatformHandleType(PR_FileDesc2NativeHandle(prFd)));
+  mCurrentPageStream.OpenFD(prFd);
+  return NS_OK;
+}
+
 mozilla::ipc::IPCResult
-RemotePrintJobParent::RecvProcessPage(const nsCString& aPageFileName)
+RemotePrintJobParent::RecvProcessPage()
 {
-  nsresult rv = PrintPage(aPageFileName);
+  if (!mCurrentPageStream.IsOpen()) {
+    Unused << SendAbortPrint(NS_ERROR_FAILURE);
+    return IPC_OK();
+  }
+  mCurrentPageStream.Seek(0, PR_SEEK_SET);
+  nsresult rv = PrintPage(mCurrentPageStream);
+  mCurrentPageStream.Close();
 
   if (NS_FAILED(rv)) {
     Unused << SendAbortPrint(rv);
-  } else {
-    Unused << SendPageProcessed();
+    return IPC_OK();
   }
 
+  FileDescriptor fd;
+  rv = PrepareNextPageFD(&fd);
+  if (NS_FAILED(rv)) {
+    Unused << SendAbortPrint(rv);
+    return IPC_OK();
+  }
+
+  Unused << SendPageProcessed(fd);
   return IPC_OK();
 }
 
 nsresult
-RemotePrintJobParent::PrintPage(const nsCString& aPageFileName)
+RemotePrintJobParent::PrintPage(PRFileDescStream& aRecording)
 {
   MOZ_ASSERT(mPrintDeviceContext);
 
@@ -105,27 +139,7 @@ RemotePrintJobParent::PrintPage(const nsCString& aPageFileName)
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
-
-  nsCOMPtr<nsIFile> recordingFile;
-  rv = NS_GetSpecialDirectory(NS_APP_CONTENT_PROCESS_TEMP_DIR,
-                              getter_AddRefs(recordingFile));
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  rv = recordingFile->AppendNative(aPageFileName);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  nsAutoCString recordingPath;
-  rv = recordingFile->GetNativePath(recordingPath);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  std::ifstream recording(recordingPath.get(), std::ifstream::binary);
-  if (!mPrintTranslator->TranslateRecording(recording)) {
+  if (!mPrintTranslator->TranslateRecording(aRecording)) {
     return NS_ERROR_FAILURE;
   }
 
@@ -134,12 +148,6 @@ RemotePrintJobParent::PrintPage(const nsCString& aPageFileName)
     return rv;
   }
 
-  recording.close();
-  rv = recordingFile->Remove(/* recursive= */ false);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
   return NS_OK;
 }
 
@@ -240,5 +248,3 @@ RemotePrintJobParent::ActorDestroy(ActorDestroyReason aWhy)
 
 } // namespace layout
 } // namespace mozilla
-
-
diff --git a/layout/printing/ipc/RemotePrintJobParent.h b/layout/printing/ipc/RemotePrintJobParent.h
index 0aa88bef1f55..6013374ac63b 100644
--- a/layout/printing/ipc/RemotePrintJobParent.h
+++ b/layout/printing/ipc/RemotePrintJobParent.h
@@ -8,11 +8,13 @@
 #define mozilla_layout_RemotePrintJobParent_h
 
 #include "mozilla/layout/PRemotePrintJobParent.h"
+#include "mozilla/layout/printing/DrawEventRecorder.h"
 
 #include "nsCOMArray.h"
 #include "nsCOMPtr.h"
 #include "mozilla/RefPtr.h"
 #include "mozilla/UniquePtr.h"
+#include "mozilla/gfx/RecordedEvent.h"
 
 class nsDeviceContext;
 class nsIPrintSettings;
@@ -34,7 +36,7 @@ public:
                                               const int32_t& aStartPage,
                                               const int32_t& aEndPage) final;
 
-  mozilla::ipc::IPCResult RecvProcessPage(const nsCString& aPageFileName) final;
+  mozilla::ipc::IPCResult RecvProcessPage() final;
 
   mozilla::ipc::IPCResult RecvFinalizePrint() final;
 
@@ -70,12 +72,15 @@ private:
                                  const int32_t& aStartPage,
                                  const int32_t& aEndPage);
 
-  nsresult PrintPage(const nsCString& aPageFileName);
+  nsresult PrepareNextPageFD(FileDescriptor* aFd);
+
+  nsresult PrintPage(PRFileDescStream& aRecording);
 
   nsCOMPtr<nsIPrintSettings> mPrintSettings;
   RefPtr<nsDeviceContext> mPrintDeviceContext;
   UniquePtr<PrintTranslator> mPrintTranslator;
   nsCOMArray<nsIWebProgressListener> mPrintProgressListeners;
+  PRFileDescStream mCurrentPageStream;
 };
 
 } // namespace layout
diff --git a/layout/printing/moz.build b/layout/printing/moz.build
index 1a82d7cdb392..5548da46bac6 100644
--- a/layout/printing/moz.build
+++ b/layout/printing/moz.build
@@ -15,9 +15,14 @@ EXPORTS.mozilla.layout += [
     'ipc/RemotePrintJobParent.h',
 ]
 
+EXPORTS.mozilla.layout.printing += [
+    'DrawEventRecorder.h'
+]
+
 XPIDL_MODULE = 'layout_printing'
 
 UNIFIED_SOURCES += [
+    'DrawEventRecorder.cpp',
     'ipc/RemotePrintJobChild.cpp',
     'ipc/RemotePrintJobParent.cpp',
     'nsPagePrintTimer.cpp',
@@ -34,4 +39,5 @@ FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '../base',
     '/dom/base',
+    '/gfx/2d/'
 ]
diff --git a/layout/printing/nsPagePrintTimer.cpp b/layout/printing/nsPagePrintTimer.cpp
index 61afd596be55..ff0b2dc588a9 100644
--- a/layout/printing/nsPagePrintTimer.cpp
+++ b/layout/printing/nsPagePrintTimer.cpp
@@ -156,7 +156,8 @@ nsPagePrintTimer::Notify(nsITimer *timer)
 
   if (mDocViewerPrint) {
     bool donePrePrint = true;
-    if (mPrintEngine) {
+    // Don't start to pre-print if we're waiting on the parent still.
+    if (mPrintEngine && !mWaitingForRemotePrint) {
       donePrePrint = mPrintEngine->PrePrintPage();
     }
 
diff --git a/layout/reftests/bidi/reftest.list b/layout/reftests/bidi/reftest.list
index 524259f9f479..2bf9b2227a0a 100644
--- a/layout/reftests/bidi/reftest.list
+++ b/layout/reftests/bidi/reftest.list
@@ -143,13 +143,13 @@ fuzzy-if(skiaContent,1,3) == 698291-1.html 698291-1-ref.html
 == 817406-3.html 817406-1-ref.html
 == 817406-4.html 817406-4-ref.html
 == 847242-1.html 847242-1-ref.html
-fuzzy-if(xulRuntime.widgetToolkit=="gtk3",1,11) == 869833-1.xul 869833-1-ref.xul
+fuzzy-if(xulRuntime.widgetToolkit=="gtk3",1,11) fails-if(stylo||styloVsGecko) asserts-if(stylo,24-26) == 869833-1.xul 869833-1-ref.xul # stylo: bug 1397644
 == 922530-1.html 922530-1-ref.html
 == 922550-1.html 922550-1-ref.html
 == 1067268-1.html 1067268-1-ref.html
 == 1069941-inline-bidi-border-1.html 1069941-inline-bidi-border-1-ref.html
 == 1069941-inline-bidi-margin-1.html 1069941-inline-bidi-margin-1-ref.html
-!= 1155359-1.xul 1155359-1-ref.xul
+fails-if(stylo||styloVsGecko) != 1155359-1.xul 1155359-1-ref.xul # bug 1408235
 == 1157726-1.html 1157726-1-ref.html
 == 1161752.html 1161752-ref.html
 == 1161752-5-embed.html 1161752-5-embed-ref.html
diff --git a/layout/reftests/box-ordinal/reftest.list b/layout/reftests/box-ordinal/reftest.list
index 91de0baaa8e2..e1c1e27263e0 100644
--- a/layout/reftests/box-ordinal/reftest.list
+++ b/layout/reftests/box-ordinal/reftest.list
@@ -1,7 +1,7 @@
 == box-ordinal-with-out-of-flow-1.html box-ordinal-with-out-of-flow-1-ref.html
 == dynamic-1-remove-to-none-grouped.xul dynamic-1-ref.xul
 == dynamic-1-add-to-one-grouped.xul dynamic-1-ref.xul
-== dynamic-1-remove-to-one-grouped-1.xul dynamic-1-ref.xul
+fails-if(stylo||styloVsGecko) == dynamic-1-remove-to-one-grouped-1.xul dynamic-1-ref.xul # bug 1408235
 fails == dynamic-1-remove-to-one-grouped-2.xul dynamic-1-ref.xul # bug 575500
-== dynamic-1-add-to-two-grouped-1.xul dynamic-1-ref.xul
-== dynamic-1-add-to-two-grouped-2.xul dynamic-1-ref.xul
+fails-if(stylo||styloVsGecko) == dynamic-1-add-to-two-grouped-1.xul dynamic-1-ref.xul # bug 1408235
+fails-if(stylo||styloVsGecko) == dynamic-1-add-to-two-grouped-2.xul dynamic-1-ref.xul # bug 1408235
diff --git a/layout/reftests/box-shadow/reftest.list b/layout/reftests/box-shadow/reftest.list
index 4b3324f06069..90369a950c21 100644
--- a/layout/reftests/box-shadow/reftest.list
+++ b/layout/reftests/box-shadow/reftest.list
@@ -18,7 +18,7 @@ fuzzy-if(skiaContent,13,28) fuzzy-if(webrender,29-29,453-453) == boxshadow-inner
 random-if(layersGPUAccelerated) == boxshadow-mixed.html boxshadow-mixed-ref.html
 == boxshadow-mixed-2.html boxshadow-mixed-2-ref.html
 random-if(d2d) fuzzy-if(skiaContent,1,100) fuzzy-if(webrender,127,3528) == boxshadow-rounded-spread.html boxshadow-rounded-spread-ref.html
-fuzzy-if(skiaContent,1,50) HTTP(..) == boxshadow-dynamic.xul boxshadow-dynamic-ref.xul
+fuzzy-if(skiaContent,1,50) fails-if(stylo) HTTP(..) == boxshadow-dynamic.xul boxshadow-dynamic-ref.xul # bug 1408235
 random-if(d2d) fails-if(webrender) == boxshadow-onecorner.html boxshadow-onecorner-ref.html
 random-if(d2d) fails-if(webrender) == boxshadow-twocorners.html boxshadow-twocorners-ref.html
 random-if(d2d) fails-if(webrender) == boxshadow-threecorners.html boxshadow-threecorners-ref.html
diff --git a/layout/reftests/bugs/reftest.list b/layout/reftests/bugs/reftest.list
index 394e237e0574..994296d9c238 100644
--- a/layout/reftests/bugs/reftest.list
+++ b/layout/reftests/bugs/reftest.list
@@ -165,26 +165,26 @@ random == 99850-1b.html 99850-1-ref.html # bug 471629
 == 192767-06.xul 192767-16.xul
 == 192767-07.xul 192767-17.xul
 == 192767-21.xul 192767-31.xul
-== 192767-22.xul 192767-32.xul
-== 192767-23.xul 192767-33.xul
-== 192767-24.xul 192767-34.xul
-== 192767-25.xul 192767-35.xul
-== 192767-26.xul 192767-36.xul
-== 192767-27.xul 192767-37.xul
+fails-if(styloVsGecko) == 192767-22.xul 192767-32.xul # bug 1408235
+fails-if(styloVsGecko) == 192767-23.xul 192767-33.xul # bug 1408235
+fails-if(styloVsGecko) == 192767-24.xul 192767-34.xul # bug 1408235
+fails-if(styloVsGecko) == 192767-25.xul 192767-35.xul # bug 1408235
+fails-if(styloVsGecko) == 192767-26.xul 192767-36.xul # bug 1408235
+fails-if(styloVsGecko) == 192767-27.xul 192767-37.xul # bug 1408235
 != 192767-01.xul 192767-21.xul
-!= 192767-02.xul 192767-22.xul
-fails-if(Android&&!asyncPan) != 192767-03.xul 192767-23.xul
-!= 192767-04.xul 192767-24.xul
-!= 192767-05.xul 192767-25.xul
-fails-if(Android&&!asyncPan) != 192767-06.xul 192767-26.xul
-fails-if(Android&&!asyncPan) != 192767-07.xul 192767-27.xul
+fails-if(stylo) != 192767-02.xul 192767-22.xul # bug 1408235
+fails-if(stylo||(Android&&!asyncPan)) != 192767-03.xul 192767-23.xul # bug 1408235 for stylo
+fails-if(stylo) != 192767-04.xul 192767-24.xul # bug 1408235
+fails-if(stylo) != 192767-05.xul 192767-25.xul # bug 1408235
+fails-if(stylo||(Android&&!asyncPan)) != 192767-06.xul 192767-26.xul # bug 1408235 for stylo
+fails-if(stylo||(Android&&!asyncPan)) != 192767-07.xul 192767-27.xul # bug 1408235 for stylo
 != 192767-11.xul 192767-31.xul
-!= 192767-12.xul 192767-32.xul
-fails-if(Android&&!asyncPan) != 192767-13.xul 192767-33.xul
-!= 192767-14.xul 192767-34.xul
-!= 192767-15.xul 192767-35.xul
-fails-if(Android&&!asyncPan) != 192767-16.xul 192767-36.xul
-fails-if(Android&&!asyncPan) != 192767-17.xul 192767-37.xul
+fails-if(stylo) != 192767-12.xul 192767-32.xul # bug 1408235
+fails-if(stylo||(Android&&!asyncPan)) != 192767-13.xul 192767-33.xul # bug 1408235 for stylo
+fails-if(stylo) != 192767-14.xul 192767-34.xul # bug 1408235
+fails-if(stylo) != 192767-15.xul 192767-35.xul # bug 1408235
+fails-if(stylo||(Android&&!asyncPan)) != 192767-16.xul 192767-36.xul # bug 1408235 for stylo
+fails-if(stylo||(Android&&!asyncPan)) != 192767-17.xul 192767-37.xul # bug 1408235 for stylo
 != 200774-1.html about:blank
 == 201215-1.html 201215-1-ref.html
 == 201293-1a.html 201293-1-ref.html
@@ -206,7 +206,7 @@ fuzzy-if(skiaContent,1,5) == 212563-2.html 212563-2-ref.html
 == 214077-1a.html 214077-1-ref.html
 == 214077-1b.html 214077-1-ref.html
 == 218473-1.html 218473-1-ref.html
-fuzzy-if(skiaContent,1,4) fuzzy-if(webrender&&debug,1,6) == 220165-1.svg 220165-1-ref.svg
+fuzzy-if(skiaContent,1,4) fuzzy-if(webrender&&debug,1,8) == 220165-1.svg 220165-1-ref.svg
 == 223809-1.html 223809-1-ref.html
 == 228856-1.html 228856-1-ref.html
 == 228856-2.html 228856-2-ref.html
@@ -273,13 +273,13 @@ skip-if(Android&&asyncPan) == 243519-1.html 243519-1-ref.html
 == 244135-2.html 244135-2-ref.html
 == 244932-1.html 244932-1-ref.html
 == 246669-1.html 246669-1-ref.html
-== 249141.xul 249141-ref.xul
+fails-if(stylo||styloVsGecko) == 249141.xul 249141-ref.xul # bug 1408235
 == 249982-1.html 249982-1-ref.html
 == 252920-1.html 252920-1-ref.html
 == 253701-1.html 253701-1-ref.html
 fuzzy-if(skiaContent,1,5) == 255820-1.html 255820-1-ref.html
 == 260406-1.html 260406-1-ref.html
-== 261826-1.xul 261826-1-ref.xul
+fails-if(styloVsGecko) == 261826-1.xul 261826-1-ref.xul # bug 1408824
 == 262151-1.html 262151-1-ref.html
 fuzzy-if(skiaContent,1,5) == 262998-1.html 262998-1-ref.html
 == 267353-1.html 267353-1-ref.html
@@ -290,10 +290,10 @@ fuzzy-if(skiaContent,1,5) == 262998-1.html 262998-1-ref.html
 == 269908-5.html 269908-5-ref.html
 == 271747-1a.html 271747-1-ref.html
 == 271747-1b.html 271747-1-ref.html
-== 272646-1.xul 272646-1-ref.xul
-== 272646-2a.xul 272646-2-ref.xul
-== 272646-2b.xul 272646-2-ref.xul
-== 272646-2c.xul 272646-2-ref.xul
+fails-if(stylo&&cocoaWidget) == 272646-1.xul 272646-1-ref.xul # bug 1408824
+fails-if(styloVsGecko) == 272646-2a.xul 272646-2-ref.xul # bug 1408824
+fails-if(styloVsGecko) == 272646-2b.xul 272646-2-ref.xul # bug 1408824
+fails-if(styloVsGecko) == 272646-2c.xul 272646-2-ref.xul # bug 1408824
 fuzzy-if(Android,3,50) fuzzy-if(skiaContent,1,133) == 273681-1.html 273681-1-ref.html
 == 278266-1a.html 278266-1-ref.html
 == 278266-1b.html 278266-1-ref.html
@@ -316,8 +316,8 @@ random-if(d2d) fuzzy-if(Android,8,1439) skip-if(styloVsGecko) fuzzy-if(webrender
 == 296904-1.html 296904-1-ref.html
 == 299136-1.html 299136-1-ref.html
 == 299837-1.html 299837-1-ref.html
-== 299837-2.xul 299837-2-ref.xul
-random-if(d2d) == 299837-3.xul 299837-3-ref.xul # bug 587631
+fails-if(styloVsGecko) == 299837-2.xul 299837-2-ref.xul # bug 1408235
+random-if(d2d) asserts-if(stylo,24-128) asserts-if(styloVsGecko,12-64) == 299837-3.xul 299837-3-ref.xul # bug 587631, stylo: bug 1397644
 == 300691-1a.html 300691-1-ref.html
 == 300691-1b.html 300691-1-ref.html
 == 300691-1c.html 300691-1-ref.html
@@ -339,7 +339,7 @@ fails-if(Android) != 301726-2.html 301726-2-ref.html
 == 308406-1.html 308406-1-ref.html
 == 308406-2.html 308406-2-ref.html
 == 309550-1.html 309550-1-ref.html
-== 309914-1.xul 309914-1-ref.xul
+fails-if(stylo||styloVsGecko) == 309914-1.xul 309914-1-ref.xul # bug 1408235
 == 311366-unknown-inline-1.html 311366-unknown-inline-1-ref.html
 == 311366-unknown-block-1.html 311366-unknown-block-1-ref.html
 == 311366-unknown-block-3.html 311366-unknown-block-3-ref.html
@@ -412,7 +412,7 @@ fuzzy-if(Android,2,18) == 315920-17.html 315920-17-ref.html
 == 320979-1.html 320979-1-ref.html
 != 321402-1.html about:blank
 != 321402-2.html about:blank
-== 321402-3.xul 321402-3-ref.xul
+fails-if(stylo&&!gtkWidget) == 321402-3.xul 321402-3-ref.xul # bug 1408235
 == 321402-4.xul 321402-4-ref.xul
 == 321402-5.xul 321402-5-ref.xul
 == 321402-6.xul 321402-6-ref.xul
@@ -442,8 +442,8 @@ random == 328829-1.xhtml 328829-1-ref.xhtml # bug 369046 (intermittent)
 == 334829-1a.xhtml 334829-1-ref.xhtml
 == 334829-1b.xhtml 334829-1-ref.xhtml
 == 335628-1.html 335628-1-ref.html
-!= 335628-2.xul 335628-2-ref.xul
-== 336096-1.xul 336096-1-ref.xul
+fails-if(stylo||styloVsGecko) != 335628-2.xul 335628-2-ref.xul # bug 1408235
+fails-if(stylo) == 336096-1.xul 336096-1-ref.xul # bug 1408235
 == 336147-1.html 336147-1-ref.html
 == 336153-1.html 336153-1-ref.html
 != 338251-p.html about:blank
@@ -567,11 +567,11 @@ fuzzy-if(OSX,45,2) fuzzy-if(winWidget,114,1) == 363858-6a.html 363858-6-ref.html
 == 364318-1.xhtml 364318-1-ref.xhtml
 == 364861-1.html 364861-1-ref.html
 == 364862-1.html 364862-1-ref.html
-== 364968-1.xul 364968-1-ref.html
+fails-if(stylo||styloVsGecko) == 364968-1.xul 364968-1-ref.html # bug 1408235
 == 364989-1.html 364989-1-ref.html
 == 365173-1.html 365173-1-ref.html
-== 366207-1.xul 366207-1-ref.xul
-== 366616-1.xul 366616-1-ref.xul
+fails-if(stylo||styloVsGecko) == 366207-1.xul 366207-1-ref.xul # bug 1408235
+fails-if(stylo) == 366616-1.xul 366616-1-ref.xul # bug 1408235
 == 367220-1.html 367220-1-ref.html
 == 367247-s-visible.html 367247-s-hidden.html
 == 367247-s-hidden.html 367247-s-auto.html
@@ -667,7 +667,7 @@ random-if(d2d) == 373381-3.html 373381-3-ref.html
 == 373533-3.xhtml about:blank
 == 374038-1.xul 374038-1-ref.xul
 == 374038-2.xul 374038-2-ref.xul
-random-if(d2d) == 374719-1.xul 374719-1-ref.xul
+random-if(d2d) fails-if(styloVsGecko) == 374719-1.xul 374719-1-ref.xul # bug 1408824
 fails == 374927-1.html 374927-1-ref.html # Was broken by patch for bug 368600; fails until bug 400776 is fixed
 == 375508-1.html 375508-1-ref.html
 == 375716-1.html 375716-1-ref.html
@@ -1002,7 +1002,7 @@ asserts(1) == 418574-2.html 418574-2-ref.html # bug 478135
 == 421069-ref.html 421069-ref2.html
 == 421203-1.xul 421203-1-ref.html
 == 421203-2.xul 421203-1-ref.html
-== 421203-3.xul 321402-3-ref.xul
+fails-if(stylo&&!gtkWidget) == 421203-3.xul 321402-3-ref.xul # bug 1408235
 == 421203-4.xul 321402-4-ref.xul
 == 421203-5.xul 321402-5-ref.xul
 == 421203-6.xul 321402-6-ref.xul
@@ -1182,7 +1182,7 @@ test-pref(dom.use_xbl_scopes_for_remote_xul,true) != 449149-1b.html about:blank
 == 449149-2.html 449149-2-ref.html
 == 449171-1.html 449171-ref.html
 == 449362-1.html 449362-1-ref.html
-fuzzy-if(webrender,3,360) == 449519-1.html 449519-1-ref.html
+fuzzy-if(webrender,4,361) == 449519-1.html 449519-1-ref.html
 == 450670-1.html 450670-1-ref.html
 == 451168-1.html 451168-1-ref.html
 == 451876-1.html 451876-1-ref.html
@@ -1233,7 +1233,7 @@ fuzzy-if(skiaContent,1,12000) fails-if(webrender) == 461512-1.html 461512-1-ref.
 == 462844-3.html 462844-ref.html
 == 462844-4.html 462844-ref.html
 == 463204-1.html 463204-1-ref.html
-fuzzy-if(webrender,16-16,3425-3425) == 463217-1.xul 463217-1-ref.xul
+fuzzy-if(webrender&&!stylo,16-16,3425-3425) fails-if(styloVsGecko) == 463217-1.xul 463217-1-ref.xul # bug 1408235
 == 463952-1.html 463952-1-ref.html
 == 464811-1.html 464811-1-ref.html
 == 465574-1.html 465574-1-ref.html # bug 421436
@@ -1244,7 +1244,7 @@ fuzzy-if(webrender,16-16,3425-3425) == 463217-1.xul 463217-1-ref.xul
 == 467084-2.html 467084-2-ref.html
 == 467444-1.html 467444-1-ref.html
 == 467460-1.html 467460-1-ref.html
-== 468473-1.xul 468473-1-ref.xul
+fails-if(styloVsGecko) == 468473-1.xul 468473-1-ref.xul # bug 1408235
 == 468546-1.xhtml 468546-1-ref.xhtml
 == 471356-1.html 471356-1-ref.html
 == 471594-1.xhtml 471594-1-ref.html
@@ -1256,7 +1256,7 @@ fails == 472020-2.xul 472020-2-ref.xul
 == 472769-1b.html 472769-1-ref.html
 == 472769-2.html 472769-2-ref.html
 == 472769-3.html 472769-3-ref.html
-== 473847-1.xul 473847-1-ref.xul
+fails-if(styloVsGecko) == 473847-1.xul 473847-1-ref.xul # bug 1408235
 fuzzy-if(skiaContent,1,16) == 474336-1.xul 474336-1-ref.xul
 == 474417-1.html 474417-1-ref.html
 fuzzy-if(skiaContent,1,5) skip-if((stylo||styloVsGecko)&&isDebugBuild&&winWidget) == 474472-1.html 474472-1-ref.html # Bug 1383845
@@ -1289,7 +1289,7 @@ fuzzy-if(skiaContent,1,5) skip-if((stylo||styloVsGecko)&&isDebugBuild&&winWidget
 == 476598-1b.html 476598-1-ref2.html
 != 476598-1-ref.html about:blank
 == 476856-1.html 476856-1-ref.html
-random-if(d2d) == 478377-1.xul 478377-1-ref.xul
+random-if(d2d) fails-if(styloVsGecko) asserts-if(stylo,16-18) == 478377-1.xul 478377-1-ref.xul # bug 1397644
 == 478614-1.html 478614-1-ref.html
 == 478614-2.html 478614-1-ref.html
 == 478614-3.html 478614-3-ref.html
@@ -1327,7 +1327,7 @@ random-if(winWidget) fuzzy-if(skiaContent,1,5) == 482659-1a.html 482659-1-ref.ht
 fuzzy-if(skiaContent,1,5) == 482659-1b.html 482659-1-ref.html
 fuzzy-if(skiaContent,1,5) == 482659-1c.html 482659-1-ref.html
 fuzzy-if(skiaContent,1,5) == 482659-1d.html 482659-1-ref.html
-== 483565.xul 483565-ref.xul
+fails-if(styloVsGecko) == 483565.xul 483565-ref.xul # bug 1408235
 == 484256-1.html 484256-1-ref.html
 == 484256-2.html 484256-1-ref.html
 == 485012-1.html 485012-1-ref.html
@@ -1342,7 +1342,7 @@ fuzzy-if(skiaContent,1,5) == 482659-1d.html 482659-1-ref.html
 == 486052-2f.html 486052-2-ref.html
 == 486052-2g.html 486052-2-ref.html
 == 486065-1.html 486065-1-ref.html
-== 486848-1.xul 486848-1-ref.xul
+skip-if(stylo||styloVsGecko) == 486848-1.xul 486848-1-ref.xul # bug 1408293
 == 487539-1.html about:blank
 == 488390-1.html 488390-1-ref.html
 == 488649-1.html 488649-1-ref.html
@@ -1358,7 +1358,7 @@ fuzzy-if(skiaContent,1,5) == 482659-1d.html 482659-1-ref.html
 pref(browser.display.focus_ring_width,1) == 491180-1.html 491180-1-ref.html
 pref(browser.display.focus_ring_width,1) == 491180-2.html 491180-2-ref.html
 == 491323-1.xul 491323-1-ref.xul
-== 492239-1.xul 492239-1-ref.xul
+fails-if(styloVsGecko) == 492239-1.xul 492239-1-ref.xul # bug 1408235
 == 492661-1.html 492661-1-ref.html
 == 493968-1.html 493968-1-ref.html
 == 494667-1.html 494667-1-ref.html
@@ -1411,7 +1411,7 @@ fuzzy-if(Android,5,2800) == 506481-1.html 506481-1-ref.html
 == 507762-2.html 507762-2-ref.html
 == 507762-3.html 507762-1-ref.html
 == 507762-4.html 507762-2-ref.html
-random-if(cocoaWidget||winWidget) == 508816-1.xul 508816-1-ref.xul # Bug 631982 and bug 1375012
+random-if(cocoaWidget||winWidget) fails-if(styloVsGecko) == 508816-1.xul 508816-1-ref.xul # Bug 631982 and bug 1375012, stylo: bug 1408235
 == 508816-2.html 508816-2-ref.html
 skip-if(isDebugBuild) == 508908-1.xul 508908-1-ref.xul
 == 508919-1.xhtml 508919-1-ref.xhtml
@@ -1422,8 +1422,8 @@ fuzzy-if(Android,5,1656) fuzzy-if(skiaContent,1,1200) == 512410.html 512410-ref.
 == 513153-1b.html 513153-1-ref.html
 == 513153-2a.html 513153-2-ref.html
 == 513153-2b.html 513153-2-ref.html
-== 513318-1.xul 513318-1-ref.xul
-fails-if(Android&&(!asyncPan)) != 513318-2.xul 513318-2-ref.xul
+fails-if(stylo||styloVsGecko) == 513318-1.xul 513318-1-ref.xul # bug 1408235
+fails-if(Android&&(!asyncPan)) fails-if(styloVsGecko) != 513318-2.xul 513318-2-ref.xul # stylo: bug 1408235
 == 514917-1.html 514917-1-ref.html
 HTTP(..) == 518172-1a.html 518172-a-ref.html
 fuzzy-if(winWidget,73,133) fuzzy-if(cocoaWidget,103,133) HTTP(..) == 518172-1b.html 518172-b-ref.html
@@ -1504,9 +1504,9 @@ fuzzy-if(!contentSameGfxBackendAsCanvas,128,91) random-if(d2d) skip-if(azureSkia
 fuzzy-if(skiaContent,4,5) == 557087-1.html 557087-ref.html
 fuzzy-if(skiaContent&&!Android,2,5) == 557087-2.html 557087-ref.html
 == 557736-1.html 557736-1-ref.html
-!= 558011-1.xul 558011-1-ref.xul
+fails-if(stylo||styloVsGecko) != 558011-1.xul 558011-1-ref.xul # bug 1408235
 == 559284-1.html 559284-1-ref.html
-fails-if(Android) == 560455-1.xul 560455-1-ref.xul
+fails-if(stylo||styloVsGecko||Android) == 560455-1.xul 560455-1-ref.xul # bug 1408235 for stylo
 fuzzy-if(skiaContent,2,5) == 561981-1.html 561981-1-ref.html
 == 561981-2.html 561981-2-ref.html
 fuzzy-if(skiaContent,1,5) == 561981-3.html 561981-3-ref.html
@@ -1688,12 +1688,12 @@ fuzzy-if(skiaContent,1,4500) == 654950-1.html 654950-1-ref.html # Quartz alpha b
 != 656875.html about:blank
 == 658952.html 658952-ref.html
 fuzzy-if(skiaContent,1,3500) == 660682-1.html 660682-1-ref.html
-fuzzy-if(d2d,1,256) skip-if(Android) fuzzy-if(skiaContent,1,68000) == 664127-1.xul 664127-1-ref.xul # Android: Intermittent failures - bug 1019131
+fuzzy-if(d2d,1,256) skip-if(Android) fuzzy-if(skiaContent,1,68000) fails-if(styloVsGecko) asserts-if(stylo,16-18) == 664127-1.xul 664127-1-ref.xul # Android: Intermittent failures - bug 1019131, stylo: bug 1397644
 == 665597-1.html 665597-1-ref.html
 == 665597-2.html 665597-2-ref.html
 == 667079-1.html 667079-1-ref.html
-== 668319-1.xul about:blank
-!= 669015-1.xul 669015-1-notref.xul
+fails-if(stylo||styloVsGecko) asserts-if(stylo,8-9) == 668319-1.xul about:blank # bug 1397644
+fails-if(stylo||styloVsGecko) != 669015-1.xul 669015-1-notref.xul # bug 1408235
 skip-if(azureSkiaGL) == 670442-1.html 670442-1-ref.html
 == 670467-1.html 670467-1-ref.html
 == 670467-2.html 670467-2-ref.html
diff --git a/layout/reftests/css-display/reftest.list b/layout/reftests/css-display/reftest.list
index e8acc6f50412..25feb9ac01fa 100644
--- a/layout/reftests/css-display/reftest.list
+++ b/layout/reftests/css-display/reftest.list
@@ -18,11 +18,11 @@ fuzzy-if(winWidget,12,100) skip-if(styloVsGecko||stylo) pref(layout.css.scoped-s
 == display-contents-495385-2d.html display-contents-495385-2d-ref.html
 fuzzy-if(Android,7,3935) == display-contents-xbl.xhtml display-contents-xbl-ref.html
 fuzzy-if(Android,7,1186) fails-if(stylo||styloVsGecko) pref(dom.webcomponents.enabled,true) pref(layout.css.scoped-style.enabled,true) == display-contents-shadow-dom-1.html display-contents-shadow-dom-1-ref.html
-== display-contents-xbl-2.xul display-contents-xbl-2-ref.xul
-== display-contents-xbl-3.xul display-contents-xbl-3-ref.xul
+fails-if(styloVsGecko) == display-contents-xbl-2.xul display-contents-xbl-2-ref.xul # bug 1408235
+fails-if(styloVsGecko) == display-contents-xbl-3.xul display-contents-xbl-3-ref.xul # bug 1408235
 skip == display-contents-xbl-4.xul display-contents-xbl-4-ref.xul # fails (not just asserts) due to bug 1089223
 asserts(0-1) fuzzy-if(Android,8,3216) == display-contents-fieldset.html display-contents-fieldset-ref.html # bug 1089223
-== display-contents-xbl-5.xul display-contents-xbl-3-ref.xul
+fails-if(styloVsGecko) == display-contents-xbl-5.xul display-contents-xbl-3-ref.xul # bug 1408235
 fails-if(!stylo) == display-contents-xbl-6.xhtml display-contents-xbl-6-ref.html # bug 1345809
 == display-contents-xbl-7.xhtml display-contents-xbl-7-ref.html
 == display-contents-list-item-child.html display-contents-list-item-child-ref.html
diff --git a/layout/reftests/forms/input/text/reftest.list b/layout/reftests/forms/input/text/reftest.list
index d900c1897139..b9aeedb9eb16 100644
--- a/layout/reftests/forms/input/text/reftest.list
+++ b/layout/reftests/forms/input/text/reftest.list
@@ -3,7 +3,7 @@ fuzzy-if(asyncPan&&!layersGPUAccelerated,151,111) == size-1.html size-1-ref.html
 == size-2.html size-2-ref.html
 HTTP(..) == baseline-1.html baseline-1-ref.html
 HTTP(..) == centering-1.xul centering-1-ref.xul
-== dynamic-height-1.xul dynamic-height-1-ref.xul
+fails-if(stylo) == dynamic-height-1.xul dynamic-height-1-ref.xul # bug 1408235
 fuzzy-if(skiaContent,1,500) needs-focus == select.html select-ref.html
 == intrinsic-size.html intrinsic-size-ref.html
 == line-height-0.5.html line-height-1.0.html
diff --git a/layout/reftests/forms/placeholder/reftest.list b/layout/reftests/forms/placeholder/reftest.list
index c5a77b443b32..946105cd1663 100644
--- a/layout/reftests/forms/placeholder/reftest.list
+++ b/layout/reftests/forms/placeholder/reftest.list
@@ -27,7 +27,7 @@ needs-focus == placeholder-10.html placeholder-visible-ref.html
 == placeholder-13.html placeholder-visible-ref.html
 == placeholder-14.html placeholder-visible-ref.html
 == placeholder-18.html placeholder-overridden-ref.html
-random-if(winWidget) == placeholder-19.xul  placeholder-overridden-ref.xul
+random-if(winWidget) fails-if(styloVsGecko) == placeholder-19.xul  placeholder-overridden-ref.xul # bug 1408811
 # needs-focus == placeholder-20.html placeholder-focus-ref.html
 needs-focus == placeholder-21.html placeholder-blank-ref.html
 needs-focus == placeholder-22.html placeholder-blank-ref.html
diff --git a/layout/reftests/forms/textbox/reftest.list b/layout/reftests/forms/textbox/reftest.list
index 18b92b72caee..a2d3b12c8610 100644
--- a/layout/reftests/forms/textbox/reftest.list
+++ b/layout/reftests/forms/textbox/reftest.list
@@ -1,11 +1,11 @@
 # access-key tests are no use on OS X because access keys are not indicated visually
 # no real XUL theme on Android so we just skip
-skip-if(cocoaWidget||Android) != accesskey-1.xul accesskey-1-notref.xul
-skip-if(cocoaWidget||Android) fails-if(webrender) == accesskey-2.xul accesskey-2-ref.xul
+skip-if(cocoaWidget||Android) fails-if(styloVsGecko) != accesskey-1.xul accesskey-1-notref.xul # stylo: bug 1408811
+skip-if(cocoaWidget||Android) fails-if(webrender) fails-if(stylo||styloVsGecko) == accesskey-2.xul accesskey-2-ref.xul # stylo: bug 1408811
 # accesskey-3 fails because of defects in XUL bidi support
-fails-if(!cocoaWidget) skip-if(cocoaWidget||Android) == accesskey-3.xul accesskey-3-ref.xul
-skip-if(cocoaWidget||Android) != accesskey-3.xul accesskey-3-notref.xul
-skip-if(cocoaWidget||Android) fails-if(webrender) == accesskey-4.xul accesskey-4-ref.xul
-skip-if(cocoaWidget||Android) != accesskey-4.xul accesskey-4-notref.xul
-skip-if(Android) == align-baseline-1.xul align-baseline-1-ref.xul # test for bug 494901
-skip-if(Android) == setsize.xul setsize-ref.xul
+fails-if(!cocoaWidget) skip-if(cocoaWidget||Android) fails-if(styloVsGecko) == accesskey-3.xul accesskey-3-ref.xul # stylo: bug 1408811
+skip-if(cocoaWidget||Android) fails-if(styloVsGecko) != accesskey-3.xul accesskey-3-notref.xul # stylo: bug 1408811
+skip-if(cocoaWidget||Android) fails-if(webrender) fails-if(stylo||styloVsGecko) == accesskey-4.xul accesskey-4-ref.xul # stylo: bug 1408811
+skip-if(cocoaWidget||Android) fails-if(styloVsGecko) != accesskey-4.xul accesskey-4-notref.xul # stylo: bug 1408811
+skip-if(Android) fails-if(styloVsGecko) == align-baseline-1.xul align-baseline-1-ref.xul # test for bug 494901, stylo: bug 1408811
+skip-if(Android) fails-if(stylo||styloVsGecko) == setsize.xul setsize-ref.xul # bug 1408235 for stylo
diff --git a/layout/reftests/invalidation/reftest.list b/layout/reftests/invalidation/reftest.list
index 08304516d173..ebf47e9cf235 100644
--- a/layout/reftests/invalidation/reftest.list
+++ b/layout/reftests/invalidation/reftest.list
@@ -4,7 +4,7 @@
 == table-repaint-c.html table-repaint-c-ref.html
 == table-repaint-d.html table-repaint-d-ref.html
 == table-repaint-non-border-collapse.html table-repaint-non-border-collapse-ref.html
-== 540247-1.xul 540247-1-ref.xul
+fails-if(styloVsGecko) == 540247-1.xul 540247-1-ref.xul # bug 1408235
 == 543681-1.html 543681-1-ref.html
 == 1243409-1.html 1243409-1-ref.html
 skip == test-image-layers.html test-image-layers-ref.html # Bug 1067360
diff --git a/layout/reftests/mathml/font-inflation-1-ref.html b/layout/reftests/mathml/font-inflation-1-ref.html
index d6c6fa5e3562..1f711b1918b8 100644
--- a/layout/reftests/mathml/font-inflation-1-ref.html
+++ b/layout/reftests/mathml/font-inflation-1-ref.html
@@ -28,21 +28,23 @@ should have the same size as inline math
       <mtext style="font-family: dtls-1" mathvariant="fraktur">a</mtext>
       <mo>+</mo>
     </mrow>
-  </math>, display math
-<math display="block">
-    <mrow id="display">
-      <mtext style="font-family: dtls-1" mathvariant="fraktur">a</mtext>
-      <mo>+</mo>
-    </mrow>
   </math>'
-or math in a table: <math><mtable><mtr>
+or math in a table: '<math><mtable><mtr>
     <mtd>
       <mrow id="cell">
         <mtext style="font-family: dtls-1" mathvariant="fraktur">a</mtext>
         <mo>+</mo>
       </mrow>
     </mtd>
-  </mtr></mtable></math>
+  </mtr></mtable></math>'
+(but not necessarily the same size as block-level math
+<math display="block">
+    <mrow id="display">
+      <mtext style="font-family: dtls-1" mathvariant="fraktur">a</mtext>
+      <mo>+</mo>
+    </mrow>
+  </math>
+because it forms a BFC and hence is its own inflation container.)
 Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
 tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
 quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
diff --git a/layout/reftests/mathml/font-inflation-1.html b/layout/reftests/mathml/font-inflation-1.html
index 1d24527fc444..45e25f21d577 100644
--- a/layout/reftests/mathml/font-inflation-1.html
+++ b/layout/reftests/mathml/font-inflation-1.html
@@ -14,7 +14,7 @@
     </style>
     <script type="text/javascript">
       function almostEqual(aX, aY) {
-        var epsilon = 2;
+        var epsilon = 2.6;
         return Math.abs(aX - aY) < epsilon;
       }
 
@@ -34,11 +34,9 @@
            against the reference mtext elements. */
         var ref = document.getElementById("ref");
         var inline = document.getElementById("inline");
-        var display = document.getElementById("display");
         var cell = document.getElementById("cell");
         for (var i = 0; i < ref.children.length; i++) {
           verifySize(inline.children[i], ref.children[i]);
-          verifySize(display.children[i], ref.children[i]);
           verifySize(cell.children[i], ref.children[i]);
         }
 
@@ -63,21 +61,23 @@ should have the same size as inline math
       <mtext style="font-family: dtls-1" mathvariant="fraktur">a</mtext>
       <mo>+</mo>
     </mrow>
-  </math>, display math
-<math display="block">
-    <mrow id="display">
-      <mtext style="font-family: dtls-1" mathvariant="fraktur">a</mtext>
-      <mo>+</mo>
-    </mrow>
   </math>'
-or math in a table: <math><mtable><mtr>
+or math in a table: '<math><mtable><mtr>
     <mtd>
       <mrow id="cell">
         <mtext style="font-family: dtls-1" mathvariant="fraktur">a</mtext>
         <mo>+</mo>
       </mrow>
     </mtd>
-  </mtr></mtable></math>
+  </mtr></mtable></math>'
+(but not necessarily the same size as block-level math
+<math display="block">
+    <mrow id="display">
+      <mtext style="font-family: dtls-1" mathvariant="fraktur">a</mtext>
+      <mo>+</mo>
+    </mrow>
+  </math>
+because it forms a BFC and hence is its own inflation container.)
 Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
 tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
 quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
diff --git a/layout/reftests/native-theme/reftest.list b/layout/reftests/native-theme/reftest.list
index 590327fc4636..99bc43746903 100644
--- a/layout/reftests/native-theme/reftest.list
+++ b/layout/reftests/native-theme/reftest.list
@@ -30,11 +30,11 @@ fails-if(!nativeThemePref) != checkbox-native.html checkbox-nonnative.html
 != 427122-1.html 427122-1-ref.html
 
 # 403458 is a Windows-only bug
-skip-if(!winWidget) != 403458-winmenu-ltr.xul 403458-winmenu-rtl.xul
+fails-if(stylo) skip-if(!winWidget) != 403458-winmenu-ltr.xul 403458-winmenu-rtl.xul # stylo: bug 1408235
 
-== 470711-1.xul 470711-1-ref.xul
+fails-if(stylo||styloVsGecko) == 470711-1.xul 470711-1-ref.xul # bug 1408235
 
-== 482955-1.xul 482955-1-ref.xul
+fails-if(styloVsGecko) == 482955-1.xul 482955-1-ref.xul # bug 1408235
 
 == 492155-1.html about:blank
 == 492155-2.html about:blank
@@ -54,16 +54,16 @@ skip-if(!cocoaWidget) == select-mirrored-when-rtl.html select-mirrored-when-rtl-
 
 != resizer-bottomend.xul blank-window.xul
 random-if(d2d) == resizer-bottomend.xul resizer-bottomright.xul # bug 581086 
-!= resizer-bottomend.xul resizer-bottomend-rtl.xul
+fails-if(stylo) != resizer-bottomend.xul resizer-bottomend-rtl.xul # bug 1408235
 skip-if(gtkWidget) != resizer-bottomend-rtl.xul blank-window.xul
 skip-if(gtkWidget) random-if(d2d) == resizer-bottomend-rtl.xul resizer-bottomend-flipped.xul # bug 581086
 
 != resizer-bottomstart.xul blank-window.xul
 random-if(d2d) == resizer-bottomstart.xul resizer-bottomleft.xul
 random-if(d2d) == resizer-bottomstart.xul resizer-left.xul
-!= resizer-bottomstart.xul resizer-bottomstart-rtl.xul
+fails-if(stylo) != resizer-bottomstart.xul resizer-bottomstart-rtl.xul # bug 1408235
 skip-if(gtkWidget) != resizer-bottomstart-rtl.xul blank-window.xul
-skip-if(gtkWidget) random-if(d2d) == resizer-bottomstart-rtl.xul resizer-bottomend.xul
+fails-if(stylo) skip-if(gtkWidget) random-if(d2d) == resizer-bottomstart-rtl.xul resizer-bottomend.xul # bug 1408235
 
 # Windows-only, depends on native scrollbar metrics
 skip-if(!winWidget) == scroll-thumb-minimum-size-notheme.html scroll-thumb-minimum-size-notheme-ref.html
@@ -81,4 +81,4 @@ skip-if(!winWidget) == scroll-thumb-minimum-size-notheme.html scroll-thumb-minim
 skip-if(cocoaWidget) skip-if(winWidget) == progress-overflow.html progress-overflow-ref.html
 fails-if(Android) skip-if(cocoaWidget) skip-if(winWidget) != progress-overflow-small.html progress-nobar.html
 
-== 676387-1.xul 676387-1-ref.xul
+fails-if(styloVsGecko) == 676387-1.xul 676387-1-ref.xul # bug 1408824
diff --git a/layout/reftests/reftest-sanity/reftest.list b/layout/reftests/reftest-sanity/reftest.list
index 01056607f619..ce2b531ff7d3 100644
--- a/layout/reftests/reftest-sanity/reftest.list
+++ b/layout/reftests/reftest-sanity/reftest.list
@@ -3,7 +3,7 @@
 != data:text/plain,HELLO about:blank
 
 # these tests make sure async reftests work:
-== test-async.xul test-async-ref.xul
+fails-if(styloVsGecko) == test-async.xul test-async-ref.xul # bug 1408235
 == test-async.html test-async-ref.html
 
 # test that zoom works (and really zooms, not just scales)
diff --git a/layout/reftests/reftest.list b/layout/reftests/reftest.list
index 560f24e0fd57..c273cc39e328 100644
--- a/layout/reftests/reftest.list
+++ b/layout/reftests/reftest.list
@@ -402,7 +402,10 @@ include ../../widget/reftests/reftest.list
 include ../../dom/tests/reftest/xml-stylesheet/reftest.list
 
 # xul-document-load/ (no XUL theme on Android)
-skip-if(Android) include xul-document-load/reftest.list
+# skip for stylo because the reference page is wrong due to bug 1408235.
+# There are some pages rendered incorrectly in the same way, so this
+# test set is basically broken and not worth further annotating.
+skip-if(Android||stylo||styloVsGecko) include xul-document-load/reftest.list
 
 # xul/ (no XUL theme on Android)
 skip-if(Android) include xul/reftest.list
diff --git a/layout/reftests/text-shadow/reftest.list b/layout/reftests/text-shadow/reftest.list
index 95b8ec10fc71..0c8e60c1442b 100644
--- a/layout/reftests/text-shadow/reftest.list
+++ b/layout/reftests/text-shadow/reftest.list
@@ -1,10 +1,10 @@
 == 723669.html 723669-ref.html
 
-== basic.xul basic-ref.xul
-random-if(Android) == basic-negcoord.xul basic-negcoord-ref.xul
-!= blur.xul blur-notref.xul
-== color-inherit.xul color-inherit-ref.xul
-== multiple-noblur.xul multiple-noblur-ref.xul
+fails-if(stylo||styloVsGecko) == basic.xul basic-ref.xul # bug 1408235
+fails-if(stylo||styloVsGecko) random-if(Android) == basic-negcoord.xul basic-negcoord-ref.xul # bug 1408235
+fails-if(stylo||styloVsGecko) != blur.xul blur-notref.xul # bug 1408235
+fails-if(stylo||styloVsGecko) == color-inherit.xul color-inherit-ref.xul # bug 1408235
+fails-if(stylo||styloVsGecko) == multiple-noblur.xul multiple-noblur-ref.xul # bug 1408235
 HTTP(..) == blur-opacity.html blur-opacity-ref.html
 
 == basic.html basic-ref.html
diff --git a/layout/reftests/transform-3d/reftest.list b/layout/reftests/transform-3d/reftest.list
index 396ef166c58c..fa5f282f7d01 100644
--- a/layout/reftests/transform-3d/reftest.list
+++ b/layout/reftests/transform-3d/reftest.list
@@ -54,7 +54,7 @@ fuzzy-if(winWidget&&!layersGPUAccelerated,1,61) == perspective-origin-3a.html pe
 == sorting-2b.html sorting-2-ref.html
 == sorting-3a.html green-rect.html
 # Different, but equivalent (for the given transform) transform origins
-fuzzy-if(webrender,0-1,0-2) == rotatex-transformorigin-1a.html rotatex-transformorigin-1-ref.html
+fuzzy-if(webrender,0-1,0-4) == rotatex-transformorigin-1a.html rotatex-transformorigin-1-ref.html
 fuzzy-if((gtkWidget&&layersOMTC)||(winWidget&&!layersGPUAccelerated),1,86) == overflow-hidden-1a.html overflow-hidden-1-ref.html
 fails-if(webrender) == transform-style-flat-1a.html transform-style-flat-1-ref.html
 == willchange-containing-block.html?willchange willchange-containing-block.html?ref
diff --git a/layout/reftests/xul/reftest.list b/layout/reftests/xul/reftest.list
index 2fcf7752aa59..c622428726e0 100644
--- a/layout/reftests/xul/reftest.list
+++ b/layout/reftests/xul/reftest.list
@@ -1,17 +1,17 @@
 == css-flex-1.xul css-flex-1-ref.html
 
-== menuitem-key.xul menuitem-key-ref.xul
+fails-if(styloVsGecko) == menuitem-key.xul menuitem-key-ref.xul # bug 1408831
 # these random-if(Android) are due to differences between Android Native & Xul, see bug 732569
-random-if(Android) == menulist-shrinkwrap-1.xul menulist-shrinkwrap-1-ref.xul
-random-if(Android) fails-if(winWidget) == menulist-shrinkwrap-2.xul menulist-shrinkwrap-2-ref.xul
-== textbox-overflow-1.xul textbox-overflow-1-ref.xul # for bug 749658
+random-if(Android) fails-if(stylo||styloVsGecko) == menulist-shrinkwrap-1.xul menulist-shrinkwrap-1-ref.xul # stylo: bug 1408235
+random-if(Android) fails-if(winWidget||stylo||styloVsGecko) == menulist-shrinkwrap-2.xul menulist-shrinkwrap-2-ref.xul # stylo: bug 1408235
+fails-if(styloVsGecko) == textbox-overflow-1.xul textbox-overflow-1-ref.xul # for bug 749658, stylo: bug 1408235
 # accesskeys are not normally displayed on Mac, so skip this test
-skip-if(cocoaWidget) == accesskey.xul accesskey-ref.xul
-fails-if(cocoaWidget) fuzzy-if(xulRuntime.widgetToolkit=="gtk3",1,11) == tree-row-outline-1.xul tree-row-outline-1-ref.xul # win8: bug 1254832
+skip-if(cocoaWidget) fails-if(styloVsGecko) == accesskey.xul accesskey-ref.xul # stylo: bug 1408811
+fails-if(cocoaWidget&&!stylo) fuzzy-if(xulRuntime.widgetToolkit=="gtk3",1,11) asserts-if(stylo,13-26) fails-if(styloVsGecko) == tree-row-outline-1.xul tree-row-outline-1-ref.xul # win8: bug 1254832, stylo: bug 1397644
 skip-if(!cocoaWidget) == mac-tab-toolbar.xul mac-tab-toolbar-ref.xul
-!= tree-row-outline-1.xul tree-row-outline-1-notref.xul
+asserts-if(stylo,13-26) fails-if(stylo||styloVsGecko) != tree-row-outline-1.xul tree-row-outline-1-notref.xul # stylo: bug 1397644
 == text-crop.xul text-crop-ref.xul
-== text-small-caps-1.xul text-small-caps-1-ref.xul
+fails-if(stylo||styloVsGecko) == text-small-caps-1.xul text-small-caps-1-ref.xul # stylo: bug 1408235
 fuzzy-if(skiaContent,1,60) fuzzy-if(cocoaWidget&&browserIsRemote&&!skiaContent,1,31) fuzzy-if(winWidget&&browserIsRemote&&layersGPUAccelerated,1,50) == inactive-fixed-bg-bug1205630.xul inactive-fixed-bg-bug1205630-ref.html
 fuzzy-if(skiaContent,1,60) fuzzy-if(cocoaWidget&&browserIsRemote&&!skiaContent,1,31) fuzzy-if(winWidget&&browserIsRemote&&layersGPUAccelerated,1,50) == inactive-fixed-bg-bug1272525.xul inactive-fixed-bg-bug1272525-ref.html
 
@@ -62,8 +62,8 @@ fails == object-fit-fill-svg-006.xul object-fit-fill-svg-006-ref.html # bug 1092
 == object-position-png-001.xul object-position-png-001-ref.html
 == object-position-png-002.xul object-position-png-002-ref.html
 
-== stack-sizing-1.xul stack-sizing-1-ref.xul
-== stack-sizing-2.xul stack-sizing-2-ref.xul
+fails-if(styloVsGecko) == stack-sizing-1.xul stack-sizing-1-ref.xul # bug 1408235
+fails-if(styloVsGecko) == stack-sizing-2.xul stack-sizing-2-ref.xul # bug 1408235
 
 # Tests for rendering SVG images in a XUL <treecell>:
 # XXXdholbert: These are marked as "random" right now, since they might not
@@ -72,4 +72,4 @@ fails == object-fit-fill-svg-006.xul object-fit-fill-svg-006-ref.html # bug 1092
 skip == treecell-image-svg-1a.xul treecell-image-svg-1-ref.xul # bug 1218954
 skip == treecell-image-svg-1b.xul treecell-image-svg-1-ref.xul # bug 1218954
 
-== treechildren-padding-percent-1.xul treechildren-padding-percent-1-ref.xul
+asserts-if(stylo,16-18) fails-if(styloVsGecko) == treechildren-padding-percent-1.xul treechildren-padding-percent-1-ref.xul # bug 1397644
diff --git a/layout/style/ServoBindingList.h b/layout/style/ServoBindingList.h
index 0b90c02850c2..779590860bfd 100644
--- a/layout/style/ServoBindingList.h
+++ b/layout/style/ServoBindingList.h
@@ -682,6 +682,14 @@ SERVO_BINDING_FUNC(Servo_ReleaseArcStringData, void,
 SERVO_BINDING_FUNC(Servo_CloneArcStringData, mozilla::ServoRawOffsetArc<RustString>,
                    const mozilla::ServoRawOffsetArc<RustString>* string);
 
+// CSS parsing utility functions.
+SERVO_BINDING_FUNC(Servo_IsValidCSSColor, bool, const nsAString* value);
+SERVO_BINDING_FUNC(Servo_ComputeColor, bool,
+                   RawServoStyleSetBorrowedOrNull set,
+                   nscolor current_color,
+                   const nsAString* value,
+                   nscolor* result_color);
+
 // AddRef / Release functions
 #define SERVO_ARC_TYPE(name_, type_)                                \
   SERVO_BINDING_FUNC(Servo_##name_##_AddRef, void, type_##Borrowed) \
diff --git a/layout/style/ServoCSSParser.cpp b/layout/style/ServoCSSParser.cpp
new file mode 100644
index 000000000000..abbb96968aab
--- /dev/null
+++ b/layout/style/ServoCSSParser.cpp
@@ -0,0 +1,27 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* CSS parsing utility functions */
+
+#include "ServoCSSParser.h"
+
+using namespace mozilla;
+
+/* static */ bool
+ServoCSSParser::IsValidCSSColor(const nsAString& aValue)
+{
+  return Servo_IsValidCSSColor(&aValue);
+}
+
+/* static */ bool
+ServoCSSParser::ComputeColor(ServoStyleSet* aStyleSet,
+                             nscolor aCurrentColor,
+                             const nsAString& aValue,
+                             nscolor* aResultColor)
+{
+  return Servo_ComputeColor(aStyleSet ? aStyleSet->RawSet() : nullptr,
+                            aCurrentColor, &aValue, aResultColor);
+}
diff --git a/layout/style/ServoCSSParser.h b/layout/style/ServoCSSParser.h
new file mode 100644
index 000000000000..ff4e271f6c78
--- /dev/null
+++ b/layout/style/ServoCSSParser.h
@@ -0,0 +1,45 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* CSS parsing utility functions */
+
+#ifndef mozilla_ServoCSSParser_h
+#define mozilla_ServoCSSParser_h
+
+#include "mozilla/ServoBindings.h"
+
+namespace mozilla {
+
+class ServoCSSParser
+{
+public:
+  /**
+   * Returns whether the specified string can be parsed as a valid CSS
+   * <color> value.
+   *
+   * This includes Mozilla-specific keywords such as -moz-default-color.
+   */
+  static bool IsValidCSSColor(const nsAString& aValue);
+
+  /**
+   * Computes an nscolor from the given CSS <color> value.
+   *
+   * @param aStyleSet The style set whose nsPresContext will be used to
+   *   compute system colors and other special color values.
+   * @param aCurrentColor The color value that currentcolor should compute to.
+   * @param aValue The CSS <color> value.
+   * @param aResultColor The resulting computed color value.
+   * @return Whether aValue was successfully parsed and aResultColor was set.
+   */
+  static bool ComputeColor(ServoStyleSet* aStyleSet,
+                           nscolor aCurrentColor,
+                           const nsAString& aValue,
+                           nscolor* aResultColor);
+};
+
+} // namespace mozilla
+
+#endif // mozilla_ServoCSSParser_h
diff --git a/layout/style/moz.build b/layout/style/moz.build
index 0758a93e00bd..10529f067d1f 100644
--- a/layout/style/moz.build
+++ b/layout/style/moz.build
@@ -103,6 +103,7 @@ EXPORTS.mozilla += [
     'ServoBindingList.h',
     'ServoBindings.h',
     'ServoBindingTypes.h',
+    'ServoCSSParser.h',
     'ServoCSSRuleList.h',
     'ServoDeclarationBlock.h',
     'ServoDocumentRule.h',
@@ -249,6 +250,7 @@ UNIFIED_SOURCES += [
     'RuleNodeCacheConditions.cpp',
     'RuleProcessorCache.cpp',
     'ServoBindings.cpp',
+    'ServoCSSParser.cpp',
     'ServoCSSRuleList.cpp',
     'ServoDeclarationBlock.cpp',
     'ServoDocumentRule.cpp',
diff --git a/layout/style/nsCSSRuleProcessor.cpp b/layout/style/nsCSSRuleProcessor.cpp
index cb2ba1ee65d9..e7a6e4fa6112 100644
--- a/layout/style/nsCSSRuleProcessor.cpp
+++ b/layout/style/nsCSSRuleProcessor.cpp
@@ -1159,12 +1159,6 @@ nsCSSRuleProcessor::InitSystemMetrics()
     sSystemMetrics->AppendElement(nsGkAtoms::swipe_animation_enabled);
   }
 
-  rv = LookAndFeel::GetInt(LookAndFeel::eIntID_PhysicalHomeButton,
-                           &metricResult);
-  if (NS_SUCCEEDED(rv) && metricResult) {
-    sSystemMetrics->AppendElement(nsGkAtoms::physical_home_button);
-  }
-
 #ifdef XP_WIN
   if (NS_SUCCEEDED(
         LookAndFeel::GetInt(LookAndFeel::eIntID_WindowsThemeIdentifier,
diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp
index dd1a9f3413be..1067f509e466 100644
--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -3616,7 +3616,7 @@ nsComputedDOMStyle::GetScrollSnapPoints(const nsStyleCoord& aCoord)
     val->SetIdent(eCSSKeyword_none);
   } else {
     nsAutoString argumentString;
-    SetCssTextToCoord(argumentString, aCoord);
+    SetCssTextToCoord(argumentString, aCoord, true);
     nsAutoString tmp;
     tmp.AppendLiteral("repeat(");
     tmp.Append(argumentString);
@@ -6306,14 +6306,15 @@ nsComputedDOMStyle::DoGetStopColor()
 
 void
 nsComputedDOMStyle::BoxValuesToString(nsAString& aString,
-                                      const nsTArray<nsStyleCoord>& aBoxValues)
+                                      const nsTArray<nsStyleCoord>& aBoxValues,
+                                      bool aClampNegativeCalc)
 {
   MOZ_ASSERT(aBoxValues.Length() == 4, "wrong number of box values");
   nsAutoString value1, value2, value3, value4;
-  SetCssTextToCoord(value1, aBoxValues[0]);
-  SetCssTextToCoord(value2, aBoxValues[1]);
-  SetCssTextToCoord(value3, aBoxValues[2]);
-  SetCssTextToCoord(value4, aBoxValues[3]);
+  SetCssTextToCoord(value1, aBoxValues[0], aClampNegativeCalc);
+  SetCssTextToCoord(value2, aBoxValues[1], aClampNegativeCalc);
+  SetCssTextToCoord(value3, aBoxValues[2], aClampNegativeCalc);
+  SetCssTextToCoord(value4, aBoxValues[3], aClampNegativeCalc);
 
   // nsROCSSPrimitiveValue do not have binary comparison operators.
   // Compare string results instead.
@@ -6344,8 +6345,8 @@ nsComputedDOMStyle::BasicShapeRadiiToString(nsAString& aCssText,
     vertical.AppendElement(
       aCorners.Get(FullToHalfCorner(corner, true)));
   }
-  BoxValuesToString(horizontalString, horizontal);
-  BoxValuesToString(verticalString, vertical);
+  BoxValuesToString(horizontalString, horizontal, true);
+  BoxValuesToString(verticalString, vertical, true);
   aCssText.Append(horizontalString);
   if (horizontalString == verticalString) {
     return;
@@ -6381,11 +6382,13 @@ nsComputedDOMStyle::CreatePrimitiveValueForBasicShape(
           shapeFunctionString.AppendLiteral(", ");
         }
         SetCssTextToCoord(coordString,
-                          aStyleBasicShape->Coordinates()[i]);
+                          aStyleBasicShape->Coordinates()[i],
+                          false);
         shapeFunctionString.Append(coordString);
         shapeFunctionString.Append(' ');
         SetCssTextToCoord(coordString,
-                          aStyleBasicShape->Coordinates()[i + 1]);
+                          aStyleBasicShape->Coordinates()[i + 1],
+                          false);
         shapeFunctionString.Append(coordString);
       }
       break;
@@ -6416,7 +6419,7 @@ nsComputedDOMStyle::CreatePrimitiveValueForBasicShape(
       break;
     }
     case StyleBasicShapeType::Inset: {
-      BoxValuesToString(shapeFunctionString, aStyleBasicShape->Coordinates());
+      BoxValuesToString(shapeFunctionString, aStyleBasicShape->Coordinates(), false);
       if (aStyleBasicShape->HasRadius()) {
         shapeFunctionString.AppendLiteral(" round ");
         nsAutoString radiiString;
@@ -6504,11 +6507,11 @@ nsComputedDOMStyle::DoGetShapeOutside()
 
 void
 nsComputedDOMStyle::SetCssTextToCoord(nsAString& aCssText,
-                                      const nsStyleCoord& aCoord)
+                                      const nsStyleCoord& aCoord,
+                                      bool aClampNegativeCalc)
 {
   RefPtr<nsROCSSPrimitiveValue> value = new nsROCSSPrimitiveValue;
-  bool clampNegativeCalc = true;
-  SetValueToCoord(value, aCoord, clampNegativeCalc);
+  SetValueToCoord(value, aCoord, aClampNegativeCalc);
   value->GetCssText(aCssText);
 }
 
@@ -6544,7 +6547,7 @@ nsComputedDOMStyle::CreatePrimitiveValueForStyleFilter(
     shadowValue->GetCssText(argumentString, dummy);
   } else {
     // Filter function argument.
-    SetCssTextToCoord(argumentString, aStyleFilter.GetFilterParameter());
+    SetCssTextToCoord(argumentString, aStyleFilter.GetFilterParameter(), true);
   }
   filterFunctionString.Append(argumentString);
 
diff --git a/layout/style/nsComputedDOMStyle.h b/layout/style/nsComputedDOMStyle.h
index 70f07afffe52..858a40519f2d 100644
--- a/layout/style/nsComputedDOMStyle.h
+++ b/layout/style/nsComputedDOMStyle.h
@@ -692,8 +692,9 @@ private:
   bool GetFrameBorderRectWidth(nscoord& aWidth);
   bool GetFrameBorderRectHeight(nscoord& aHeight);
 
-  /* Helper functions for computing the filter property style. */
-  void SetCssTextToCoord(nsAString& aCssText, const nsStyleCoord& aCoord);
+  /* Helper functions for computing and serializing a nsStyleCoord. */
+  void SetCssTextToCoord(nsAString& aCssText, const nsStyleCoord& aCoord,
+                         bool aClampNegativeCalc);
   already_AddRefed<CSSValue> CreatePrimitiveValueForStyleFilter(
     const nsStyleFilter& aStyleFilter);
 
@@ -712,7 +713,8 @@ private:
   already_AddRefed<CSSValue> CreatePrimitiveValueForBasicShape(
     const mozilla::UniquePtr<mozilla::StyleBasicShape>& aStyleBasicShape);
   void BoxValuesToString(nsAString& aString,
-                         const nsTArray<nsStyleCoord>& aBoxValues);
+                         const nsTArray<nsStyleCoord>& aBoxValues,
+                         bool aClampNegativeCalc);
   void BasicShapeRadiiToString(nsAString& aCssText,
                                const nsStyleCorners& aCorners);
 
diff --git a/layout/style/nsMediaFeatures.cpp b/layout/style/nsMediaFeatures.cpp
index c53f81b95779..1c8c8d26fba6 100644
--- a/layout/style/nsMediaFeatures.cpp
+++ b/layout/style/nsMediaFeatures.cpp
@@ -637,7 +637,7 @@ nsMediaFeatures::features[] = {
     &nsGkAtoms::_moz_scrollbar_start_backward,
     nsMediaFeature::eMinMaxNotAllowed,
     nsMediaFeature::eBoolInteger,
-    nsMediaFeature::eNoRequirements,
+    nsMediaFeature::eUserAgentAndChromeOnly,
     { &nsGkAtoms::scrollbar_start_backward },
     GetSystemMetric
   },
@@ -645,7 +645,7 @@ nsMediaFeatures::features[] = {
     &nsGkAtoms::_moz_scrollbar_start_forward,
     nsMediaFeature::eMinMaxNotAllowed,
     nsMediaFeature::eBoolInteger,
-    nsMediaFeature::eNoRequirements,
+    nsMediaFeature::eUserAgentAndChromeOnly,
     { &nsGkAtoms::scrollbar_start_forward },
     GetSystemMetric
   },
@@ -653,7 +653,7 @@ nsMediaFeatures::features[] = {
     &nsGkAtoms::_moz_scrollbar_end_backward,
     nsMediaFeature::eMinMaxNotAllowed,
     nsMediaFeature::eBoolInteger,
-    nsMediaFeature::eNoRequirements,
+    nsMediaFeature::eUserAgentAndChromeOnly,
     { &nsGkAtoms::scrollbar_end_backward },
     GetSystemMetric
   },
@@ -661,7 +661,7 @@ nsMediaFeatures::features[] = {
     &nsGkAtoms::_moz_scrollbar_end_forward,
     nsMediaFeature::eMinMaxNotAllowed,
     nsMediaFeature::eBoolInteger,
-    nsMediaFeature::eNoRequirements,
+    nsMediaFeature::eUserAgentAndChromeOnly,
     { &nsGkAtoms::scrollbar_end_forward },
     GetSystemMetric
   },
@@ -669,7 +669,7 @@ nsMediaFeatures::features[] = {
     &nsGkAtoms::_moz_scrollbar_thumb_proportional,
     nsMediaFeature::eMinMaxNotAllowed,
     nsMediaFeature::eBoolInteger,
-    nsMediaFeature::eNoRequirements,
+    nsMediaFeature::eUserAgentAndChromeOnly,
     { &nsGkAtoms::scrollbar_thumb_proportional },
     GetSystemMetric
   },
@@ -779,15 +779,6 @@ nsMediaFeatures::features[] = {
     GetSystemMetric
   },
 
-  {
-    &nsGkAtoms::_moz_physical_home_button,
-    nsMediaFeature::eMinMaxNotAllowed,
-    nsMediaFeature::eBoolInteger,
-    nsMediaFeature::eNoRequirements,
-    { &nsGkAtoms::physical_home_button },
-    GetSystemMetric
-  },
-
   // Internal -moz-is-glyph media feature: applies only inside SVG glyphs.
   // Internal because it is really only useful in the user agent anyway
   //  and therefore not worth standardizing.
diff --git a/layout/style/test/chrome/bug418986-2.js b/layout/style/test/chrome/bug418986-2.js
index 50d9a48a26f5..0680d328db97 100644
--- a/layout/style/test/chrome/bug418986-2.js
+++ b/layout/style/test/chrome/bug418986-2.js
@@ -51,6 +51,14 @@ var suppressed_toggles = [
   "-moz-windows-glass",
 ];
 
+var toggles_enabled_in_content = [
+  "-moz-mac-graphite-theme",
+  "-moz-touch-enabled",
+  "-moz-windows-compositor",
+  "-moz-windows-default-theme",
+  "-moz-windows-glass",
+];
+
 // Possible values for '-moz-os-version'
 var windows_versions = [
   "windows-win7",
@@ -77,6 +85,7 @@ var OS = SpecialPowers.Services.appinfo.OS;
 // available on that OS.
 if (OS === "WINNT") {
   suppressed_toggles.push("-moz-windows-classic");
+  toggles_enabled_in_content.push("-moz-windows-classic");
 }
 
 // __keyValMatches(key, val)__.
@@ -104,7 +113,7 @@ var testToggles = function (resisting) {
   suppressed_toggles.forEach(
     function (key) {
       var exists = keyValMatches(key, 0) || keyValMatches(key, 1);
-      if (resisting) {
+      if (resisting || toggles_enabled_in_content.indexOf(key) === -1) {
          ok(!exists, key + " should not exist.");
       } else {
          ok(exists, key + " should exist.");
@@ -193,6 +202,7 @@ var suppressedMediaQueryCSSLine = function (key, color, suppressed) {
 // expected value, then the element will be colored green.
 var generateCSSLines = function (resisting) {
   let lines = ".spoof { background-color: red;}\n";
+  let is_chrome_window = window.location.protocol === "chrome:";
   expected_values.forEach(
     function ([key, offVal, onVal]) {
       lines += mediaQueryCSSLine(key, resisting ? onVal : offVal, "green");
@@ -200,7 +210,11 @@ var generateCSSLines = function (resisting) {
   lines += ".suppress { background-color: " + (resisting ? "green" : "red") + ";}\n";
   suppressed_toggles.forEach(
     function (key) {
-      lines += suppressedMediaQueryCSSLine(key, resisting ? "red" : "green");
+      if (toggles_enabled_in_content.indexOf(key) === -1 && !resisting && !is_chrome_window) {
+        lines += "#" + key + " { background-color: green; }\n";
+      } else {
+        lines += suppressedMediaQueryCSSLine(key, resisting ? "red" : "green");
+      }
     });
   if (OS === "WINNT") {
     lines += ".windows { background-color: " + (resisting ? "green" : "red") + ";}\n";
diff --git a/layout/style/test/test_bug1112014.html b/layout/style/test/test_bug1112014.html
index 377494e9785a..b17cdc6317a8 100644
--- a/layout/style/test/test_bug1112014.html
+++ b/layout/style/test/test_bug1112014.html
@@ -20,7 +20,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1112014
     TYPE_LENGTH: "10px",
     TYPE_PERCENTAGE: "50%",
     TYPE_COLOR: "rgb(3,3,3)",
-    TYPE_URL: "url(mozilla.org)",
+    TYPE_URL: "url(http://example.org/)",
     TYPE_ANGLE: "90deg",
     TYPE_FREQUENCY: "10kHz",
     TYPE_TIME: "1000ms",
@@ -74,6 +74,12 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1112014
       TYPE_LENGTH: "'something' 23px",
       TYPE_PERCENTAGE: "'something' 23%"
     },
+    "cursor": {
+      TYPE_URL: testValues.TYPE_URL + ", pointer"
+    },
+    "-moz-force-broken-image-icon": {
+      TYPE_NUMBER: "1"
+    }
   };
 
 
@@ -102,7 +108,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1112014
 
       let supported =
         utils.cssPropertySupportsType(propertyName, utils[iter]);
-      let parsed = utils.cssPropertyIsValid(propertyName, testValue);
+      let parsed = CSS.supports(propertyName, testValue);
       is(supported, parsed, propertyName + " supports " + iter);
     }
   }
diff --git a/layout/style/test/test_computed_style.html b/layout/style/test/test_computed_style.html
index 177133843e53..b1d37df75ce0 100644
--- a/layout/style/test/test_computed_style.html
+++ b/layout/style/test/test_computed_style.html
@@ -702,6 +702,36 @@ var noframe_container = document.getElementById("content");
   p.remove();
 })();
 
+(function test_bug_1378368() {
+  // Test that negative results of calc()s in basic-shapes (e.g. polygon()) should
+  // not be clamped to 0px.
+  var clipPaths = [
+    // [ specified style,
+    //   expected computed style,
+    //   descriptionOfTestcase ],
+    // polygon:
+    [ "polygon(calc(10px - 20px) 0px, 100px 100px, 0px 100px)",
+      "polygon(-10px 0px, 100px 100px, 0px 100px)",
+      "polygon with negative calc() coordinates" ],
+    // inset:
+    [ "inset(calc(10px - 20px))",
+      "inset(-10px)",
+      "inset with negative calc() coordinates" ],
+  ];
+
+  var p = document.createElement("p");
+  var cs = getComputedStyle(p, "");
+  frame_container.appendChild(p);
+
+  for (let test of clipPaths) {
+    p.style.clipPath = test[0];
+    is(cs.clipPath, test[1],
+       "computed value of clip-path for basic-shapes (" + test[2] + ")");
+  }
+
+  p.remove();
+})();
+
 </script>
 </pre>
 </body>
diff --git a/layout/style/test/test_hover_quirk.html b/layout/style/test/test_hover_quirk.html
index ee8d9f633e13..5f1042691df4 100644
--- a/layout/style/test/test_hover_quirk.html
+++ b/layout/style/test/test_hover_quirk.html
@@ -38,6 +38,22 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=783213
     #content :hover .child::after {
       content: "link child" !important;
     }
+
+    #dynamic-test {
+      width: 100px;
+      height: 100px;
+      background: green;
+    }
+
+    #dynamic-test > * {
+      width: 100%;
+      height: 100%;
+      background: red;
+    }
+
+    #dynamic-test:hover > * {
+      background: rgb(0, 255, 0);
+    }
   </style>
   <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
   <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
@@ -75,6 +91,12 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=783213
       test(document.getElementById("label"), false);
       test(document.getElementById("link"), true);
       test(document.getElementById("div"), false);
+      // Dynamic change test.
+      // Trigger the :hover pseudo-class.
+      synthesizeMouseAtCenter(document.getElementById('dynamic-test'), {type: "mousemove"});
+      is(getComputedStyle(document.getElementById('should-be-green-on-hover')).backgroundColor,
+         "rgb(0, 255, 0)",
+         "Dynamic change should invalidate properly");
       SimpleTest.finish();
     });
   </script>
@@ -82,6 +104,9 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=783213
 <body>
   <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=783213">Mozilla Bug 783213</a>
   <p id="display"></p>
+  <div id="dynamic-test">
+    <div id="should-be-green-on-hover"></div>
+  </div>
   <div id="content">
     <span id="span">Span<span class="child"></span></span><br>
     <label id="label">Label<span class="child"></span></label><br>
diff --git a/layout/style/test/test_media_queries.html b/layout/style/test/test_media_queries.html
index b9e7058ef2c2..55d889ebc53b 100644
--- a/layout/style/test/test_media_queries.html
+++ b/layout/style/test/test_media_queries.html
@@ -633,11 +633,11 @@ function run() {
   should_not_apply("(grid: -1)");
 
   // System metrics
-  expression_should_be_parseable("-moz-scrollbar-start-backward");
-  expression_should_be_parseable("-moz-scrollbar-start-forward");
-  expression_should_be_parseable("-moz-scrollbar-end-backward");
-  expression_should_be_parseable("-moz-scrollbar-end-forward");
-  expression_should_be_parseable("-moz-scrollbar-thumb-proportional");
+  expression_should_not_be_parseable("-moz-scrollbar-start-backward");
+  expression_should_not_be_parseable("-moz-scrollbar-start-forward");
+  expression_should_not_be_parseable("-moz-scrollbar-end-backward");
+  expression_should_not_be_parseable("-moz-scrollbar-end-forward");
+  expression_should_not_be_parseable("-moz-scrollbar-thumb-proportional");
   expression_should_be_parseable("-moz-overlay-scrollbars");
   expression_should_be_parseable("-moz-windows-default-theme");
   expression_should_be_parseable("-moz-mac-graphite-theme");
@@ -649,11 +649,11 @@ function run() {
   expression_should_be_parseable("-moz-touch-enabled");
   expression_should_be_parseable("-moz-swipe-animation-enabled");
 
-  expression_should_be_parseable("-moz-scrollbar-start-backward: 0");
-  expression_should_be_parseable("-moz-scrollbar-start-forward: 0");
-  expression_should_be_parseable("-moz-scrollbar-end-backward: 0");
-  expression_should_be_parseable("-moz-scrollbar-end-forward: 0");
-  expression_should_be_parseable("-moz-scrollbar-thumb-proportional: 0");
+  expression_should_not_be_parseable("-moz-scrollbar-start-backward: 0");
+  expression_should_not_be_parseable("-moz-scrollbar-start-forward: 0");
+  expression_should_not_be_parseable("-moz-scrollbar-end-backward: 0");
+  expression_should_not_be_parseable("-moz-scrollbar-end-forward: 0");
+  expression_should_not_be_parseable("-moz-scrollbar-thumb-proportional: 0");
   expression_should_be_parseable("-moz-overlay-scrollbars: 0");
   expression_should_be_parseable("-moz-windows-default-theme: 0");
   expression_should_be_parseable("-moz-mac-graphite-theme: 0");
@@ -665,11 +665,11 @@ function run() {
   expression_should_be_parseable("-moz-touch-enabled: 0");
   expression_should_be_parseable("-moz-swipe-animation-enabled: 0");
 
-  expression_should_be_parseable("-moz-scrollbar-start-backward: 1");
-  expression_should_be_parseable("-moz-scrollbar-start-forward: 1");
-  expression_should_be_parseable("-moz-scrollbar-end-backward: 1");
-  expression_should_be_parseable("-moz-scrollbar-end-forward: 1");
-  expression_should_be_parseable("-moz-scrollbar-thumb-proportional: 1");
+  expression_should_not_be_parseable("-moz-scrollbar-start-backward: 1");
+  expression_should_not_be_parseable("-moz-scrollbar-start-forward: 1");
+  expression_should_not_be_parseable("-moz-scrollbar-end-backward: 1");
+  expression_should_not_be_parseable("-moz-scrollbar-end-forward: 1");
+  expression_should_not_be_parseable("-moz-scrollbar-thumb-proportional: 1");
   expression_should_be_parseable("-moz-overlay-scrollbars: 1");
   expression_should_be_parseable("-moz-windows-default-theme: 1");
   expression_should_be_parseable("-moz-mac-graphite-theme: 1");
diff --git a/layout/xul/crashtests/crashtests.list b/layout/xul/crashtests/crashtests.list
index 3ee57d1c92fc..332facdbfd0f 100644
--- a/layout/xul/crashtests/crashtests.list
+++ b/layout/xul/crashtests/crashtests.list
@@ -1,12 +1,12 @@
 load 131008-1.xul
 load 137216-1.xul
-asserts-if(stylo,3) load 140218-1.xml
+asserts-if(stylo,3) load 140218-1.xml # bug 1397644
 load 151826-1.xul
 load 168724-1.xul
 load 189814-1.xul
 load 237787-1.xul
 load 265161-1.xul
-load 289410-1.xul
+asserts-if(stylo,3) load 289410-1.xul # bug 1397644
 load 290743.html
 load 291702-1.xul
 load 291702-2.xul
@@ -24,12 +24,12 @@ load 329327-1.xul
 load 329407-1.xml
 load 329477-1.xhtml
 load 336962-1.xul
-load 344228-1.xul
+asserts-if(stylo,3) load 344228-1.xul # bug 1397644
 load 346083-1.xul
 load 346281-1.xul
 load 350460.xul
 load 360642-1.xul
-load 365151.xul
+asserts-if(stylo,3-4) load 365151.xul # bug 1397644
 load 366112-1.xul
 asserts(0-50) load 366203-1.xul # bug 1217984
 load 367185-1.xhtml
@@ -70,7 +70,7 @@ load 430356-1.xhtml
 load 431738.xhtml
 load 432058-1.xul
 load 432068-1.xul
-load 432068-2.xul
+skip-if(stylo) load 432068-2.xul # bug 1407865
 load 433296-1.xul
 load 433429.xul
 load 434458-1.xul
@@ -90,7 +90,7 @@ load 508927-1.xul
 load 508927-2.xul
 load 514300-1.xul
 load 536931-1.xhtml
-load 538308-1.xul
+asserts-if(stylo,4) load 538308-1.xul # bug 1397644
 load 557174-1.xml
 load 564705-1.xul
 load 583957-1.html
diff --git a/layout/xul/grid/reftests/reftest.list b/layout/xul/grid/reftests/reftest.list
index eb414f906055..18861868d58b 100644
--- a/layout/xul/grid/reftests/reftest.list
+++ b/layout/xul/grid/reftests/reftest.list
@@ -1,18 +1,19 @@
-== row-sizing-1.xul row-sizing-1-ref.xul
-== column-sizing-1.xul column-sizing-1-ref.xul
-== row-or-column-sizing-1.xul row-or-column-sizing-2.xul
-== row-or-column-sizing-1.xul row-or-column-sizing-3.xul
-== row-or-column-sizing-1.xul row-or-column-sizing-4.xul
-fuzzy-if(skiaContent,1,60000) == z-order-1.xul z-order-1-ref.xul
-fuzzy-if(skiaContent,1,60000) == z-order-2.xul z-order-2-ref.xul
-fuzzy-if(skiaContent,1,60000) == not-full-basic.xul not-full-basic-ref.xhtml
-fuzzy-if(skiaContent,1,110000) == not-full-grid-pack-align.xul not-full-basic-ref.xhtml
-fuzzy-if(skiaContent,1,30000) == not-full-row-group-align.xul not-full-row-group-align-ref.xhtml # does anyone want/need this behavior?
-fuzzy-if(skiaContent,1,10000) == not-full-row-group-pack.xul not-full-row-group-pack-ref.xhtml
-fuzzy-if(skiaContent,1,50000) == not-full-row-group-direction.xul not-full-row-group-direction-ref.xhtml
-fuzzy-if(skiaContent,1,60000) == not-full-row-leaf-align.xul not-full-basic-ref.xhtml
-fuzzy-if(skiaContent,1,50000) == not-full-row-leaf-pack.xul not-full-row-leaf-pack-ref.xhtml
-fuzzy-if(skiaContent,1,80000) == not-full-row-leaf-direction.xul not-full-row-leaf-pack-ref.xhtml
-random-if(transparentScrollbars) fuzzy-if(OSX==1010,1,565) == scrollable-columns.xul scrollable-columns-ref.xhtml # bug 650597
+fails-if(styloVsGecko) == row-sizing-1.xul row-sizing-1-ref.xul # bug 1408235 & bug 1408811
+fails-if(styloVsGecko) == column-sizing-1.xul column-sizing-1-ref.xul # bug 1408235 & bug 1408811
+fails-if(styloVsGecko) == row-or-column-sizing-1.xul row-or-column-sizing-2.xul # bug 1408811
+fails-if(styloVsGecko) == row-or-column-sizing-1.xul row-or-column-sizing-3.xul # bug 1408811
+fails-if(styloVsGecko) == row-or-column-sizing-1.xul row-or-column-sizing-4.xul # bug 1408811
+fuzzy-if(skiaContent,1,60000) fails-if(styloVsGecko) == z-order-1.xul z-order-1-ref.xul # bug 1408235
+fuzzy-if(skiaContent,1,60000) fails-if(styloVsGecko) == z-order-2.xul z-order-2-ref.xul # bug 1408235
+# stylo failures on the 8 tests below are all from bug 1408235
+fuzzy-if(skiaContent,1,60000) fails-if(stylo||styloVsGecko) == not-full-basic.xul not-full-basic-ref.xhtml
+fuzzy-if(skiaContent,1,110000) fails-if(stylo||styloVsGecko) == not-full-grid-pack-align.xul not-full-basic-ref.xhtml
+fuzzy-if(skiaContent,1,30000) fails-if(stylo||styloVsGecko) == not-full-row-group-align.xul not-full-row-group-align-ref.xhtml # does anyone want/need this behavior?
+fuzzy-if(skiaContent,1,10000) fails-if(stylo||styloVsGecko) == not-full-row-group-pack.xul not-full-row-group-pack-ref.xhtml
+fuzzy-if(skiaContent,1,50000) fails-if(stylo||styloVsGecko) == not-full-row-group-direction.xul not-full-row-group-direction-ref.xhtml
+fuzzy-if(skiaContent,1,60000) fails-if(stylo||styloVsGecko) == not-full-row-leaf-align.xul not-full-basic-ref.xhtml
+fuzzy-if(skiaContent,1,50000) fails-if(stylo||styloVsGecko) == not-full-row-leaf-pack.xul not-full-row-leaf-pack-ref.xhtml
+fuzzy-if(skiaContent,1,80000) fails-if(stylo||styloVsGecko) == not-full-row-leaf-direction.xul not-full-row-leaf-pack-ref.xhtml
+random-if(transparentScrollbars) fuzzy-if(OSX==1010,1,565) fails-if(stylo&&!gtkWidget) == scrollable-columns.xul scrollable-columns-ref.xhtml # bug 650597, stylo: bug 1408235
 fails == scrollable-rows.xul scrollable-rows-ref.xhtml
-== sizing-2d.xul sizing-2d-ref.xul
+fails-if(styloVsGecko) == sizing-2d.xul sizing-2d-ref.xul # bug 1408235
diff --git a/layout/xul/reftest/reftest.list b/layout/xul/reftest/reftest.list
index 4a963de7d0c0..1ce9ecebbee0 100644
--- a/layout/xul/reftest/reftest.list
+++ b/layout/xul/reftest/reftest.list
@@ -1,6 +1,6 @@
-fails-if(Android) == textbox-multiline-noresize.xul textbox-multiline-ref.xul # reference is blank on Android (due to no native theme support?)
-!= textbox-multiline-resize.xul textbox-multiline-ref.xul
+fails-if(Android) fails-if(stylo||styloVsGecko) == textbox-multiline-noresize.xul textbox-multiline-ref.xul # reference is blank on Android (due to no native theme support?), stylo: bug 1408235 & bug 1408811
+fails-if(styloVsGecko) != textbox-multiline-resize.xul textbox-multiline-ref.xul # bug 1408235 & bug 1408811
 == popup-explicit-size.xul popup-explicit-size-ref.xul
-random-if(Android) fuzzy-if(webrender,128-128,168-168) == image-size.xul image-size-ref.xul
+random-if(Android) fuzzy-if(webrender,128-128,168-168) fails-if(stylo||styloVsGecko) == image-size.xul image-size-ref.xul # stylo: bug 1408235
 == image-scaling-min-height-1.xul image-scaling-min-height-1-ref.xul
-== textbox-text-transform.xul textbox-text-transform-ref.xul
+fails-if(stylo||styloVsGecko) == textbox-text-transform.xul textbox-text-transform-ref.xul # stylo: bug 1408235
diff --git a/layout/xul/test/mochitest.ini b/layout/xul/test/mochitest.ini
index 00738b55ec59..118c67606792 100644
--- a/layout/xul/test/mochitest.ini
+++ b/layout/xul/test/mochitest.ini
@@ -11,3 +11,4 @@ skip-if = toolkit == 'android'
 [test_resizer_incontent.xul]
 [test_splitter.xul]
 skip-if = toolkit == 'android' # no XUL theme
+fail-if = stylo # bug 1407863
diff --git a/layout/xul/tree/crashtests/crashtests.list b/layout/xul/tree/crashtests/crashtests.list
index 94c5aa37d0a2..5e3de4cc975d 100644
--- a/layout/xul/tree/crashtests/crashtests.list
+++ b/layout/xul/tree/crashtests/crashtests.list
@@ -1,24 +1,25 @@
-load 307298-1.xul
-load 309732-1.xul
-load 309732-2.xul
-load 366583-1.xul
-load 380217-1.xul
+# All stylo assertions below are bug 1397644
+asserts-if(stylo,3-4) load 307298-1.xul
+asserts-if(stylo,8) load 309732-1.xul
+asserts-if(stylo,8) load 309732-2.xul
+asserts-if(stylo,13-23) load 366583-1.xul
+asserts-if(stylo,6) load 380217-1.xul
 load 382444-1.html
 load 391178-1.xhtml
 load 391178-2.xul
 load 393665-1.xul
-load 399227-1.xul
-load 399227-2.xul
-asserts-if(stylo,3) load 399692-1.xhtml # bug 1324698
+asserts-if(stylo,12) load 399227-1.xul
+asserts-if(stylo,13) load 399227-2.xul
+asserts-if(stylo,3) load 399692-1.xhtml
 load 399715-1.xhtml
-load 409807-1.xul
-load 414170-1.xul
+asserts-if(stylo,3) load 409807-1.xul
+asserts-if(stylo,3) load 414170-1.xul
 load 430394-1.xul
-load 454186-1.xul
-asserts-if(stylo,3) load 479931-1.xhtml # bug 1324698
-load 509602-1.xul
-load 585815.html
+asserts-if(stylo,12) load 454186-1.xul
+asserts-if(stylo,3) load 479931-1.xhtml
+asserts-if(stylo,3) load 509602-1.xul
+asserts-if(stylo,27-34) load 585815.html
 load 601427.html
-load 730441-1.xul
-load 730441-2.xul
-load 730441-3.xul
+asserts-if(stylo,3) load 730441-1.xul
+asserts-if(stylo,3) load 730441-2.xul
+asserts-if(stylo,3) load 730441-3.xul
diff --git a/media/gmp-clearkey/0.1/gmp-clearkey.cpp b/media/gmp-clearkey/0.1/gmp-clearkey.cpp
index 010da241a675..6285f2a7a493 100644
--- a/media/gmp-clearkey/0.1/gmp-clearkey.cpp
+++ b/media/gmp-clearkey/0.1/gmp-clearkey.cpp
@@ -56,6 +56,11 @@ void* CreateCdmInstance(int cdm_interface_version,
 
   CK_LOGE("ClearKey CreateCDMInstance");
 
+  if (cdm_interface_version != cdm::ContentDecryptionModule_8::kVersion) {
+    CK_LOGE("ClearKey CreateCDMInstance failed due to requesting unsupported version %d.",
+            cdm_interface_version);
+    return nullptr;
+  }
 #ifdef ENABLE_WMF
   if (!wmf::EnsureLibs()) {
     CK_LOGE("Required libraries were not found");
diff --git a/mobile/android/app/build.gradle b/mobile/android/app/build.gradle
index 81c903f8fb1d..4c1f434683d2 100644
--- a/mobile/android/app/build.gradle
+++ b/mobile/android/app/build.gradle
@@ -355,6 +355,10 @@ android.applicationVariants.all { variant ->
     }
 }
 
+android.applicationVariants.all { variant ->
+    configureVariantWithJNIWrappers(variant, "Fennec")
+}
+
 apply plugin: 'spoon'
 
 spoon {
diff --git a/mobile/android/app/mobile.js b/mobile/android/app/mobile.js
index 98cc4153660f..c1dacd5b96ba 100644
--- a/mobile/android/app/mobile.js
+++ b/mobile/android/app/mobile.js
@@ -567,18 +567,13 @@ pref("apz.fling_curve_threshold_inches_per_ms", "0.01");
 // apz.fling_friction and apz.fling_stopped_threshold are currently ignored by Fennec.
 pref("apz.fling_friction", "0.004");
 pref("apz.fling_stopped_threshold", "0.0");
+pref("apz.frame_delay.enabled", true);
 pref("apz.max_velocity_inches_per_ms", "0.07");
 pref("apz.overscroll.enabled", true);
 pref("apz.second_tap_tolerance", "0.3");
 pref("apz.touch_move_tolerance", "0.03");
 pref("apz.touch_start_tolerance", "0.06");
 
-#ifdef NIGHTLY_BUILD
-pref("apz.frame_delay.enabled", true);
-#else
-pref("apz.frame_delay.enabled", false);
-#endif
-
 pref("layers.progressive-paint", true);
 pref("layers.low-precision-buffer", true);
 pref("layers.low-precision-resolution", "0.25");
diff --git a/mobile/android/base/Makefile.in b/mobile/android/base/Makefile.in
index e1b4e180ae2d..c4d2d1bad628 100644
--- a/mobile/android/base/Makefile.in
+++ b/mobile/android/base/Makefile.in
@@ -25,6 +25,8 @@ GARBAGE += \
 
 GARBAGE_DIRS += classes db jars res sync services generated
 
+gradle_dir := $(topobjdir)/gradle/build/mobile/android
+
 # The bootclasspath is functionally identical to the classpath, but allows the
 # classes given to redefine classes in core packages, such as java.lang.
 # android.jar is here as it provides Android's definition of the Java Standard
@@ -141,6 +143,7 @@ uniq = $(if $1,$(firstword $1) $(call uniq,$(filter-out $(firstword $1),$1)))
 java_bundled_libs := $(call uniq,$(java_bundled_libs))
 java_bundled_libs := $(subst $(NULL) ,:,$(strip $(java_bundled_libs)))
 
+ifndef MOZ_BUILD_MOBILE_ANDROID_WITH_GRADLE
 GECKOVIEW_JARS = \
   constants.jar \
   gecko-R.jar \
@@ -166,8 +169,6 @@ ifdef MOZ_ANDROID_MMA
 GECKOVIEW_JARS += gecko-thirdparty-leanplum_sdk.jar
 endif
 
-geckoview_jars_classpath := $(subst $(NULL) ,:,$(strip $(GECKOVIEW_JARS)))
-
 FENNEC_JARS = \
   gecko-browser.jar \
   gecko-thirdparty.jar \
@@ -182,6 +183,17 @@ ifdef MOZ_ANDROID_MLS_STUMBLER
 FENNEC_JARS += ../stumbler/stumbler.jar
 endif
 
+else # MOZ_BUILD_MOBILE_ANDROID_WITH_GRADLE
+
+GECKOVIEW_JARS := $(gradle_dir)/geckoview/intermediates/bundles/debug/classes.jar
+FENNEC_JARS := $(gradle_dir)/app/intermediates/packaged/officialPhoton/debug/classes.jar
+
+$(GECKOVIEW_JARS): .gradle.deps
+$(FENNEC_JARS): .gradle.deps
+
+endif # MOZ_BUILD_MOBILE_ANDROID_WITH_GRADLE
+
+geckoview_jars_classpath := $(subst $(NULL) ,:,$(strip $(GECKOVIEW_JARS)))
 
 # All the jars we're compiling from source. (not to be confused with
 # java_bundled_libs, which holds the jars which we're including as binaries).
@@ -228,22 +240,30 @@ endif # MOZ_INSTALL_TRACKING
 
 library_jars := $(subst $(NULL) ,:,$(strip $(library_jars)))
 
-gradle_dir := $(topobjdir)/gradle/build/mobile/android
-
 ifdef MOZ_BUILD_MOBILE_ANDROID_WITH_GRADLE
 .gradle.deps: .aapt.deps FORCE
 	@$(TOUCH) $@
 	$(topsrcdir)/mach gradle \
-		app:assembleOfficialPhotonDebug app:assembleOfficialPhotonDebugAndroidTest -x lint
+		geckoview:generateJNIWrappersForGeneratedRelease \
+		app:generateJNIWrappersForFennecOfficialPhotonDebug \
+		app:assembleOfficialPhotonDebug \
+		app:assembleOfficialPhotonDebugAndroidTest \
+		-x lint
 
 classes.dex: .gradle.deps
 	$(REPORT_BUILD)
 	cp $(gradle_dir)/app/intermediates/transforms/dex/officialPhoton/debug/folders/1000/1f/main/classes.dex $@
+
+GeneratedJNIWrappers.cpp GeneratedJNIWrappers.h GeneratedJNINatives.h : .gradle.deps
+	$(REPORT_BUILD)
+
+FennecJNIWrappers.cpp FennecJNIWrappers.h FennecJNINatives.h: .gradle.deps
+	$(REPORT_BUILD)
+
 else
 classes.dex: .proguard.deps
 	$(REPORT_BUILD)
 	$(DX) --dex --output=classes.dex --force-jumbo jars-proguarded
-endif
 
 ifdef MOZ_DISABLE_PROGUARD
   PROGUARD_PASSES=0
@@ -328,6 +348,8 @@ FennecJNIWrappers.cpp: $(ANNOTATION_PROCESSOR_JAR_FILES) $(FENNEC_JARS)
 		org.mozilla.gecko.annotationProcessors.AnnotationProcessor \
 		Fennec $(FENNEC_JARS)
 
+endif # MOZ_BUILD_MOBILE_ANDROID_WITH_GRADLE
+
 include $(topsrcdir)/config/rules.mk
 
 not_android_res_files := \
@@ -536,7 +558,6 @@ endif
 #   GeneratedJNIWrappers.h and GeneratedJNINatives.h
 # FennecJNIWrappers.cpp target also generates
 #   FennecJNIWrappers.h and FennecJNINatives.h
-ifndef MOZ_BUILD_MOBILE_ANDROID_WITH_GRADLE
 
 # List of build flags used by auto-generated JNI bindings (through the
 # @BuildFlag annotation in Java). For example, add a "MOZ_FOO \" line to this
@@ -586,11 +607,12 @@ libs:: FennecJNIWrappers.cpp
 	  echo '* Repeat the build, and check in any changes.       *' && \
 	  echo '*****************************************************' && \
 	  exit 1)
-endif
 
 libs:: classes.dex
 	$(INSTALL) classes.dex $(FINAL_TARGET)
 
+ifndef MOZ_BUILD_MOBILE_ANDROID_WITH_GRADLE
+
 # Generate Java binder interfaces from AIDL files.
 GECKOVIEW_AIDLS = \
   org/mozilla/gecko/IGeckoEditableChild.aidl \
@@ -623,3 +645,5 @@ fennec_aidl_targets := $(addprefix $(fennec_aidl_target_path)/,$(patsubst %.aidl
 $(fennec_aidl_targets): $(fennec_aidl_target_path)/%.java: $(fennec_aidl_src_path)/%.aidl
 	@echo "Processing AIDL: $< => $@"
 	$(AIDL) -p$(ANDROID_SDK)/framework.aidl -I$(fennec_aidl_src_path) -I$(geckoview_aidl_src_path) -o$(fennec_aidl_target_path) $<
+
+endif # MOZ_BUILD_MOBILE_ANDROID_WITH_GRADLE
diff --git a/mobile/android/base/java/org/mozilla/gecko/util/ShortcutUtils.java b/mobile/android/base/java/org/mozilla/gecko/util/ShortcutUtils.java
index 78e5daa302e8..31715da93caf 100644
--- a/mobile/android/base/java/org/mozilla/gecko/util/ShortcutUtils.java
+++ b/mobile/android/base/java/org/mozilla/gecko/util/ShortcutUtils.java
@@ -5,6 +5,7 @@
 package org.mozilla.gecko.util;
 
 import android.annotation.TargetApi;
+import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentSender;
@@ -89,10 +90,15 @@ public class ShortcutUtils {
             Object info = builderCls.getDeclaredMethod("build")
                 .invoke(builder);
 
+            final Intent intent = new Intent(Intent.ACTION_MAIN);
+            intent.addCategory(Intent.CATEGORY_HOME);
+            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+            final PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
+            final IntentSender intentSender = pendingIntent.getIntentSender();
             mgrCls.getDeclaredMethod("requestPinShortcut",
                                      info.getClass(),
                                      IntentSender.class)
-                .invoke(mgr, info, null);
+                .invoke(mgr, info, intentSender);
         } catch (Exception e) {
             Log.e(LOG_TAG, "Failed to pin shortcut: ", e);
         }
diff --git a/mobile/android/geckoview/build.gradle b/mobile/android/geckoview/build.gradle
index 1dce2820235a..cce726735345 100644
--- a/mobile/android/geckoview/build.gradle
+++ b/mobile/android/geckoview/build.gradle
@@ -167,6 +167,10 @@ android.libraryVariants.all { variant ->
     }
 }
 
+android.libraryVariants.all { variant ->
+    configureVariantWithJNIWrappers(variant, "Generated")
+}
+
 apply plugin: 'maven'
  
 uploadArchives {
diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/JellyBeanAsyncCodec.java b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/JellyBeanAsyncCodec.java
index 5ab2a6ef5490..b94a077db807 100644
--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/JellyBeanAsyncCodec.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/JellyBeanAsyncCodec.java
@@ -311,10 +311,14 @@ final class JellyBeanAsyncCodec implements AsyncCodec {
 
     @Override
     public boolean isTunneledPlaybackSupported(final String mimeType) {
-        return android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP
-               && mCodec.getCodecInfo()
-                        .getCapabilitiesForType(mimeType)
-                        .isFeatureSupported(CodecCapabilities.FEATURE_TunneledPlayback);
+        try {
+            return android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP
+                   && mCodec.getCodecInfo()
+                            .getCapabilitiesForType(mimeType)
+                            .isFeatureSupported(CodecCapabilities.FEATURE_TunneledPlayback);
+        } catch (Exception e) {
+            return false;
+        }
     }
 
     private void assertCallbacks() {
diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/LollipopAsyncCodec.java b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/LollipopAsyncCodec.java
index 519e5adb2fb6..503de3237e68 100644
--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/LollipopAsyncCodec.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/LollipopAsyncCodec.java
@@ -154,9 +154,13 @@ import java.nio.ByteBuffer;
 
     @Override
     public boolean isTunneledPlaybackSupported(final String mimeType) {
-        return mCodec.getCodecInfo()
-                     .getCapabilitiesForType(mimeType)
-                     .isFeatureSupported(CodecCapabilities.FEATURE_TunneledPlayback);
+        try {
+            return mCodec.getCodecInfo()
+                         .getCapabilitiesForType(mimeType)
+                         .isFeatureSupported(CodecCapabilities.FEATURE_TunneledPlayback);
+        } catch (Exception e) {
+            return false;
+        }
     }
 
     @Override
diff --git a/mobile/android/gradle/with_gecko_binaries.gradle b/mobile/android/gradle/with_gecko_binaries.gradle
index 630826822106..6965162fb210 100644
--- a/mobile/android/gradle/with_gecko_binaries.gradle
+++ b/mobile/android/gradle/with_gecko_binaries.gradle
@@ -121,3 +121,54 @@ ext.configureVariantWithGeckoBinaries = { variant ->
     android.sourceSets."${sourceSet}".assets.srcDir syncAssetsFromDistDir.destinationDir
     android.sourceSets."${sourceSet}".jniLibs.srcDir syncLibsFromDistDir.destinationDir
 }
+
+ext.configureVariantWithJNIWrappers = { variant, module ->
+
+    def jarTask = tasks.findByName("jar${variant.name.capitalize()}Classes")
+    if (jarTask == null) {
+        jarTask = tasks.findByName("package${variant.name.capitalize()}JarArtifact")
+    }
+    if (jarTask == null) {
+        throw new GradleException("Jar task not found: \"jar${variant.name.capitalize()}Classes\"\t\"package${variant.name.capitalize()}JarArtifact\"" )
+    }
+    if (jarTask.outputs.files.size() != 1) {
+        throw new GradleException("Jar task output multiple files other than one single jar")
+    }
+
+    // At configuration time, the classpath of dependencies with internal_impl
+    // JAR files may not be correct.  This manifests in
+    //
+    // 'Exception in thread "main" java.lang.NoClassDefFoundError: android/support/v4/app/ActivityCompatApi23$RequestPermissionsRequestCodeValidator'
+    //
+    // when running |mach gradle clean app:generateJNI...|.  We work around this
+    // by configuring the classpath at evaluation-time, not configuration-time.
+    //
+    // The specific dependency on the `prepareDependencies` task may not be
+    // necessary, but commits like
+    // https://github.com/evant/gradle-retrolambda/commit/15108c65ee43be499a1359d9d4f88b0851d46769
+    // suggest that it is.  It certainly doesn't hurt.
+    def prepareDependenciesTask = tasks.getByName("prepare${variant.name.capitalize()}Dependencies")
+
+    def wrapperTask = task("generateJNIWrappersFor${module}${variant.name.capitalize()}", type: JavaExec) {
+        classpath "${topobjdir}/build/annotationProcessors/annotationProcessors.jar"
+
+        // Configure the classpath at evaluation-time, not at
+        // configuration-time: see above comment.
+        doFirst {
+            classpath variant.javaCompile.classpath
+            // Include android.jar.
+            classpath variant.javaCompile.options.bootClasspath
+        }
+
+        main = 'org.mozilla.gecko.annotationProcessors.AnnotationProcessor'
+        args module
+        args jarTask.outputs.files.iterator().next()
+
+        workingDir "${topobjdir}/mobile/android/base"
+
+        dependsOn jarTask
+        dependsOn prepareDependenciesTask
+    }
+
+    variant.assemble.dependsOn wrapperTask
+}
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 648725eb3495..8d70067b2900 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -5336,6 +5336,10 @@ pref("dom.vr.puppet.enabled", false);
 // Allow displaying the result of vr submitframe (0: disable, 1: store the
 // result as a base64 image, 2: show it on the screen).
 pref("dom.vr.puppet.submitframe", 0);
+// The number of milliseconds since last frame start before triggering a new frame.
+// When content is failing to submit frames on time or the lower level VR platform API's
+// are rejecting frames, it determines the rate at which RAF callbacks will be called.
+pref("dom.vr.display.rafMaxDuration", 50);
 // VR test system.
 pref("dom.vr.test.enabled", false);
 
diff --git a/moz.configure b/moz.configure
index 4ea93b7a3d15..da81abffb532 100755
--- a/moz.configure
+++ b/moz.configure
@@ -14,17 +14,6 @@ include('build/moz.configure/init.configure')
 # - Spidermonkey-specific options and rules should go in js/moz.configure.
 # - etc.
 
-# Multiprocess Firefox Testing UI - Nightly and Aurora
-# To be removed in Bug 1003313
-@depends(milestone)
-def e10s_testing_only(milestone):
-    if not milestone.is_release_or_beta:
-        return True
-
-set_config('E10S_TESTING_ONLY', e10s_testing_only)
-set_define('E10S_TESTING_ONLY', e10s_testing_only)
-
-
 option('--enable-artifact-builds', env='MOZ_ARTIFACT_BUILDS',
        help='Download and use prebuilt binary artifacts.')
 
diff --git a/netwerk/base/Predictor.cpp b/netwerk/base/Predictor.cpp
index 7b89fdfa8535..5790eeb7ce90 100644
--- a/netwerk/base/Predictor.cpp
+++ b/netwerk/base/Predictor.cpp
@@ -2586,7 +2586,7 @@ Predictor::UpdateCacheability(nsIURI *sourceURI, nsIURI *targetURI,
                               uint32_t httpStatus,
                               nsHttpRequestHead &requestHead,
                               nsHttpResponseHead *responseHead,
-                              nsILoadContextInfo *lci)
+                              nsILoadContextInfo *lci, bool isTracking)
 {
   MOZ_ASSERT(NS_IsMainThread());
 
@@ -2610,7 +2610,8 @@ Predictor::UpdateCacheability(nsIURI *sourceURI, nsIURI *targetURI,
     nsAutoCString method;
     requestHead.Method(method);
     self->UpdateCacheabilityInternal(sourceURI, targetURI, httpStatus,
-                                     method, *lci->OriginAttributesPtr());
+                                     method, *lci->OriginAttributesPtr(),
+                                     isTracking);
   }
 }
 
@@ -2618,7 +2619,8 @@ void
 Predictor::UpdateCacheabilityInternal(nsIURI *sourceURI, nsIURI *targetURI,
                                       uint32_t httpStatus,
                                       const nsCString &method,
-                                      const OriginAttributes& originAttributes)
+                                      const OriginAttributes& originAttributes,
+                                      bool isTracking)
 {
   PREDICTOR_LOG(("Predictor::UpdateCacheability httpStatus=%u", httpStatus));
 
@@ -2655,7 +2657,8 @@ Predictor::UpdateCacheabilityInternal(nsIURI *sourceURI, nsIURI *targetURI,
                        nsICacheStorage::OPEN_SECRETLY |
                        nsICacheStorage::CHECK_MULTITHREADED;
   RefPtr<Predictor::CacheabilityAction> action =
-    new Predictor::CacheabilityAction(targetURI, httpStatus, method, this);
+    new Predictor::CacheabilityAction(targetURI, httpStatus, method, isTracking,
+                                      this);
   nsAutoCString uri;
   targetURI->GetAsciiSpec(uri);
   PREDICTOR_LOG(("    uri=%s action=%p", uri.get(), action.get()));
@@ -2730,7 +2733,9 @@ Predictor::CacheabilityAction::OnCacheEntryAvailable(nsICacheEntry *entry,
     }
 
     if (strTargetURI.Equals(uri)) {
-      if (mHttpStatus == 200 && mMethod.EqualsLiteral("GET") && !hasQueryString) {
+      if (mHttpStatus == 200 && mMethod.EqualsLiteral("GET") &&
+          !hasQueryString &&
+          !mIsTracking) {
         PREDICTOR_LOG(("    marking %s cacheable", key));
         flags |= FLAG_PREFETCHABLE;
       } else {
diff --git a/netwerk/base/Predictor.h b/netwerk/base/Predictor.h
index beca80ace852..f0533cbf4643 100644
--- a/netwerk/base/Predictor.h
+++ b/netwerk/base/Predictor.h
@@ -66,7 +66,7 @@ public:
                                  uint32_t httpStatus,
                                  nsHttpRequestHead &requestHead,
                                  nsHttpResponseHead *reqponseHead,
-                                 nsILoadContextInfo *lci);
+                                 nsILoadContextInfo *lci, bool isTracking);
 
 private:
   virtual ~Predictor();
@@ -139,10 +139,12 @@ private:
     NS_DECL_NSICACHEENTRYMETADATAVISITOR
 
     CacheabilityAction(nsIURI *targetURI, uint32_t httpStatus,
-                       const nsCString &method, Predictor *predictor)
+                       const nsCString &method, bool isTracking,
+                       Predictor *predictor)
       :mTargetURI(targetURI)
       ,mHttpStatus(httpStatus)
       ,mMethod(method)
+      ,mIsTracking(isTracking)
       ,mPredictor(predictor)
     { }
 
@@ -152,6 +154,7 @@ private:
     nsCOMPtr<nsIURI> mTargetURI;
     uint32_t mHttpStatus;
     nsCString mMethod;
+    bool mIsTracking;
     RefPtr<Predictor> mPredictor;
     nsTArray<nsCString> mKeysToCheck;
     nsTArray<nsCString> mValuesToCheck;
@@ -422,7 +425,8 @@ private:
   // and httpStatus is the status code we got while loading targetURI.
   void UpdateCacheabilityInternal(nsIURI *sourceURI, nsIURI *targetURI,
                                   uint32_t httpStatus, const nsCString &method,
-                                  const OriginAttributes& originAttributes);
+                                  const OriginAttributes& originAttributes,
+                                  bool isTracking);
 
   // Make sure our prefs are in their expected range of values
   void SanitizePrefs();
diff --git a/netwerk/protocol/device/nsDeviceChannel.cpp b/netwerk/protocol/device/nsDeviceChannel.cpp
index a068b9e08f52..3b38d0d12728 100644
--- a/netwerk/protocol/device/nsDeviceChannel.cpp
+++ b/netwerk/protocol/device/nsDeviceChannel.cpp
@@ -77,8 +77,6 @@ nsDeviceChannel::OpenContentStream(bool aAsync,
   nsCOMPtr<nsIURI> uri = nsBaseChannel::URI();
   *aStream = nullptr;
   *aChannel = nullptr;
-  NS_NAMED_LITERAL_CSTRING(width, "width=");
-  NS_NAMED_LITERAL_CSTRING(height, "height=");
 
   nsAutoCString spec;
   nsresult rv = uri->GetSpec(spec);
diff --git a/netwerk/protocol/http/nsHttpChannel.cpp b/netwerk/protocol/http/nsHttpChannel.cpp
index 90e7235fe0e8..a4a82a270798 100644
--- a/netwerk/protocol/http/nsHttpChannel.cpp
+++ b/netwerk/protocol/http/nsHttpChannel.cpp
@@ -2354,7 +2354,7 @@ nsHttpChannel::ProcessResponse()
         nsCOMPtr<nsILoadContextInfo> lci = GetLoadContextInfo(this);
         mozilla::net::Predictor::UpdateCacheability(referrer, mURI, httpStatus,
                                                     mRequestHead, mResponseHead,
-                                                    lci);
+                                                    lci, mIsTrackingResource);
     }
 
     if (mTransaction && mTransaction->ProxyConnectFailed()) {
diff --git a/security/certverifier/ExtendedValidation.cpp b/security/certverifier/ExtendedValidation.cpp
index de14bd500f21..eb74b226e4e6 100644
--- a/security/certverifier/ExtendedValidation.cpp
+++ b/security/certverifier/ExtendedValidation.cpp
@@ -176,41 +176,6 @@ static const struct EVInfo kEVInfos[] = {
     "FlN3aXNzU2lnbiBHb2xkIENBIC0gRzI=",
     "ALtAHEP1Xk+w",
   },
-  {
-    // CN=StartCom Certification Authority,OU=Secure Digital Certificate Signing,O=StartCom Ltd.,C=IL
-    "1.3.6.1.4.1.23223.1.1.1",
-    "StartCom EV OID",
-    { 0xC7, 0x66, 0xA9, 0xBE, 0xF2, 0xD4, 0x07, 0x1C, 0x86, 0x3A, 0x31,
-      0xAA, 0x49, 0x20, 0xE8, 0x13, 0xB2, 0xD1, 0x98, 0x60, 0x8C, 0xB7,
-      0xB7, 0xCF, 0xE2, 0x11, 0x43, 0xB8, 0x36, 0xDF, 0x09, 0xEA },
-    "MH0xCzAJBgNVBAYTAklMMRYwFAYDVQQKEw1TdGFydENvbSBMdGQuMSswKQYDVQQL"
-    "EyJTZWN1cmUgRGlnaXRhbCBDZXJ0aWZpY2F0ZSBTaWduaW5nMSkwJwYDVQQDEyBT"
-    "dGFydENvbSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eQ==",
-    "AQ==",
-  },
-  {
-    // CN=StartCom Certification Authority,OU=Secure Digital Certificate Signing,O=StartCom Ltd.,C=IL
-    "1.3.6.1.4.1.23223.1.1.1",
-    "StartCom EV OID",
-    { 0xE1, 0x78, 0x90, 0xEE, 0x09, 0xA3, 0xFB, 0xF4, 0xF4, 0x8B, 0x9C,
-      0x41, 0x4A, 0x17, 0xD6, 0x37, 0xB7, 0xA5, 0x06, 0x47, 0xE9, 0xBC,
-      0x75, 0x23, 0x22, 0x72, 0x7F, 0xCC, 0x17, 0x42, 0xA9, 0x11 },
-    "MH0xCzAJBgNVBAYTAklMMRYwFAYDVQQKEw1TdGFydENvbSBMdGQuMSswKQYDVQQL"
-    "EyJTZWN1cmUgRGlnaXRhbCBDZXJ0aWZpY2F0ZSBTaWduaW5nMSkwJwYDVQQDEyBT"
-    "dGFydENvbSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eQ==",
-    "LQ==",
-  },
-  {
-    // CN=StartCom Certification Authority G2,O=StartCom Ltd.,C=IL
-    "1.3.6.1.4.1.23223.1.1.1",
-    "StartCom EV OID",
-    { 0xC7, 0xBA, 0x65, 0x67, 0xDE, 0x93, 0xA7, 0x98, 0xAE, 0x1F, 0xAA,
-      0x79, 0x1E, 0x71, 0x2D, 0x37, 0x8F, 0xAE, 0x1F, 0x93, 0xC4, 0x39,
-      0x7F, 0xEA, 0x44, 0x1B, 0xB7, 0xCB, 0xE6, 0xFD, 0x59, 0x95 },
-    "MFMxCzAJBgNVBAYTAklMMRYwFAYDVQQKEw1TdGFydENvbSBMdGQuMSwwKgYDVQQD"
-    "EyNTdGFydENvbSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eSBHMg==",
-    "Ow==",
-  },
   {
     // CN=VeriSign Class 3 Public Primary Certification Authority - G5,OU="(c) 2006 VeriSign, Inc. - For authorized use only",OU=VeriSign Trust Network,O="VeriSign, Inc.",C=US
     "2.16.840.1.113733.1.7.23.6",
@@ -708,28 +673,6 @@ static const struct EVInfo kEVInfos[] = {
     "YXRpb24gUm9vdCBDQQ==",
     "VwoRl0LE48w=",
   },
-  {
-    // CN=Certification Authority of WoSign,O=WoSign CA Limited,C=CN
-    "1.3.6.1.4.1.36305.2",
-    "WoSign EV OID",
-    { 0x4B, 0x22, 0xD5, 0xA6, 0xAE, 0xC9, 0x9F, 0x3C, 0xDB, 0x79, 0xAA,
-      0x5E, 0xC0, 0x68, 0x38, 0x47, 0x9C, 0xD5, 0xEC, 0xBA, 0x71, 0x64,
-      0xF7, 0xF2, 0x2D, 0xC1, 0xD6, 0x5F, 0x63, 0xD8, 0x57, 0x08 },
-    "MFUxCzAJBgNVBAYTAkNOMRowGAYDVQQKExFXb1NpZ24gQ0EgTGltaXRlZDEqMCgG"
-    "A1UEAxMhQ2VydGlmaWNhdGlvbiBBdXRob3JpdHkgb2YgV29TaWdu",
-    "XmjWEXGUY1BWAGjzPsnFkQ==",
-  },
-  {
-    // CN=CA ...............,O=WoSign CA Limited,C=CN
-    "1.3.6.1.4.1.36305.2",
-    "WoSign EV OID",
-    { 0xD6, 0xF0, 0x34, 0xBD, 0x94, 0xAA, 0x23, 0x3F, 0x02, 0x97, 0xEC,
-      0xA4, 0x24, 0x5B, 0x28, 0x39, 0x73, 0xE4, 0x47, 0xAA, 0x59, 0x0F,
-      0x31, 0x0C, 0x77, 0xF4, 0x8F, 0xDF, 0x83, 0x11, 0x22, 0x54 },
-    "MEYxCzAJBgNVBAYTAkNOMRowGAYDVQQKExFXb1NpZ24gQ0EgTGltaXRlZDEbMBkG"
-    "A1UEAwwSQ0Eg5rKD6YCa5qC56K+B5Lmm",
-    "UHBrzdgT/BtOOzNy0hFIjQ==",
-  },
   {
     // CN=DigiCert Assured ID Root G2,OU=www.digicert.com,O=DigiCert Inc,C=US
     "2.16.840.1.114412.2.1",
@@ -911,28 +854,6 @@ static const struct EVInfo kEVInfos[] = {
     "aWNhdGlvbiBBdXRob3JpdHkxFTATBgNVBAMMDENGQ0EgRVYgUk9PVA==",
     "GErM1g==",
   },
-  {
-    // CN=Certification Authority of WoSign G2,O=WoSign CA Limited,C=CN
-    "1.3.6.1.4.1.36305.2",
-    "WoSign EV OID",
-    { 0xD4, 0x87, 0xA5, 0x6F, 0x83, 0xB0, 0x74, 0x82, 0xE8, 0x5E, 0x96,
-      0x33, 0x94, 0xC1, 0xEC, 0xC2, 0xC9, 0xE5, 0x1D, 0x09, 0x03, 0xEE,
-      0x94, 0x6B, 0x02, 0xC3, 0x01, 0x58, 0x1E, 0xD9, 0x9E, 0x16 },
-    "MFgxCzAJBgNVBAYTAkNOMRowGAYDVQQKExFXb1NpZ24gQ0EgTGltaXRlZDEtMCsG"
-    "A1UEAxMkQ2VydGlmaWNhdGlvbiBBdXRob3JpdHkgb2YgV29TaWduIEcy",
-    "ayXaioidfLwPBbOxemFFRA==",
-  },
-  {
-    // CN=CA WoSign ECC Root,O=WoSign CA Limited,C=CN
-    "1.3.6.1.4.1.36305.2",
-    "WoSign EV OID",
-    { 0x8B, 0x45, 0xDA, 0x1C, 0x06, 0xF7, 0x91, 0xEB, 0x0C, 0xAB, 0xF2,
-      0x6B, 0xE5, 0x88, 0xF5, 0xFB, 0x23, 0x16, 0x5C, 0x2E, 0x61, 0x4B,
-      0xF8, 0x85, 0x56, 0x2D, 0x0D, 0xCE, 0x50, 0xB2, 0x9B, 0x02 },
-    "MEYxCzAJBgNVBAYTAkNOMRowGAYDVQQKExFXb1NpZ24gQ0EgTGltaXRlZDEbMBkG"
-    "A1UEAxMSQ0EgV29TaWduIEVDQyBSb290",
-    "aEpYcIBr8I8C+vbe6LCQkA==",
-  },
   {
     // OU=Security Communication RootCA2,O="SECOM Trust Systems CO.,LTD.",C=JP
     "1.2.392.200091.100.721.1",
diff --git a/security/sandbox/linux/SandboxFilter.cpp b/security/sandbox/linux/SandboxFilter.cpp
index 687eef12bc5b..f4f94e93c539 100644
--- a/security/sandbox/linux/SandboxFilter.cpp
+++ b/security/sandbox/linux/SandboxFilter.cpp
@@ -533,11 +533,6 @@ public:
     : mBroker(aBroker),
       mSyscallWhitelist(aSyscallWhitelist) {}
   ~ContentSandboxPolicy() override = default;
-  ResultExpr PrctlPolicy() const override {
-    // Ideally this should be restricted to a whitelist, but content
-    // uses enough things that it's not trivial to determine it.
-    return Allow();
-  }
   Maybe<ResultExpr> EvaluateSocketCall(int aCall) const override {
     switch(aCall) {
     case SYS_RECVFROM:
@@ -714,6 +709,10 @@ public:
 #endif
       return Allow();
 
+#ifdef MOZ_ALSA
+    case __NR_ioctl:
+      return Allow();
+#else
     case __NR_ioctl: {
       static const unsigned long kTypeMask = _IOC_TYPEMASK << _IOC_TYPESHIFT;
       static const unsigned long kTtyIoctls = TIOCSTI & kTypeMask;
@@ -734,11 +733,15 @@ public:
         // ffmpeg, and anything else that calls isatty(), will be told
         // that nothing is a typewriter:
         .ElseIf(request == TCGETS, Error(ENOTTY))
+        // Bug 1408498: libgio uses FIONREAD on inotify fds.
+        // (We should stop using inotify: bug 1408497.)
+        .ElseIf(request == FIONREAD, Allow())
         // Allow anything that isn't a tty ioctl, for now; bug 1302711
         // will cover changing this to a default-deny policy.
         .ElseIf(shifted_type != kTtyIoctls, Allow())
         .Else(SandboxPolicyCommon::EvaluateSyscall(sysno));
     }
+#endif // !MOZ_ALSA
 
     CASES_FOR_fcntl:
       // Some fcntls have significant side effects like sending
@@ -837,11 +840,6 @@ public:
       // fork() fails; see bug 227246 and bug 1299581.
       return Error(ECHILD);
 
-#ifdef __NR_arch_prctl
-    case __NR_arch_prctl:
-#endif
-      return Allow();
-
     case __NR_eventfd2:
     case __NR_inotify_init:
     case __NR_inotify_init1:
diff --git a/security/sandbox/linux/reporter/SandboxReporterWrappers.cpp b/security/sandbox/linux/reporter/SandboxReporterWrappers.cpp
index ebe6cc1ec369..cac097fcbd8f 100644
--- a/security/sandbox/linux/reporter/SandboxReporterWrappers.cpp
+++ b/security/sandbox/linux/reporter/SandboxReporterWrappers.cpp
@@ -75,6 +75,9 @@ NS_IMETHODIMP SandboxReportWrapper::GetProcType(nsACString& aProcType)
   case SandboxReport::ProcType::CONTENT:
     aProcType.AssignLiteral("content");
     return NS_OK;
+  case SandboxReport::ProcType::FILE:
+    aProcType.AssignLiteral("file");
+    return NS_OK;
   case SandboxReport::ProcType::MEDIA_PLUGIN:
     aProcType.AssignLiteral("mediaPlugin");
     return NS_OK;
diff --git a/servo/Cargo.lock b/servo/Cargo.lock
index 19ac18f08fdb..889ea6b16168 100644
--- a/servo/Cargo.lock
+++ b/servo/Cargo.lock
@@ -2,7 +2,7 @@
 name = "webvr_traits"
 version = "0.0.1"
 dependencies = [
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "rust-webvr-api 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -149,11 +149,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "bincode"
-version = "0.8.1"
+version = "0.9.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-traits 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -192,6 +191,11 @@ name = "bitflags"
 version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "bitflags"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "bitreader"
 version = "0.3.0"
@@ -209,7 +213,7 @@ dependencies = [
  "bitflags 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bluetooth_traits 0.0.1",
  "device 0.0.1 (git+https://github.com/servo/devices)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_config 0.0.1",
  "servo_rand 0.0.1",
  "tinyfiledialogs 2.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -220,7 +224,7 @@ dependencies = [
 name = "bluetooth_traits"
 version = "0.0.1"
 dependencies = [
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_config 0.0.1",
@@ -308,10 +312,11 @@ dependencies = [
  "euclid 0.15.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "fnv 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "gleam 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
  "offscreen_gl_context 0.11.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo_config 0.0.1",
  "webrender 0.52.1 (git+https://github.com/servo/webrender)",
  "webrender_api 0.52.1 (git+https://github.com/servo/webrender)",
 ]
@@ -324,7 +329,7 @@ dependencies = [
  "euclid 0.15.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize_derive 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "nonzero 0.0.1",
  "offscreen_gl_context 0.11.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -469,7 +474,7 @@ dependencies = [
  "gfx_traits 0.0.1",
  "gleam 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.16.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
@@ -502,7 +507,7 @@ dependencies = [
  "gfx 0.0.1",
  "gfx_traits 0.0.1",
  "hyper 0.10.13 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "itertools 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "layout_traits 0.0.1",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -695,7 +700,7 @@ dependencies = [
  "devtools_traits 0.0.1",
  "hyper 0.10.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper_serde 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "serde 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -712,7 +717,7 @@ dependencies = [
  "heapsize_derive 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.10.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper_serde 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "serde 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_url 0.0.1",
@@ -1095,7 +1100,7 @@ dependencies = [
  "harfbuzz-sys 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize_derive 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1128,7 +1133,7 @@ version = "0.0.1"
 dependencies = [
  "cssparser 0.22.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "gfx 0.0.1",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "style 0.0.1",
 ]
 
@@ -1419,10 +1424,10 @@ dependencies = [
 
 [[package]]
 name = "ipc-channel"
-version = "0.8.0"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bincode 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bincode 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "fnv 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1457,7 +1462,7 @@ dependencies = [
 [[package]]
 name = "js"
 version = "0.1.6"
-source = "git+https://github.com/servo/rust-mozjs#3de4ff3d52361a47a17e3b4fcb02c779b99d93d4"
+source = "git+https://github.com/servo/rust-mozjs#cdb9570900b74cf4e0ba129eeb8bf527cee3ddb5"
 dependencies = [
  "cmake 0.1.22 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1510,7 +1515,7 @@ dependencies = [
  "gfx_traits 0.0.1",
  "heapsize 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "html5ever 0.20.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
@@ -1558,7 +1563,7 @@ dependencies = [
  "gfx_traits 0.0.1",
  "heapsize 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "html5ever 0.20.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "layout 0.0.1",
  "layout_traits 0.0.1",
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1591,7 +1596,7 @@ name = "layout_traits"
 version = "0.0.1"
 dependencies = [
  "gfx 0.0.1",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "metrics 0.0.1",
  "msg 0.0.1",
  "net_traits 0.0.1",
@@ -1665,7 +1670,7 @@ dependencies = [
  "gaol 0.0.1 (git+https://github.com/servo/gaol)",
  "gfx 0.0.1",
  "gleam 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "layout_thread 0.0.1",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
@@ -1795,7 +1800,7 @@ version = "0.0.1"
 dependencies = [
  "gfx 0.0.1",
  "gfx_traits 0.0.1",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "profile_traits 0.0.1",
@@ -1810,7 +1815,7 @@ dependencies = [
  "euclid 0.15.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "gfx 0.0.1",
  "gfx_traits 0.0.1",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "metrics 0.0.1",
  "msg 0.0.1",
  "net_traits 0.0.1",
@@ -1947,7 +1952,7 @@ dependencies = [
  "hyper-openssl 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper_serde 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "immeta 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "matches 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1994,7 +1999,7 @@ dependencies = [
  "hyper 0.10.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper-openssl 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper_serde 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net 0.0.1",
  "net_traits 0.0.1",
@@ -2016,7 +2021,7 @@ dependencies = [
  "hyper 0.10.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper_serde 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.16.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
@@ -2265,11 +2270,6 @@ dependencies = [
  "multistr 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "pdqsort"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "peeking_take_while"
 version = "0.1.2"
@@ -2368,7 +2368,7 @@ version = "0.0.1"
 dependencies = [
  "heartbeats-simple 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "influent 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "profile_traits 0.0.1",
@@ -2384,7 +2384,7 @@ dependencies = [
 name = "profile_tests"
 version = "0.0.1"
 dependencies = [
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "profile 0.0.1",
  "profile_traits 0.0.1",
 ]
@@ -2395,7 +2395,7 @@ version = "0.0.1"
 dependencies = [
  "energy-monitor 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "energymon 0.3.0 (git+https://github.com/energymon/energymon-rust.git)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_config 0.0.1",
@@ -2606,7 +2606,7 @@ dependencies = [
  "hyper 0.10.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper_serde 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.16.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "js 0.1.6 (git+https://github.com/servo/rust-mozjs)",
  "jstraceable_derive 0.0.1",
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2618,6 +2618,7 @@ dependencies = [
  "mitochondria 1.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
+ "nonzero 0.0.1",
  "num-traits 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
  "offscreen_gl_context 0.11.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "open 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2669,7 +2670,7 @@ dependencies = [
  "heapsize 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize_derive 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "html5ever 0.20.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "metrics 0.0.1",
@@ -2716,7 +2717,7 @@ dependencies = [
  "heapsize_derive 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.10.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper_serde 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
@@ -3159,7 +3160,6 @@ dependencies = [
  "ordered-float 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "owning_ref 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "pdqsort 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "precomputed-hash 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3583,7 +3583,7 @@ dependencies = [
  "euclid 0.15.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.10.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.16.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
@@ -3600,11 +3600,11 @@ dependencies = [
 [[package]]
 name = "webrender"
 version = "0.52.1"
-source = "git+https://github.com/servo/webrender#cd4415aa563903f08ecd0602ec97a79879efcaf6"
+source = "git+https://github.com/servo/webrender#5e30fb4168a22440d91066c246eb16e35eb84e91"
 dependencies = [
  "app_units 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "bincode 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "bitflags 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bincode 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-foundation 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-graphics 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3628,18 +3628,18 @@ dependencies = [
 [[package]]
 name = "webrender_api"
 version = "0.52.1"
-source = "git+https://github.com/servo/webrender#cd4415aa563903f08ecd0602ec97a79879efcaf6"
+source = "git+https://github.com/servo/webrender#5e30fb4168a22440d91066c246eb16e35eb84e91"
 dependencies = [
  "app_units 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "bincode 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "bitflags 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bincode 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-foundation 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-graphics 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "dwrote 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.15.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -3650,7 +3650,7 @@ version = "0.0.1"
 dependencies = [
  "canvas_traits 0.0.1",
  "euclid 0.15.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "rust-webvr 0.9.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3778,11 +3778,12 @@ dependencies = [
 "checksum backtrace-sys 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "3a0d842ea781ce92be2bf78a9b38883948542749640b8378b3b2f03d1fd9f1ff"
 "checksum base64 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "96434f987501f0ed4eb336a411e0631ecd1afa11574fe148587adc4ff96143c9"
 "checksum binary-space-partition 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "88ceb0d16c4fd0e42876e298d7d3ce3780dd9ebdcbe4199816a32c77e08597ff"
-"checksum bincode 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "6e4a2d3bab374f96192eade8f41914373d7b5fcf030ca2f45141f1e939057259"
+"checksum bincode 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9a6301db0b49fb63551bc15b5ae348147101cdf323242b93ec7546d5002ff1af"
 "checksum bindgen 0.29.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ba610cba0c1727ed837316540068b51349b8268c073906067b7c3948598929bd"
 "checksum bitflags 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "aad18937a628ec6abcd26d1489012cc0e18c21798210f491af69ded9b881106d"
 "checksum bitflags 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1370e9fc2a6ae53aea8b7a5110edbd08836ed87c88736dfabccade1c2b44bff4"
 "checksum bitflags 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4efd02e230a02e18f92fc2735f44597385ed02ad8f831e7c1c1156ee5e1ab3a5"
+"checksum bitflags 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f5cde24d1b2e2216a726368b2363a273739c91f4e3eb4e0dd12d672d396ad989"
 "checksum bitreader 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "80b13e2ab064ff3aa0bdbf1eff533f9822dc37899821f5f98c67f263eab51707"
 "checksum block 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0d8c1fef690941d3e7788d328517591fecc684c084084702d6ff1641e993699a"
 "checksum blurdroid 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "d7daba519d29beebfc7d302795af88a16b43f431b9b268586926ac61cc655a68"
@@ -3885,7 +3886,7 @@ dependencies = [
 "checksum influent 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a22b311b83431be3ab9af96ca9ea41554bb4a8551ea871ae44c3ce0c57e55f2c"
 "checksum io-surface 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ad4578cee6ed49a17766fa608a4425008313c55ebb7a267622cbddd6b01751e2"
 "checksum iovec 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "29d062ee61fccdf25be172e70f34c9f6efc597e1fb8f6526e8437b2046ab26be"
-"checksum ipc-channel 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a38ad662f104525ac57012e0b79aad07507e3fc11e3bae668bf416264e760ebb"
+"checksum ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c10ed089b1921b01ef342c736a37ee0788eeb9a5f373bb2df1ba88d01125064f"
 "checksum itertools 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4833d6978da405305126af4ac88569b5d71ff758581ce5a987dbfa3755f694fc"
 "checksum itoa 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "eb2f404fbc66fd9aac13e998248505e7ecb2ad8e44ab6388684c5fb11c6c251c"
 "checksum jpeg-decoder 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "2805ccb10ffe4d10e06ef68a158ff94c255211ecbae848fbde2146b098f93ce7"
@@ -3945,7 +3946,6 @@ dependencies = [
 "checksum parking_lot 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "149d8f5b97f3c1133e3cfcd8886449959e856b557ff281e292b733d7c69e005e"
 "checksum parking_lot_core 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "4f610cb9664da38e417ea3225f23051f589851999535290e077939838ab7a595"
 "checksum parse-hosts 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f3842db828281691db6e6f1709ed6a73025747c0cd15cc10346a5cb021e2bc28"
-"checksum pdqsort 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "ceca1642c89148ca05611cc775a0c383abef355fc4907c4e95f49f7b09d6287c"
 "checksum peeking_take_while 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "19b17cddbe7ec3f8bc800887bab5e717348c95ea2ca0b1bf0837fb964dc67099"
 "checksum percent-encoding 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "de154f638187706bde41d9b4738748933d64e6b37bdbffc0b47a97d16a6ae356"
 "checksum phf 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)" = "cb325642290f28ee14d8c6201159949a872f220c62af6e110a56ea914fbe42fc"
diff --git a/servo/components/bluetooth/Cargo.toml b/servo/components/bluetooth/Cargo.toml
index 45a1d381d9ad..5683c7b8150c 100644
--- a/servo/components/bluetooth/Cargo.toml
+++ b/servo/components/bluetooth/Cargo.toml
@@ -13,7 +13,7 @@ path = "lib.rs"
 bitflags = "0.7"
 bluetooth_traits = {path = "../bluetooth_traits"}
 device = {git = "https://github.com/servo/devices", features = ["bluetooth-test"]}
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 servo_config = {path = "../config"}
 servo_rand = {path = "../rand"}
 uuid = {version = "0.5", features = ["v4"]}
diff --git a/servo/components/bluetooth_traits/Cargo.toml b/servo/components/bluetooth_traits/Cargo.toml
index d67faf596fa9..cb4009644cc3 100644
--- a/servo/components/bluetooth_traits/Cargo.toml
+++ b/servo/components/bluetooth_traits/Cargo.toml
@@ -10,7 +10,7 @@ name = "bluetooth_traits"
 path = "lib.rs"
 
 [dependencies]
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 regex = "0.2"
 serde = "1.0"
 servo_config = {path = "../config"}
diff --git a/servo/components/canvas/Cargo.toml b/servo/components/canvas/Cargo.toml
index 00eb302369a3..8c56627bfcb0 100644
--- a/servo/components/canvas/Cargo.toml
+++ b/servo/components/canvas/Cargo.toml
@@ -17,9 +17,10 @@ cssparser = "0.22.0"
 euclid = "0.15"
 fnv = "1.0"
 gleam = "0.4"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 log = "0.3.5"
 num-traits = "0.1.32"
 offscreen_gl_context = { version = "0.11", features = ["serde", "osmesa"] }
+servo_config = {path = "../config"}
 webrender = {git = "https://github.com/servo/webrender"}
 webrender_api = {git = "https://github.com/servo/webrender", features = ["ipc"]}
diff --git a/servo/components/canvas/lib.rs b/servo/components/canvas/lib.rs
index e26d8c2b5826..809a69237c0c 100644
--- a/servo/components/canvas/lib.rs
+++ b/servo/components/canvas/lib.rs
@@ -15,6 +15,7 @@ extern crate ipc_channel;
 #[macro_use] extern crate log;
 extern crate num_traits;
 extern crate offscreen_gl_context;
+extern crate servo_config;
 extern crate webrender;
 extern crate webrender_api;
 
diff --git a/servo/components/canvas/webgl_mode/inprocess.rs b/servo/components/canvas/webgl_mode/inprocess.rs
index 71ab8d8a934d..d8d4b4656f1d 100644
--- a/servo/components/canvas/webgl_mode/inprocess.rs
+++ b/servo/components/canvas/webgl_mode/inprocess.rs
@@ -6,9 +6,12 @@ use ::gl_context::GLContextFactory;
 use ::webgl_thread::{WebGLExternalImageApi, WebGLExternalImageHandler, WebGLThreadObserver, WebGLThread};
 use canvas_traits::webgl::{WebGLChan, WebGLContextId, WebGLMsg, WebGLPipeline, WebGLReceiver};
 use canvas_traits::webgl::{WebGLSender, WebVRCommand, WebVRRenderHandler};
+use canvas_traits::webgl::DOMToTextureCommand;
 use canvas_traits::webgl::webgl_channel;
 use euclid::Size2D;
+use fnv::FnvHashMap;
 use gleam::gl;
+use servo_config::prefs::PREFS;
 use std::marker::PhantomData;
 use std::rc::Rc;
 use webrender;
@@ -23,14 +26,19 @@ impl WebGLThreads {
                webrender_gl: Rc<gl::Gl>,
                webrender_api_sender: webrender_api::RenderApiSender,
                webvr_compositor: Option<Box<WebVRRenderHandler>>)
-               -> (WebGLThreads, Box<webrender::ExternalImageHandler>) {
+               -> (WebGLThreads, Box<webrender::ExternalImageHandler>, Option<Box<webrender::OutputImageHandler>>) {
         // This implementation creates a single `WebGLThread` for all the pipelines.
         let channel = WebGLThread::start(gl_factory,
                                          webrender_api_sender,
                                          webvr_compositor.map(|c| WebVRRenderWrapper(c)),
                                          PhantomData);
+        let output_handler = if PREFS.is_dom_to_texture_enabled() {
+            Some(Box::new(OutputHandler::new(webrender_gl.clone(), channel.clone())))
+        } else {
+            None
+        };
         let external = WebGLExternalImageHandler::new(WebGLExternalImages::new(webrender_gl, channel.clone()));
-        (WebGLThreads(channel), Box::new(external))
+        (WebGLThreads(channel), Box::new(external), output_handler.map(|b| b as Box<_>))
     }
 
     /// Gets the WebGLThread handle for each script pipeline.
@@ -105,3 +113,47 @@ impl WebVRRenderHandler for WebVRRenderWrapper {
         self.0.handle(command, texture);
     }
 }
+
+/// struct used to implement DOMToTexture feature and webrender::OutputImageHandler trait.
+type OutputHandlerData = Option<(u32, Size2D<i32>)>;
+struct OutputHandler {
+    webrender_gl: Rc<gl::Gl>,
+    webgl_channel: WebGLSender<WebGLMsg>,
+    // Used to avoid creating a new channel on each received WebRender request.
+    lock_channel: (WebGLSender<OutputHandlerData>, WebGLReceiver<OutputHandlerData>),
+    sync_objects: FnvHashMap<webrender_api::PipelineId, gl::GLsync>,
+}
+
+impl OutputHandler {
+    fn new(webrender_gl: Rc<gl::Gl>, channel: WebGLSender<WebGLMsg>) -> Self {
+        Self {
+            webrender_gl,
+            webgl_channel: channel,
+            lock_channel: webgl_channel().unwrap(),
+            sync_objects: Default::default(),
+        }
+    }
+}
+
+/// Bridge between the WR frame outputs and WebGL to implement DOMToTexture synchronization.
+impl webrender::OutputImageHandler for OutputHandler {
+    fn lock(&mut self, id: webrender_api::PipelineId) -> Option<(u32, webrender_api::DeviceIntSize)> {
+        // Insert a fence in the WR command queue
+        let gl_sync = self.webrender_gl.fence_sync(gl::SYNC_GPU_COMMANDS_COMPLETE, 0);
+        // The lock command adds a WaitSync call on the WebGL command flow.
+        let command = DOMToTextureCommand::Lock(id, gl_sync as usize, self.lock_channel.0.clone());
+        self.webgl_channel.send(WebGLMsg::DOMToTextureCommand(command)).unwrap();
+        self.lock_channel.1.recv().unwrap().map(|(tex_id, size)| {
+            (tex_id, webrender_api::DeviceIntSize::new(size.width, size.height))
+        })
+    }
+
+    fn unlock(&mut self, id: webrender_api::PipelineId) {
+        if let Some(gl_sync) = self.sync_objects.remove(&id) {
+            // Flush the Sync object into the GPU's command queue to guarantee that it it's signaled.
+            self.webrender_gl.flush();
+            // Mark the sync object for deletion.
+            self.webrender_gl.delete_sync(gl_sync);
+        }
+    }
+}
diff --git a/servo/components/canvas/webgl_thread.rs b/servo/components/canvas/webgl_thread.rs
index 2bb9077954a2..76dfa752ade4 100644
--- a/servo/components/canvas/webgl_thread.rs
+++ b/servo/components/canvas/webgl_thread.rs
@@ -36,6 +36,8 @@ pub struct WebGLThread<VR: WebVRRenderHandler + 'static, OB: WebGLThreadObserver
     webvr_compositor: Option<VR>,
     /// Generic observer that listens WebGLContext creation, resize or removal events.
     observer: OB,
+    /// Texture ids and sizes used in DOM to texture outputs.
+    dom_outputs: FnvHashMap<webrender_api::PipelineId, DOMToTextureData>,
 }
 
 impl<VR: WebVRRenderHandler + 'static, OB: WebGLThreadObserver> WebGLThread<VR, OB> {
@@ -52,6 +54,7 @@ impl<VR: WebVRRenderHandler + 'static, OB: WebGLThreadObserver> WebGLThread<VR,
             next_webgl_id: 0,
             webvr_compositor,
             observer: observer,
+            dom_outputs: Default::default(),
         }
     }
 
@@ -117,6 +120,9 @@ impl<VR: WebVRRenderHandler + 'static, OB: WebGLThreadObserver> WebGLThread<VR,
             WebGLMsg::UpdateWebRenderImage(ctx_id, sender) => {
                 self.handle_update_wr_image(ctx_id, sender);
             },
+            WebGLMsg::DOMToTextureCommand(command) => {
+                self.handle_dom_to_texture(command);
+            },
             WebGLMsg::Exit => {
                 return true;
             }
@@ -323,6 +329,54 @@ impl<VR: WebVRRenderHandler + 'static, OB: WebGLThreadObserver> WebGLThread<VR,
         sender.send(image_key).unwrap();
     }
 
+    fn handle_dom_to_texture(&mut self, command: DOMToTextureCommand) {
+        match command {
+            DOMToTextureCommand::Attach(context_id, texture_id, document_id, pipeline_id, size) => {
+                let ctx = Self::make_current_if_needed(context_id, &self.contexts, &mut self.bound_context_id)
+                                .expect("WebGLContext not found in a WebGL DOMToTextureCommand::Attach command");
+                // Initialize the texture that WR will use for frame outputs.
+                ctx.gl().tex_image_2d(gl::TEXTURE_2D,
+                                      0,
+                                      gl::RGBA as gl::GLint,
+                                      size.width,
+                                      size.height,
+                                      0,
+                                      gl::RGBA,
+                                      gl::UNSIGNED_BYTE,
+                                      None);
+                self.dom_outputs.insert(pipeline_id, DOMToTextureData {
+                    context_id, texture_id, document_id, size
+                });
+                self.webrender_api.enable_frame_output(document_id, pipeline_id, true);
+            },
+            DOMToTextureCommand::Lock(pipeline_id, gl_sync, sender) => {
+                let contexts = &self.contexts;
+                let bound_context_id = &mut self.bound_context_id;
+                let result = self.dom_outputs.get(&pipeline_id).and_then(|data| {
+                    let ctx = Self::make_current_if_needed(data.context_id, contexts, bound_context_id);
+                    ctx.and_then(|ctx| {
+                        // The next glWaitSync call is used to synchronize the two flows of
+                        // OpenGL commands (WR and WebGL) in order to avoid using semi-ready WR textures.
+                        // glWaitSync doesn't block WebGL CPU thread.
+                        ctx.gl().wait_sync(gl_sync as gl::GLsync, 0, gl::TIMEOUT_IGNORED);
+                        Some((data.texture_id.get(), data.size))
+                    })
+                });
+
+                // Send the texture id and size to WR.
+                sender.send(result).unwrap();
+            },
+            DOMToTextureCommand::Detach(texture_id) => {
+                if let Some((pipeline_id, document_id)) = self.dom_outputs.iter()
+                                                                          .find(|&(_, v)| v.texture_id == texture_id)
+                                                                          .map(|(k, v)| (*k, v.document_id)) {
+                    self.webrender_api.enable_frame_output(document_id, pipeline_id, false);
+                    self.dom_outputs.remove(&pipeline_id);
+                }
+            },
+        }
+    }
+
     /// Gets a reference to a GLContextWrapper for a given WebGLContextId and makes it current if required.
     fn make_current_if_needed<'a>(context_id: WebGLContextId,
                                   contexts: &'a FnvHashMap<WebGLContextId, GLContextWrapper>,
@@ -552,6 +606,14 @@ impl<T: WebGLExternalImageApi> webrender::ExternalImageHandler for WebGLExternal
     }
 }
 
+/// Data about the linked DOM<->WebGLTexture elements.
+struct DOMToTextureData {
+    context_id: WebGLContextId,
+    texture_id: WebGLTextureId,
+    document_id: webrender_api::DocumentId,
+    size: Size2D<i32>,
+}
+
 /// WebGL Commands Implementation
 pub struct WebGLImpl;
 
diff --git a/servo/components/canvas_traits/Cargo.toml b/servo/components/canvas_traits/Cargo.toml
index 8c5143125112..54db398a6815 100644
--- a/servo/components/canvas_traits/Cargo.toml
+++ b/servo/components/canvas_traits/Cargo.toml
@@ -14,7 +14,7 @@ cssparser = "0.22.0"
 euclid = "0.15"
 heapsize = "0.4"
 heapsize_derive = "0.1"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 lazy_static = "0.2"
 nonzero = {path = "../nonzero"}
 offscreen_gl_context = { version = "0.11", features = ["serde"] }
diff --git a/servo/components/canvas_traits/webgl.rs b/servo/components/canvas_traits/webgl.rs
index 98c4115c69ce..9d53e93287f2 100644
--- a/servo/components/canvas_traits/webgl.rs
+++ b/servo/components/canvas_traits/webgl.rs
@@ -3,10 +3,10 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use euclid::Size2D;
-use nonzero::NonZeroU32;
+use nonzero::NonZero;
 use offscreen_gl_context::{GLContextAttributes, GLLimits};
 use std::fmt;
-use webrender_api;
+use webrender_api::{DocumentId, ImageKey, PipelineId};
 
 /// Sender type used in WebGLCommands.
 pub use ::webgl_channel::WebGLSender;
@@ -46,7 +46,9 @@ pub enum WebGLMsg {
     /// Unlock messages are always sent after a Lock message.
     Unlock(WebGLContextId),
     /// Creates or updates the image keys required for WebRender.
-    UpdateWebRenderImage(WebGLContextId, WebGLSender<webrender_api::ImageKey>),
+    UpdateWebRenderImage(WebGLContextId, WebGLSender<ImageKey>),
+    /// Commands used for the DOMToTexture feature.
+    DOMToTextureCommand(DOMToTextureCommand),
     /// Frees all resources and closes the thread.
     Exit,
 }
@@ -86,6 +88,11 @@ impl WebGLMsgSender {
         }
     }
 
+    /// Returns the WebGLContextId associated to this sender
+    pub fn context_id(&self) -> WebGLContextId {
+        self.ctx_id
+    }
+
     /// Send a WebGLCommand message
     #[inline]
     pub fn send(&self, command: WebGLCommand) -> WebGLSendResult {
@@ -113,9 +120,13 @@ impl WebGLMsgSender {
     }
 
     #[inline]
-    pub fn send_update_wr_image(&self, sender: WebGLSender<webrender_api::ImageKey>) -> WebGLSendResult {
+    pub fn send_update_wr_image(&self, sender: WebGLSender<ImageKey>) -> WebGLSendResult {
         self.sender.send(WebGLMsg::UpdateWebRenderImage(self.ctx_id, sender))
     }
+
+    pub fn send_dom_to_texture(&self, command: DOMToTextureCommand) -> WebGLSendResult {
+        self.sender.send(WebGLMsg::DOMToTextureCommand(command))
+    }
 }
 
 /// WebGL Commands for a specific WebGLContext
@@ -242,13 +253,13 @@ pub enum WebGLCommand {
 macro_rules! define_resource_id_struct {
     ($name:ident) => {
         #[derive(Clone, Copy, Eq, Hash, PartialEq)]
-        pub struct $name(NonZeroU32);
+        pub struct $name(NonZero<u32>);
 
         impl $name {
             #[allow(unsafe_code)]
             #[inline]
             pub unsafe fn new(id: u32) -> Self {
-                $name(NonZeroU32::new_unchecked(id))
+                $name(NonZero::new_unchecked(id))
             }
 
             #[inline]
@@ -379,6 +390,17 @@ pub trait WebVRRenderHandler: Send {
     fn handle(&mut self, command: WebVRCommand, texture: Option<(u32, Size2D<i32>)>);
 }
 
+/// WebGL commands required to implement DOMToTexture feature.
+#[derive(Clone, Deserialize, Serialize)]
+pub enum DOMToTextureCommand {
+    /// Attaches a HTMLIFrameElement to a WebGLTexture.
+    Attach(WebGLContextId, WebGLTextureId, DocumentId, PipelineId, Size2D<i32>),
+    /// Releases the HTMLIFrameElement to WebGLTexture attachment.
+    Detach(WebGLTextureId),
+    /// Lock message used for a correct synchronization with WebRender GL flow.
+    Lock(PipelineId, usize, WebGLSender<Option<(u32, Size2D<i32>)>>),
+}
+
 impl fmt::Debug for WebGLCommand {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         use self::WebGLCommand::*;
diff --git a/servo/components/compositing/Cargo.toml b/servo/components/compositing/Cargo.toml
index e8ed7c5d4974..40ec91054486 100644
--- a/servo/components/compositing/Cargo.toml
+++ b/servo/components/compositing/Cargo.toml
@@ -14,7 +14,7 @@ euclid = "0.15"
 gfx_traits = {path = "../gfx_traits"}
 gleam = "0.4"
 image = "0.16"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 log = "0.3.5"
 msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
diff --git a/servo/components/compositing/compositor.rs b/servo/components/compositing/compositor.rs
index 7e77157b8456..a652346c7943 100644
--- a/servo/components/compositing/compositor.rs
+++ b/servo/components/compositing/compositor.rs
@@ -13,7 +13,7 @@ use image::{DynamicImage, ImageFormat, RgbImage};
 use ipc_channel::ipc::{self, IpcSharedMemory};
 use msg::constellation_msg::{PipelineId, PipelineIndex, PipelineNamespaceId};
 use net_traits::image::base::{Image, PixelFormat};
-use nonzero::NonZeroU32;
+use nonzero::NonZero;
 use profile_traits::time::{self, ProfilerCategory, profile};
 use script_traits::{AnimationState, AnimationTickType, ConstellationControlMsg};
 use script_traits::{ConstellationMsg, LayoutControlMsg, MouseButton};
@@ -62,7 +62,7 @@ impl ConvertPipelineIdFromWebRender for webrender_api::PipelineId {
     fn from_webrender(&self) -> PipelineId {
         PipelineId {
             namespace_id: PipelineNamespaceId(self.0),
-            index: PipelineIndex(NonZeroU32::new(self.1).expect("Webrender pipeline zero?")),
+            index: PipelineIndex(NonZero::new(self.1).expect("Webrender pipeline zero?")),
         }
     }
 }
@@ -1502,9 +1502,9 @@ impl<Window: WindowMethods> IOCompositor<Window> {
     pub fn toggle_webrender_debug(&mut self, option: WebRenderDebugOption) {
         let mut flags = self.webrender.get_debug_flags();
         let flag = match option {
-            WebRenderDebugOption::Profiler => webrender::PROFILER_DBG,
-            WebRenderDebugOption::TextureCacheDebug => webrender::TEXTURE_CACHE_DBG,
-            WebRenderDebugOption::RenderTargetDebug => webrender::RENDER_TARGET_DBG,
+            WebRenderDebugOption::Profiler => webrender::DebugFlags::PROFILER_DBG,
+            WebRenderDebugOption::TextureCacheDebug => webrender::DebugFlags::TEXTURE_CACHE_DBG,
+            WebRenderDebugOption::RenderTargetDebug => webrender::DebugFlags::RENDER_TARGET_DBG,
         };
         flags.toggle(flag);
         self.webrender.set_debug_flags(flags);
diff --git a/servo/components/config/prefs.rs b/servo/components/config/prefs.rs
index 3bfb94772b1e..397b060cc031 100644
--- a/servo/components/config/prefs.rs
+++ b/servo/components/config/prefs.rs
@@ -273,4 +273,8 @@ impl Preferences {
     pub fn is_webvr_enabled(&self) -> bool {
         self.get("dom.webvr.enabled").as_boolean().unwrap_or(false)
     }
+
+    pub fn is_dom_to_texture_enabled(&self) -> bool {
+        self.get("dom.webgl.dom_to_texture.enabled").as_boolean().unwrap_or(false)
+    }
 }
diff --git a/servo/components/constellation/Cargo.toml b/servo/components/constellation/Cargo.toml
index 2d659bd4342b..0e48b302dc55 100644
--- a/servo/components/constellation/Cargo.toml
+++ b/servo/components/constellation/Cargo.toml
@@ -22,7 +22,7 @@ euclid = "0.15"
 gfx = {path = "../gfx"}
 gfx_traits = {path = "../gfx_traits"}
 hyper = "0.10"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 itertools = "0.5"
 layout_traits = {path = "../layout_traits"}
 log = "0.3.5"
diff --git a/servo/components/constellation/pipeline.rs b/servo/components/constellation/pipeline.rs
index 57cf07d07d88..d5a41df44600 100644
--- a/servo/components/constellation/pipeline.rs
+++ b/servo/components/constellation/pipeline.rs
@@ -511,6 +511,7 @@ impl UnprivilegedPipelineContent {
             content_process_shutdown_chan: self.script_content_process_shutdown_chan,
             webgl_chan: self.webgl_chan,
             webvr_chan: self.webvr_chan,
+            webrender_document: self.webrender_document,
         }, self.load_data.clone());
 
         LTF::create(self.id,
diff --git a/servo/components/devtools/Cargo.toml b/servo/components/devtools/Cargo.toml
index 2ce43e5eb1f6..f5d149f4099b 100644
--- a/servo/components/devtools/Cargo.toml
+++ b/servo/components/devtools/Cargo.toml
@@ -13,7 +13,7 @@ path = "lib.rs"
 devtools_traits = {path = "../devtools_traits"}
 hyper = "0.10"
 hyper_serde = "0.7"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 log = "0.3.5"
 msg = {path = "../msg"}
 serde = "1.0"
diff --git a/servo/components/devtools_traits/Cargo.toml b/servo/components/devtools_traits/Cargo.toml
index fe0cc20c674b..323cd25f946d 100644
--- a/servo/components/devtools_traits/Cargo.toml
+++ b/servo/components/devtools_traits/Cargo.toml
@@ -15,7 +15,7 @@ heapsize = "0.4"
 heapsize_derive = "0.1"
 hyper = "0.10"
 hyper_serde = "0.7"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 msg = {path = "../msg"}
 serde = "1.0"
 servo_url = {path = "../url"}
diff --git a/servo/components/gfx/Cargo.toml b/servo/components/gfx/Cargo.toml
index c8ee2d496296..405d9db5646a 100644
--- a/servo/components/gfx/Cargo.toml
+++ b/servo/components/gfx/Cargo.toml
@@ -23,7 +23,7 @@ gfx_traits = {path = "../gfx_traits"}
 harfbuzz-sys = "0.1"
 heapsize = "0.4"
 heapsize_derive = "0.1"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 lazy_static = "0.2"
 libc = "0.2"
 log = "0.3.5"
diff --git a/servo/components/gfx/display_list/mod.rs b/servo/components/gfx/display_list/mod.rs
index e0284b738057..341024b63eed 100644
--- a/servo/components/gfx/display_list/mod.rs
+++ b/servo/components/gfx/display_list/mod.rs
@@ -606,7 +606,7 @@ pub enum DisplayItem {
     Line(Box<LineDisplayItem>),
     BoxShadow(Box<BoxShadowDisplayItem>),
     PushTextShadow(Box<PushTextShadowDisplayItem>),
-    PopTextShadow(Box<PopTextShadowDisplayItem>),
+    PopAllTextShadows(Box<PopAllTextShadowsDisplayItem>),
     Iframe(Box<IframeDisplayItem>),
     PushStackingContext(Box<PushStackingContextItem>),
     PopStackingContext(Box<PopStackingContextItem>),
@@ -1190,7 +1190,7 @@ pub struct PushTextShadowDisplayItem {
 
 /// Defines a text shadow that affects all items until the next PopTextShadow.
 #[derive(Clone, Deserialize, HeapSizeOf, Serialize)]
-pub struct PopTextShadowDisplayItem {
+pub struct PopAllTextShadowsDisplayItem {
     /// Fields common to all display items.
     pub base: BaseDisplayItem,
 }
@@ -1248,7 +1248,7 @@ impl DisplayItem {
             DisplayItem::Line(ref line) => &line.base,
             DisplayItem::BoxShadow(ref box_shadow) => &box_shadow.base,
             DisplayItem::PushTextShadow(ref push_text_shadow) => &push_text_shadow.base,
-            DisplayItem::PopTextShadow(ref pop_text_shadow) => &pop_text_shadow.base,
+            DisplayItem::PopAllTextShadows(ref pop_text_shadow) => &pop_text_shadow.base,
             DisplayItem::Iframe(ref iframe) => &iframe.base,
             DisplayItem::PushStackingContext(ref stacking_context) => &stacking_context.base,
             DisplayItem::PopStackingContext(ref item) => &item.base,
@@ -1373,7 +1373,7 @@ impl fmt::Debug for DisplayItem {
                 DisplayItem::Line(_) => "Line".to_owned(),
                 DisplayItem::BoxShadow(_) => "BoxShadow".to_owned(),
                 DisplayItem::PushTextShadow(_) => "PushTextShadow".to_owned(),
-                DisplayItem::PopTextShadow(_) => "PopTextShadow".to_owned(),
+                DisplayItem::PopAllTextShadows(_) => "PopTextShadow".to_owned(),
                 DisplayItem::Iframe(_) => "Iframe".to_owned(),
                 DisplayItem::PushStackingContext(_) |
                 DisplayItem::PopStackingContext(_) |
diff --git a/servo/components/layout/Cargo.toml b/servo/components/layout/Cargo.toml
index 273a1446a75f..2becf6a56756 100644
--- a/servo/components/layout/Cargo.toml
+++ b/servo/components/layout/Cargo.toml
@@ -20,7 +20,7 @@ gfx = {path = "../gfx"}
 gfx_traits = {path = "../gfx_traits"}
 heapsize = "0.4"
 html5ever = "0.20.0"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 libc = "0.2"
 log = "0.3.5"
 msg = {path = "../msg"}
diff --git a/servo/components/layout/display_list_builder.rs b/servo/components/layout/display_list_builder.rs
index 522766b5f6d0..f29a1f377aef 100644
--- a/servo/components/layout/display_list_builder.rs
+++ b/servo/components/layout/display_list_builder.rs
@@ -28,7 +28,7 @@ use gfx::display_list::{BorderRadii, BoxShadowClipMode, BoxShadowDisplayItem, Cl
 use gfx::display_list::{ClipScrollNodeType, ClippingRegion, DisplayItem, DisplayItemMetadata};
 use gfx::display_list::{DisplayList, DisplayListSection, GradientDisplayItem, IframeDisplayItem};
 use gfx::display_list::{ImageBorder, ImageDisplayItem, LineDisplayItem, NormalBorder, OpaqueNode};
-use gfx::display_list::{PopTextShadowDisplayItem, PushTextShadowDisplayItem};
+use gfx::display_list::{PopAllTextShadowsDisplayItem, PushTextShadowDisplayItem};
 use gfx::display_list::{RadialGradientDisplayItem, SolidColorDisplayItem, StackingContext};
 use gfx::display_list::{StackingContextType, TextDisplayItem, TextOrientation, WebRenderImageInfo};
 use gfx_traits::{combine_id_with_fragment_type, FragmentType, StackingContextId};
@@ -2340,9 +2340,9 @@ impl FragmentDisplayListBuilding for Fragment {
             );
         }
 
-        // Pair all the PushTextShadows
-        for _ in text_shadows {
-            state.add_display_item(DisplayItem::PopTextShadow(Box::new(PopTextShadowDisplayItem {
+        // Pop all the PushTextShadows
+        if !text_shadows.is_empty() {
+            state.add_display_item(DisplayItem::PopAllTextShadows(Box::new(PopAllTextShadowsDisplayItem {
                 base: base.clone(),
             })));
         }
diff --git a/servo/components/layout/webrender_helpers.rs b/servo/components/layout/webrender_helpers.rs
index 8f86477e9806..fbd5d423ddf4 100644
--- a/servo/components/layout/webrender_helpers.rs
+++ b/servo/components/layout/webrender_helpers.rs
@@ -465,8 +465,8 @@ impl WebRenderDisplayItemConverter for DisplayItem {
                                         color: item.color,
                                     });
             }
-            DisplayItem::PopTextShadow(_) => {
-                builder.pop_shadow();
+            DisplayItem::PopAllTextShadows(_) => {
+                builder.pop_all_shadows();
             }
             DisplayItem::Iframe(ref item) => {
                 let rect = item.base.bounds;
diff --git a/servo/components/layout_thread/Cargo.toml b/servo/components/layout_thread/Cargo.toml
index 5bb340f893a2..4106e86e47ce 100644
--- a/servo/components/layout_thread/Cargo.toml
+++ b/servo/components/layout_thread/Cargo.toml
@@ -21,7 +21,7 @@ gfx = {path = "../gfx"}
 gfx_traits = {path = "../gfx_traits"}
 heapsize = "0.4"
 html5ever = "0.20.0"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 layout = {path = "../layout"}
 layout_traits = {path = "../layout_traits"}
 lazy_static = "0.2"
diff --git a/servo/components/layout_thread/dom_wrapper.rs b/servo/components/layout_thread/dom_wrapper.rs
index 2863d840ce5d..08d628a6d6ce 100644
--- a/servo/components/layout_thread/dom_wrapper.rs
+++ b/servo/components/layout_thread/dom_wrapper.rs
@@ -36,7 +36,7 @@ use html5ever::{LocalName, Namespace};
 use layout::data::StyleAndLayoutData;
 use layout::wrapper::GetRawData;
 use msg::constellation_msg::{BrowsingContextId, PipelineId};
-use nonzero::NonZeroUsize;
+use nonzero::NonZero;
 use range::Range;
 use script::layout_exports::{CAN_BE_FRAGMENTED, HAS_DIRTY_DESCENDANTS, IS_IN_DOC};
 use script::layout_exports::{CharacterDataTypeId, ElementTypeId, HTMLElementTypeId, NodeTypeId};
@@ -235,8 +235,7 @@ impl<'ln> LayoutNode for ServoLayoutNode<'ln> {
             let ptr: *mut StyleAndLayoutData =
                 Box::into_raw(Box::new(StyleAndLayoutData::new()));
             let opaque = OpaqueStyleAndLayoutData {
-                ptr: NonZeroUsize::new_unchecked(ptr as usize),
-                phantom: PhantomData,
+                ptr: NonZero::new_unchecked(ptr as *mut StyleData),
             };
             self.init_style_and_layout_data(opaque);
         };
diff --git a/servo/components/layout_traits/Cargo.toml b/servo/components/layout_traits/Cargo.toml
index 6a6824463d42..872125c0d1b3 100644
--- a/servo/components/layout_traits/Cargo.toml
+++ b/servo/components/layout_traits/Cargo.toml
@@ -11,7 +11,7 @@ path = "lib.rs"
 
 [dependencies]
 gfx = {path = "../gfx"}
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 metrics = {path = "../metrics"}
 msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
diff --git a/servo/components/metrics/Cargo.toml b/servo/components/metrics/Cargo.toml
index 96ce4108d32a..2420d240da21 100644
--- a/servo/components/metrics/Cargo.toml
+++ b/servo/components/metrics/Cargo.toml
@@ -12,7 +12,7 @@ path = "lib.rs"
 [dependencies]
 gfx = {path = "../gfx"}
 gfx_traits = {path = "../gfx_traits"}
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 log = "0.3.5"
 msg = {path = "../msg"}
 profile_traits = {path = "../profile_traits"}
diff --git a/servo/components/msg/constellation_msg.rs b/servo/components/msg/constellation_msg.rs
index da9bb3ea0cb6..40c1827b262a 100644
--- a/servo/components/msg/constellation_msg.rs
+++ b/servo/components/msg/constellation_msg.rs
@@ -5,7 +5,7 @@
 //! The high-level interface from script to constellation. Using this abstract interface helps
 //! reduce coupling between these two components.
 
-use nonzero::NonZeroU32;
+use nonzero::NonZero;
 use std::cell::Cell;
 use std::fmt;
 use webrender_api;
@@ -195,9 +195,9 @@ impl PipelineNamespace {
         });
     }
 
-    fn next_index(&mut self) -> NonZeroU32 {
+    fn next_index(&mut self) -> NonZero<u32> {
         self.index += 1;
-        NonZeroU32::new(self.index).expect("pipeline id index wrapped!")
+        NonZero::new(self.index).expect("pipeline id index wrapped!")
     }
 
     fn next_pipeline_id(&mut self) -> PipelineId {
@@ -221,7 +221,7 @@ thread_local!(pub static PIPELINE_NAMESPACE: Cell<Option<PipelineNamespace>> = C
 pub struct PipelineNamespaceId(pub u32);
 
 #[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd, Serialize)]
-pub struct PipelineIndex(pub NonZeroU32);
+pub struct PipelineIndex(pub NonZero<u32>);
 known_heap_size!(0, PipelineIndex);
 
 #[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, HeapSizeOf, Ord, PartialEq, PartialOrd, Serialize)]
@@ -264,7 +264,7 @@ impl fmt::Display for PipelineId {
 }
 
 #[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd, Serialize)]
-pub struct BrowsingContextIndex(pub NonZeroU32);
+pub struct BrowsingContextIndex(pub NonZero<u32>);
 known_heap_size!(0, BrowsingContextIndex);
 
 #[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, HeapSizeOf, Ord, PartialEq, PartialOrd, Serialize)]
@@ -340,13 +340,13 @@ impl PartialEq<BrowsingContextId> for TopLevelBrowsingContextId {
 pub const TEST_NAMESPACE: PipelineNamespaceId = PipelineNamespaceId(1234);
 #[allow(unsafe_code)]
 #[cfg(feature = "unstable")]
-pub const TEST_PIPELINE_INDEX: PipelineIndex = unsafe { PipelineIndex(NonZeroU32::new_unchecked(5678)) };
+pub const TEST_PIPELINE_INDEX: PipelineIndex = unsafe { PipelineIndex(NonZero::new_unchecked(5678)) };
 #[cfg(feature = "unstable")]
 pub const TEST_PIPELINE_ID: PipelineId = PipelineId { namespace_id: TEST_NAMESPACE, index: TEST_PIPELINE_INDEX };
 #[allow(unsafe_code)]
 #[cfg(feature = "unstable")]
 pub const TEST_BROWSING_CONTEXT_INDEX: BrowsingContextIndex =
-    unsafe { BrowsingContextIndex(NonZeroU32::new_unchecked(8765)) };
+    unsafe { BrowsingContextIndex(NonZero::new_unchecked(8765)) };
 #[cfg(feature = "unstable")]
 pub const TEST_BROWSING_CONTEXT_ID: BrowsingContextId =
     BrowsingContextId { namespace_id: TEST_NAMESPACE, index: TEST_BROWSING_CONTEXT_INDEX };
diff --git a/servo/components/net/Cargo.toml b/servo/components/net/Cargo.toml
index ef6dbe2a0303..79e4eaa47783 100644
--- a/servo/components/net/Cargo.toml
+++ b/servo/components/net/Cargo.toml
@@ -19,7 +19,7 @@ hyper = "0.10"
 hyper_serde = "0.7"
 hyper-openssl = "0.2.2"
 immeta = "0.3.1"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 lazy_static = "0.2"
 log = "0.3.5"
 matches = "0.1"
diff --git a/servo/components/net_traits/Cargo.toml b/servo/components/net_traits/Cargo.toml
index 198e9ac9a857..ccc080e58631 100644
--- a/servo/components/net_traits/Cargo.toml
+++ b/servo/components/net_traits/Cargo.toml
@@ -16,7 +16,7 @@ heapsize_derive = "0.1"
 hyper = "0.10"
 hyper_serde = "0.7"
 image = "0.16"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 lazy_static = "0.2"
 log = "0.3.5"
 msg = {path = "../msg"}
diff --git a/servo/components/nonzero/lib.rs b/servo/components/nonzero/lib.rs
index 6682740f34ed..b44cf73c7d6e 100644
--- a/servo/components/nonzero/lib.rs
+++ b/servo/components/nonzero/lib.rs
@@ -9,7 +9,7 @@
 #![cfg_attr(feature = "unstable", feature(const_fn))]
 #![cfg_attr(feature = "unstable", feature(const_nonzero_new))]
 
-#[macro_use]
+#[cfg_attr(not(feature = "unstable"), macro_use)]
 extern crate serde;
 
 pub use imp::*;
@@ -17,105 +17,125 @@ pub use imp::*;
 #[cfg(feature = "unstable")]
 mod imp {
     extern crate core;
-    use self::core::nonzero::NonZero;
+    use self::core::nonzero::NonZero as CoreNonZero;
+    use serde::{Serialize, Serializer, Deserialize, Deserializer};
 
-    #[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd, Serialize)]
-    pub struct NonZeroU32(NonZero<u32>);
+    pub use self::core::nonzero::Zeroable;
 
-    #[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd, Serialize)]
-    pub struct NonZeroUsize(NonZero<usize>);
+    #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+    pub struct NonZero<T: Zeroable>(CoreNonZero<T>);
 
-    impl NonZeroU32 {
-        #[inline] pub const unsafe fn new_unchecked(x: u32) -> Self { NonZeroU32(NonZero::new_unchecked(x)) }
-        #[inline] pub fn new(x: u32) -> Option<Self> { NonZero::new(x).map(NonZeroU32) }
-        #[inline] pub fn get(self) -> u32 { self.0.get() }
+    impl<T: Zeroable> NonZero<T> {
+        #[inline]
+        pub const unsafe fn new_unchecked(x: T) -> Self {
+            NonZero(CoreNonZero::new_unchecked(x))
+        }
+
+        #[inline]
+        pub fn new(x: T) -> Option<Self> {
+            CoreNonZero::new(x).map(NonZero)
+        }
+
+        #[inline]
+        pub fn get(self) -> T {
+            self.0.get()
+        }
     }
 
-    impl NonZeroUsize {
-        #[inline] pub const unsafe fn new_unchecked(x: usize) -> Self { NonZeroUsize(NonZero::new_unchecked(x)) }
-        #[inline] pub fn new(x: usize) -> Option<Self> { NonZero::new(x).map(NonZeroUsize) }
-        #[inline] pub fn get(self) -> usize { self.0.get() }
+    // Not using derive because of the additional Clone bound required by the inner impl
+
+    impl<T> Serialize for NonZero<T>
+    where
+        T: Serialize + Zeroable + Clone,
+    {
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where
+            S: Serializer,
+        {
+            self.0.serialize(serializer)
+        }
+    }
+
+    impl<'de, T> Deserialize<'de> for NonZero<T>
+    where
+        T: Deserialize<'de> + Zeroable,
+    {
+        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        where
+            D: Deserializer<'de>,
+        {
+            CoreNonZero::deserialize(deserializer).map(NonZero)
+        }
     }
 }
 
 #[cfg(not(feature = "unstable"))]
 mod imp {
-    use std::cmp;
-    use std::hash;
-
     #[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd, Serialize)]
-    pub struct NonZeroU32(u32);
+    pub struct NonZero<T: Zeroable>(T);
 
-    impl NonZeroU32 {
+    impl<T: Zeroable> NonZero<T> {
         #[inline]
-        pub fn new(x: u32) -> Option<Self> {
-            if x != 0 {
-                Some(NonZeroU32(x))
-            } else {
+        pub unsafe fn new_unchecked(x: T) -> Self {
+            NonZero(x)
+        }
+
+        #[inline]
+        pub fn new(x: T) -> Option<Self> {
+            if x.is_zero() {
                 None
+            } else {
+                Some(NonZero(x))
             }
         }
 
         #[inline]
-        pub unsafe fn new_unchecked(x: u32) -> Self {
-            NonZeroU32(x)
-        }
-
-        #[inline]
-        pub fn get(self) -> u32 {
+        pub fn get(self) -> T {
             self.0
         }
     }
 
-    #[derive(Clone, Copy, Debug, Eq)]
-    pub struct NonZeroUsize(&'static ());
+    /// Unsafe trait to indicate what types are usable with the NonZero struct
+    pub unsafe trait Zeroable {
+        /// Whether this value is zero
+        fn is_zero(&self) -> bool;
+    }
 
-    impl NonZeroUsize {
-        #[inline]
-        pub fn new(x: usize) -> Option<Self> {
-            if x != 0 {
-                Some(unsafe { Self::new_unchecked(x) })
-            } else {
-                None
-            }
-        }
-
-        #[inline]
-        pub unsafe fn new_unchecked(x: usize) -> Self {
-            NonZeroUsize(&*(x as *const ()))
-        }
-
-        #[inline]
-        pub fn get(self) -> usize {
-            self.0 as *const () as usize
+    macro_rules! impl_zeroable_for_pointer_types {
+        ( $( $Ptr: ty )+ ) => {
+            $(
+                /// For fat pointers to be considered "zero", only the "data" part needs to be null.
+                unsafe impl<T: ?Sized> Zeroable for $Ptr {
+                    #[inline]
+                    fn is_zero(&self) -> bool {
+                        // Cast because `is_null` is only available on thin pointers
+                        (*self as *mut u8).is_null()
+                    }
+                }
+            )+
         }
     }
 
-    impl PartialEq for NonZeroUsize {
-        #[inline]
-        fn eq(&self, other: &Self) -> bool {
-            self.get() == other.get()
+    macro_rules! impl_zeroable_for_integer_types {
+        ( $( $Int: ty )+ ) => {
+            $(
+                unsafe impl Zeroable for $Int {
+                    #[inline]
+                    fn is_zero(&self) -> bool {
+                        *self == 0
+                    }
+                }
+            )+
         }
     }
 
-    impl PartialOrd for NonZeroUsize {
-        #[inline]
-        fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
-            self.get().partial_cmp(&other.get())
-        }
+    impl_zeroable_for_pointer_types! {
+        *const T
+        *mut T
     }
 
-    impl Ord for NonZeroUsize {
-        #[inline]
-        fn cmp(&self, other: &Self) -> cmp::Ordering {
-            self.get().cmp(&other.get())
-        }
-    }
-
-    impl hash::Hash for NonZeroUsize {
-        #[inline]
-        fn hash<H: hash::Hasher>(&self, hasher: &mut H) {
-            self.get().hash(hasher)
-        }
+    impl_zeroable_for_integer_types! {
+        usize u8 u16 u32 u64
+        isize i8 i16 i32 i64
     }
 }
diff --git a/servo/components/profile/Cargo.toml b/servo/components/profile/Cargo.toml
index a02914db61d1..d00c0f5000dc 100644
--- a/servo/components/profile/Cargo.toml
+++ b/servo/components/profile/Cargo.toml
@@ -15,7 +15,7 @@ unstable = []
 [dependencies]
 profile_traits = {path = "../profile_traits"}
 influent = "0.4"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 heartbeats-simple = "0.4"
 log = "0.3.5"
 serde = "1.0"
diff --git a/servo/components/profile_traits/Cargo.toml b/servo/components/profile_traits/Cargo.toml
index 67af6697aeae..1f6680865672 100644
--- a/servo/components/profile_traits/Cargo.toml
+++ b/servo/components/profile_traits/Cargo.toml
@@ -15,7 +15,7 @@ energy-profiling = ["energymon", "energy-monitor"]
 [dependencies]
 energy-monitor = {version = "0.2.0", optional = true}
 energymon = {git = "https://github.com/energymon/energymon-rust.git", optional = true}
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 log = "0.3.5"
 serde = "1.0"
 servo_config = {path = "../config"}
diff --git a/servo/components/remutex/lib.rs b/servo/components/remutex/lib.rs
index 2589a6d11626..5fbbad40bf02 100644
--- a/servo/components/remutex/lib.rs
+++ b/servo/components/remutex/lib.rs
@@ -14,7 +14,7 @@ extern crate nonzero;
 #[macro_use] extern crate lazy_static;
 #[macro_use] extern crate log;
 
-use nonzero::NonZeroUsize;
+use nonzero::NonZero;
 use std::cell::{Cell, UnsafeCell};
 use std::ops::Deref;
 use std::sync::{LockResult, Mutex, MutexGuard, PoisonError, TryLockError, TryLockResult};
@@ -25,7 +25,7 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 // TODO: can we use the thread-id crate for this?
 
 #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
-pub struct ThreadId(NonZeroUsize);
+pub struct ThreadId(NonZero<usize>);
 
 lazy_static!{ static ref THREAD_COUNT: AtomicUsize = AtomicUsize::new(1); }
 
@@ -33,7 +33,7 @@ impl ThreadId {
     #[allow(unsafe_code)]
     fn new() -> ThreadId {
         let number = THREAD_COUNT.fetch_add(1, Ordering::SeqCst);
-        ThreadId(NonZeroUsize::new(number).unwrap())
+        ThreadId(NonZero::new(number).unwrap())
     }
     pub fn current() -> ThreadId {
         THREAD_ID.with(|tls| tls.clone())
@@ -57,13 +57,13 @@ impl AtomicOptThreadId {
     #[allow(unsafe_code)]
     pub fn load(&self, ordering: Ordering) -> Option<ThreadId> {
         let number = self.0.load(ordering);
-        NonZeroUsize::new(number).map(ThreadId)
+        NonZero::new(number).map(ThreadId)
     }
     #[allow(unsafe_code)]
     pub fn swap(&self, value: Option<ThreadId>, ordering: Ordering) -> Option<ThreadId> {
         let number = value.map(|id| id.0.get()).unwrap_or(0);
         let number = self.0.swap(number, ordering);
-        NonZeroUsize::new(number).map(ThreadId)
+        NonZero::new(number).map(ThreadId)
     }
 }
 
diff --git a/servo/components/script/Cargo.toml b/servo/components/script/Cargo.toml
index 6ae95d2fda04..7e0c4068cec1 100644
--- a/servo/components/script/Cargo.toml
+++ b/servo/components/script/Cargo.toml
@@ -13,6 +13,7 @@ path = "lib.rs"
 
 [features]
 debugmozjs = ['js/debugmozjs']
+unstable = []
 
 [build-dependencies]
 cmake = "0.1"
@@ -49,7 +50,7 @@ html5ever = {version = "0.20", features = ["heap_size"]}
 hyper = "0.10"
 hyper_serde = "0.7"
 image = "0.16"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 js = {git = "https://github.com/servo/rust-mozjs", features = ["promises"]}
 jstraceable_derive = {path = "../jstraceable_derive"}
 lazy_static = "0.2"
@@ -61,6 +62,7 @@ mime = "0.2.1"
 mime_guess = "1.8.0"
 msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
+nonzero = {path = "../nonzero"}
 num-traits = "0.1.32"
 offscreen_gl_context = { version = "0.11", features = ["serde"] }
 open = "1.1.1"
diff --git a/servo/components/script/dom/abstractworkerglobalscope.rs b/servo/components/script/dom/abstractworkerglobalscope.rs
index 020301ad8a15..f6d868765edd 100644
--- a/servo/components/script/dom/abstractworkerglobalscope.rs
+++ b/servo/components/script/dom/abstractworkerglobalscope.rs
@@ -24,10 +24,10 @@ impl<T: JSTraceable + DomObject + 'static> ScriptChan for SendableWorkerScriptCh
     }
 
     fn clone(&self) -> Box<ScriptChan + Send> {
-        box SendableWorkerScriptChan {
+        Box::new(SendableWorkerScriptChan {
             sender: self.sender.clone(),
             worker: self.worker.clone(),
-        }
+        })
     }
 }
 
@@ -48,10 +48,10 @@ impl<T: JSTraceable + DomObject + 'static> ScriptChan for WorkerThreadWorkerChan
     }
 
     fn clone(&self) -> Box<ScriptChan + Send> {
-        box WorkerThreadWorkerChan {
+        Box::new(WorkerThreadWorkerChan {
             sender: self.sender.clone(),
             worker: self.worker.clone(),
-        }
+        })
     }
 }
 
diff --git a/servo/components/script/dom/attr.rs b/servo/components/script/dom/attr.rs
index 10e0ee6bb5c7..c50ccae3e8e4 100644
--- a/servo/components/script/dom/attr.rs
+++ b/servo/components/script/dom/attr.rs
@@ -64,14 +64,18 @@ impl Attr {
                prefix: Option<Prefix>,
                owner: Option<&Element>)
                -> DomRoot<Attr> {
-        reflect_dom_object(box Attr::new_inherited(local_name,
-                                                   value,
-                                                   name,
-                                                   namespace,
-                                                   prefix,
-                                                   owner),
-                           window,
-                           AttrBinding::Wrap)
+        reflect_dom_object(
+            Box::new(Attr::new_inherited(
+                local_name,
+                value,
+                name,
+                namespace,
+                prefix,
+                owner
+            )),
+            window,
+            AttrBinding::Wrap
+        )
     }
 
     #[inline]
diff --git a/servo/components/script/dom/beforeunloadevent.rs b/servo/components/script/dom/beforeunloadevent.rs
index ad1f3ee2a21a..bd7fc05daac8 100644
--- a/servo/components/script/dom/beforeunloadevent.rs
+++ b/servo/components/script/dom/beforeunloadevent.rs
@@ -33,7 +33,7 @@ impl BeforeUnloadEvent {
     }
 
     pub fn new_uninitialized(window: &Window) -> DomRoot<BeforeUnloadEvent> {
-        reflect_dom_object(box BeforeUnloadEvent::new_inherited(),
+        reflect_dom_object(Box::new(BeforeUnloadEvent::new_inherited()),
                            window,
                            BeforeUnloadEventBinding::Wrap)
     }
diff --git a/servo/components/script/dom/bindings/cell.rs b/servo/components/script/dom/bindings/cell.rs
index 2ae54fce97a1..2235e3ac7694 100644
--- a/servo/components/script/dom/bindings/cell.rs
+++ b/servo/components/script/dom/bindings/cell.rs
@@ -9,7 +9,7 @@ use style::thread_state;
 
 /// A mutable field in the DOM.
 ///
-/// This extends the API of `core::cell::RefCell` to allow unsafe access in
+/// This extends the API of `std::cell::RefCell` to allow unsafe access in
 /// certain situations, with dynamic checking in debug builds.
 #[derive(Clone, Debug, Default, HeapSizeOf, PartialEq)]
 pub struct DomRefCell<T> {
@@ -57,7 +57,7 @@ impl<T> DomRefCell<T> {
     }
 }
 
-// Functionality duplicated with `core::cell::RefCell`
+// Functionality duplicated with `std::cell::RefCell`
 // ===================================================
 impl<T> DomRefCell<T> {
     /// Create a new `DomRefCell` containing `value`.
diff --git a/servo/components/script/dom/bindings/codegen/CodegenRust.py b/servo/components/script/dom/bindings/codegen/CodegenRust.py
index a82ad040041b..d0b5e678db8e 100644
--- a/servo/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/servo/components/script/dom/bindings/codegen/CodegenRust.py
@@ -1407,7 +1407,7 @@ def getRetvalDeclarationForType(returnType, descriptorProvider):
     if returnType.isAny():
         return CGGeneric("JSVal")
     if returnType.isObject() or returnType.isSpiderMonkeyInterface():
-        result = CGGeneric("NonZero<*mut JSObject>")
+        result = CGGeneric("NonNullJSObjectPtr")
         if returnType.nullable():
             result = CGWrapper(result, pre="Option<", post=">")
         return result
@@ -2253,6 +2253,7 @@ def UnionTypes(descriptors, dictionaries, callbacks, typedefs, config):
         'dom::bindings::conversions::StringificationBehavior',
         'dom::bindings::conversions::root_from_handlevalue',
         'dom::bindings::error::throw_not_in_union',
+        'dom::bindings::nonnull::NonNullJSObjectPtr',
         'dom::bindings::mozmap::MozMap',
         'dom::bindings::root::DomRoot',
         'dom::bindings::str::ByteString',
@@ -3659,19 +3660,18 @@ class CGMemberJITInfo(CGThing):
                     call: ${opName} as *const os::raw::c_void,
                     protoID: PrototypeList::ID::${name} as u16,
                     depth: ${depth},
-                    _bitfield_1:
-                        JSJitInfo::new_bitfield_1(
-                            JSJitInfo_OpType::${opType} as u8,
-                            JSJitInfo_AliasSet::${aliasSet} as u8,
-                            JSValueType::${returnType} as u8,
-                            ${isInfallible},
-                            ${isMovable},
-                            ${isEliminatable},
-                            ${isAlwaysInSlot},
-                            ${isLazilyCachedInSlot},
-                            ${isTypedMethod},
-                            ${slotIndex} as u16,
-                        )
+                    _bitfield_1: new_jsjitinfo_bitfield_1!(
+                        JSJitInfo_OpType::${opType} as u8,
+                        JSJitInfo_AliasSet::${aliasSet} as u8,
+                        JSValueType::${returnType} as u8,
+                        ${isInfallible},
+                        ${isMovable},
+                        ${isEliminatable},
+                        ${isAlwaysInSlot},
+                        ${isLazilyCachedInSlot},
+                        ${isTypedMethod},
+                        ${slotIndex},
+                    ),
                 }
                 """,
                 opName=opName,
@@ -5574,7 +5574,6 @@ def generate_imports(config, cgthings, descriptors, callbacks=None, dictionaries
         typedefs = []
 
     return CGImports(cgthings, descriptors, callbacks, dictionaries, enums, typedefs, [
-        'core::nonzero::NonZero',
         'js',
         'js::JSCLASS_GLOBAL_SLOT_COUNT',
         'js::JSCLASS_IS_DOMJSCLASS',
@@ -5785,6 +5784,7 @@ def generate_imports(config, cgthings, descriptors, callbacks=None, dictionaries
         'dom::bindings::proxyhandler::get_expando_object',
         'dom::bindings::proxyhandler::get_property_descriptor',
         'dom::bindings::mozmap::MozMap',
+        'dom::bindings::nonnull::NonNullJSObjectPtr',
         'dom::bindings::num::Finite',
         'dom::bindings::str::ByteString',
         'dom::bindings::str::DOMString',
diff --git a/servo/components/script/dom/bindings/conversions.rs b/servo/components/script/dom/bindings/conversions.rs
index 075f681308e2..e27813d20f90 100644
--- a/servo/components/script/dom/bindings/conversions.rs
+++ b/servo/components/script/dom/bindings/conversions.rs
@@ -34,6 +34,7 @@
 
 use dom::bindings::error::{Error, Fallible};
 use dom::bindings::inheritance::Castable;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::reflector::{DomObject, Reflector};
 use dom::bindings::root::DomRoot;
@@ -53,7 +54,7 @@ use js::jsapi::{JS_GetLatin1StringCharsAndLength, JS_GetProperty, JS_GetReserved
 use js::jsapi::{JS_GetTwoByteStringCharsAndLength, JS_IsArrayObject, JS_IsExceptionPending};
 use js::jsapi::{JS_NewStringCopyN, JS_StringHasLatin1Chars, MutableHandleValue};
 use js::jsval::{ObjectValue, StringValue, UndefinedValue};
-use js::rust::{ToString, get_object_class, is_dom_class, is_dom_object, maybe_wrap_value};
+use js::rust::{ToString, get_object_class, is_dom_class, is_dom_object, maybe_wrap_value, maybe_wrap_object_value};
 use libc;
 use num_traits::Float;
 use servo_config::opts;
@@ -66,9 +67,19 @@ pub trait IDLInterface {
 }
 
 /// A trait to mark an IDL interface as deriving from another one.
-#[rustc_on_unimplemented = "The IDL interface `{Self}` is not derived from `{T}`."]
+#[cfg_attr(feature = "unstable",
+           rustc_on_unimplemented = "The IDL interface `{Self}` is not derived from `{T}`.")]
 pub trait DerivedFrom<T: Castable>: Castable {}
 
+// https://heycam.github.io/webidl/#es-object
+impl ToJSValConvertible for NonNullJSObjectPtr {
+    #[inline]
+    unsafe fn to_jsval(&self, cx: *mut JSContext, rval: MutableHandleValue) {
+        rval.set(ObjectValue(self.get()));
+        maybe_wrap_object_value(cx, rval);
+    }
+}
+
 impl<T: Float + ToJSValConvertible> ToJSValConvertible for Finite<T> {
     #[inline]
     unsafe fn to_jsval(&self, cx: *mut JSContext, rval: MutableHandleValue) {
diff --git a/servo/components/script/dom/bindings/interface.rs b/servo/components/script/dom/bindings/interface.rs
index 5604d33aa290..3cb9aab9f720 100644
--- a/servo/components/script/dom/bindings/interface.rs
+++ b/servo/components/script/dom/bindings/interface.rs
@@ -134,8 +134,8 @@ impl NonCallbackInterfaceObjectClass {
                 name: b"Function\0" as *const _ as *const libc::c_char,
                 flags: 0,
                 cOps: &constructor_behavior.0,
-                spec: ptr::null(),
-                ext: ptr::null(),
+                spec: 0 as *const _,
+                ext: 0 as *const _,
                 oOps: &OBJECT_OPS,
             },
             proto_id: proto_id,
@@ -226,7 +226,7 @@ pub unsafe fn create_global_object(
     // avoid getting trace hooks called on a partially initialized object.
     JS_SetReservedSlot(rval.get(), DOM_OBJECT_SLOT, PrivateValue(private));
     let proto_array: Box<ProtoOrIfaceArray> =
-        box [0 as *mut JSObject; PrototypeList::PROTO_OR_IFACE_LENGTH];
+        Box::new([0 as *mut JSObject; PrototypeList::PROTO_OR_IFACE_LENGTH]);
     JS_SetReservedSlot(rval.get(),
                        DOM_PROTOTYPE_SLOT,
                        PrivateValue(Box::into_raw(proto_array) as *const libc::c_void));
diff --git a/servo/components/script/dom/bindings/iterable.rs b/servo/components/script/dom/bindings/iterable.rs
index fbb9894210ea..779695918c94 100644
--- a/servo/components/script/dom/bindings/iterable.rs
+++ b/servo/components/script/dom/bindings/iterable.rs
@@ -6,17 +6,17 @@
 
 //! Implementation of `iterable<...>` and `iterable<..., ...>` WebIDL declarations.
 
-use core::nonzero::NonZero;
 use dom::bindings::codegen::Bindings::IterableIteratorBinding::IterableKeyAndValueResult;
 use dom::bindings::codegen::Bindings::IterableIteratorBinding::IterableKeyOrValueResult;
 use dom::bindings::error::Fallible;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot};
 use dom::bindings::trace::JSTraceable;
 use dom::globalscope::GlobalScope;
 use dom_struct::dom_struct;
 use js::conversions::ToJSValConvertible;
-use js::jsapi::{HandleValue, Heap, JSContext, JSObject, MutableHandleObject};
+use js::jsapi::{HandleValue, Heap, JSContext, MutableHandleObject};
 use js::jsval::UndefinedValue;
 use std::cell::Cell;
 use std::ptr;
@@ -62,18 +62,18 @@ impl<T: DomObject + JSTraceable + Iterable> IterableIterator<T> {
                type_: IteratorType,
                wrap: unsafe fn(*mut JSContext, &GlobalScope, Box<IterableIterator<T>>)
                      -> DomRoot<Self>) -> DomRoot<Self> {
-        let iterator = box IterableIterator {
+        let iterator = Box::new(IterableIterator {
             reflector: Reflector::new(),
             type_: type_,
             iterable: Dom::from_ref(iterable),
             index: Cell::new(0),
-        };
+        });
         reflect_dom_object(iterator, &*iterable.global(), wrap)
     }
 
     /// Return the next value from the iterable object.
     #[allow(non_snake_case)]
-    pub fn Next(&self, cx: *mut JSContext) -> Fallible<NonZero<*mut JSObject>> {
+    pub fn Next(&self, cx: *mut JSContext) -> Fallible<NonNullJSObjectPtr> {
         let index = self.index.get();
         rooted!(in(cx) let mut value = UndefinedValue());
         rooted!(in(cx) let mut rval = ptr::null_mut());
@@ -106,7 +106,7 @@ impl<T: DomObject + JSTraceable + Iterable> IterableIterator<T> {
         self.index.set(index + 1);
         result.map(|_| {
             assert!(!rval.is_null());
-            unsafe { NonZero::new_unchecked(rval.get()) }
+            unsafe { NonNullJSObjectPtr::new_unchecked(rval.get()) }
         })
     }
 }
diff --git a/servo/components/script/dom/bindings/mod.rs b/servo/components/script/dom/bindings/mod.rs
index f251f0bd364c..7cd905471050 100644
--- a/servo/components/script/dom/bindings/mod.rs
+++ b/servo/components/script/dom/bindings/mod.rs
@@ -144,6 +144,7 @@ pub mod interface;
 pub mod iterable;
 pub mod mozmap;
 pub mod namespace;
+pub mod nonnull;
 pub mod num;
 pub mod proxyhandler;
 pub mod refcounted;
diff --git a/servo/components/script/dom/bindings/namespace.rs b/servo/components/script/dom/bindings/namespace.rs
index 8ca1116ea1ec..c2d58ef72c33 100644
--- a/servo/components/script/dom/bindings/namespace.rs
+++ b/servo/components/script/dom/bindings/namespace.rs
@@ -8,7 +8,6 @@ use dom::bindings::guard::Guard;
 use dom::bindings::interface::{create_object, define_on_global_object};
 use js::jsapi::{HandleObject, JSClass, JSContext, JSFunctionSpec, MutableHandleObject};
 use libc;
-use std::ptr;
 
 /// The class of a namespace object.
 #[derive(Clone, Copy)]
@@ -22,8 +21,8 @@ impl NamespaceObjectClass {
         NamespaceObjectClass(JSClass {
             name: name as *const _ as *const libc::c_char,
             flags: 0,
-            cOps: ptr::null_mut(),
-            reserved: [ptr::null_mut(); 3],
+            cOps: 0 as *mut _,
+            reserved: [0 as *mut _; 3],
         })
     }
 }
diff --git a/servo/components/script/dom/bindings/nonnull.rs b/servo/components/script/dom/bindings/nonnull.rs
new file mode 100644
index 000000000000..36dade7136b8
--- /dev/null
+++ b/servo/components/script/dom/bindings/nonnull.rs
@@ -0,0 +1,24 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! A wrapper type for `NonZero<*mut JSObject>`, to enable local trait impls
+
+use js::jsapi::JSObject;
+use nonzero::NonZero;
+
+/// A wrapper type for `NonZero<*mut JSObject>`, to enable local trait impls
+#[derive(Clone, Copy)]
+pub struct NonNullJSObjectPtr(NonZero<*mut JSObject>);
+
+impl NonNullJSObjectPtr {
+    #[inline]
+    pub unsafe fn new_unchecked(ptr: *mut JSObject) -> Self {
+        NonNullJSObjectPtr(NonZero::new_unchecked(ptr))
+    }
+
+    #[inline]
+    pub fn get(self) -> *mut JSObject {
+        self.0.get()
+    }
+}
diff --git a/servo/components/script/dom/bindings/root.rs b/servo/components/script/dom/bindings/root.rs
index 5aaa806ceaf8..875259004489 100644
--- a/servo/components/script/dom/bindings/root.rs
+++ b/servo/components/script/dom/bindings/root.rs
@@ -24,7 +24,6 @@
 //! originating `DomRoot<T>`.
 //!
 
-use core::nonzero::NonZero;
 use dom::bindings::conversions::DerivedFrom;
 use dom::bindings::inheritance::Castable;
 use dom::bindings::reflector::{DomObject, Reflector};
@@ -35,12 +34,11 @@ use heapsize::HeapSizeOf;
 use js::jsapi::{JSObject, JSTracer, Heap};
 use js::rust::GCMethods;
 use mitochondria::OnceCell;
+use nonzero::NonZero;
 use script_layout_interface::TrustedNodeAddress;
 use std::cell::{Cell, UnsafeCell};
 use std::default::Default;
 use std::hash::{Hash, Hasher};
-#[cfg(debug_assertions)]
-use std::intrinsics::type_name;
 use std::marker::PhantomData;
 use std::mem;
 use std::ops::Deref;
@@ -359,11 +357,11 @@ impl<T: DomObject> Deref for Dom<T> {
 
 unsafe impl<T: DomObject> JSTraceable for Dom<T> {
     unsafe fn trace(&self, trc: *mut JSTracer) {
-        #[cfg(debug_assertions)]
-        let trace_str = format!("for {} on heap", type_name::<T>());
-        #[cfg(debug_assertions)]
+        #[cfg(all(feature = "unstable", debug_assertions))]
+        let trace_str = format!("for {} on heap", ::std::intrinsics::type_name::<T>());
+        #[cfg(all(feature = "unstable", debug_assertions))]
         let trace_info = &trace_str[..];
-        #[cfg(not(debug_assertions))]
+        #[cfg(not(all(feature = "unstable", debug_assertions)))]
         let trace_info = "for DOM object on heap";
 
         trace_reflector(trc,
diff --git a/servo/components/script/dom/bindings/trace.rs b/servo/components/script/dom/bindings/trace.rs
index c367df5ee560..5c7723f17de5 100644
--- a/servo/components/script/dom/bindings/trace.rs
+++ b/servo/components/script/dom/bindings/trace.rs
@@ -110,7 +110,7 @@ use style::stylesheets::keyframes_rule::Keyframe;
 use style::values::specified::Length;
 use time::Duration;
 use uuid::Uuid;
-use webrender_api::ImageKey;
+use webrender_api::{DocumentId, ImageKey};
 use webvr_traits::WebVRGamepadHand;
 
 /// A trait to allow tracing (only) DOM objects.
@@ -397,6 +397,7 @@ unsafe_no_jsmanaged_fields!(OpaqueStyleAndLayoutData);
 unsafe_no_jsmanaged_fields!(PathBuf);
 unsafe_no_jsmanaged_fields!(CSSErrorReporter);
 unsafe_no_jsmanaged_fields!(DrawAPaintImageResult);
+unsafe_no_jsmanaged_fields!(DocumentId);
 unsafe_no_jsmanaged_fields!(ImageKey);
 unsafe_no_jsmanaged_fields!(WebGLBufferId);
 unsafe_no_jsmanaged_fields!(WebGLChan);
@@ -759,7 +760,7 @@ unsafe impl<T: JSTraceable + 'static> JSTraceable for RootedTraceableBox<T> {
 impl<T: JSTraceable + 'static> RootedTraceableBox<T> {
     /// DomRoot a JSTraceable thing for the life of this RootedTraceable
     pub fn new(traceable: T) -> RootedTraceableBox<T> {
-        let traceable = Box::into_raw(box traceable);
+        let traceable = Box::into_raw(Box::new(traceable));
         unsafe {
             RootedTraceableSet::add(traceable);
         }
diff --git a/servo/components/script/dom/bindings/weakref.rs b/servo/components/script/dom/bindings/weakref.rs
index 885fa62cdc1b..36eac4c4f32e 100644
--- a/servo/components/script/dom/bindings/weakref.rs
+++ b/servo/components/script/dom/bindings/weakref.rs
@@ -11,7 +11,6 @@
 //! slot. When all associated `WeakRef` values are dropped, the
 //! `WeakBox` itself is dropped too.
 
-use core::nonzero::NonZero;
 use dom::bindings::reflector::DomObject;
 use dom::bindings::root::DomRoot;
 use dom::bindings::trace::JSTraceable;
@@ -19,6 +18,7 @@ use heapsize::HeapSizeOf;
 use js::jsapi::{JSTracer, JS_GetReservedSlot, JS_SetReservedSlot};
 use js::jsval::PrivateValue;
 use libc::c_void;
+use nonzero::NonZero;
 use std::cell::{Cell, UnsafeCell};
 use std::mem;
 use std::ops::{Deref, DerefMut, Drop};
@@ -56,10 +56,10 @@ pub trait WeakReferenceable: DomObject + Sized {
                               .to_private() as *mut WeakBox<Self>;
             if ptr.is_null() {
                 trace!("Creating new WeakBox holder for {:p}.", self);
-                ptr = Box::into_raw(box WeakBox {
+                ptr = Box::into_raw(Box::new(WeakBox {
                     count: Cell::new(1),
                     value: Cell::new(Some(NonZero::new_unchecked(self))),
-                });
+                }));
                 JS_SetReservedSlot(object, DOM_WEAK_SLOT, PrivateValue(ptr as *const c_void));
             }
             let box_ = &*ptr;
diff --git a/servo/components/script/dom/blob.rs b/servo/components/script/dom/blob.rs
index 66dcc5b475cc..4b30249d1d55 100644
--- a/servo/components/script/dom/blob.rs
+++ b/servo/components/script/dom/blob.rs
@@ -80,7 +80,7 @@ impl Blob {
     pub fn new(
             global: &GlobalScope, blob_impl: BlobImpl, typeString: String)
             -> DomRoot<Blob> {
-        let boxed_blob = box Blob::new_inherited(blob_impl, typeString);
+        let boxed_blob = Box::new(Blob::new_inherited(blob_impl, typeString));
         reflect_dom_object(boxed_blob, global, BlobBinding::Wrap)
     }
 
diff --git a/servo/components/script/dom/bluetooth.rs b/servo/components/script/dom/bluetooth.rs
index ac3b9b7ea53b..f9ab60ec59c8 100644
--- a/servo/components/script/dom/bluetooth.rs
+++ b/servo/components/script/dom/bluetooth.rs
@@ -7,7 +7,6 @@ use bluetooth_traits::{BluetoothResponse, BluetoothResponseResult};
 use bluetooth_traits::blocklist::{Blocklist, uuid_is_blocklisted};
 use bluetooth_traits::scanfilter::{BluetoothScanfilter, BluetoothScanfilterSequence};
 use bluetooth_traits::scanfilter::{RequestDeviceoptions, ServiceUUIDSequence};
-use core::clone::Clone;
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::BluetoothBinding::{self, BluetoothDataFilterInit, BluetoothLEScanFilterInit};
 use dom::bindings::codegen::Bindings::BluetoothBinding::{BluetoothMethods, RequestDeviceOptions};
@@ -132,7 +131,7 @@ impl Bluetooth {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<Bluetooth> {
-        reflect_dom_object(box Bluetooth::new_inherited(),
+        reflect_dom_object(Box::new(Bluetooth::new_inherited()),
                            global,
                            BluetoothBinding::Wrap)
     }
@@ -224,7 +223,7 @@ pub fn response_async<T: AsyncBluetoothListener + DomObject + 'static>(
         promise: Some(TrustedPromise::new(promise.clone())),
         receiver: Trusted::new(receiver),
     }));
-    ROUTER.add_route(action_receiver.to_opaque(), box move |message| {
+    ROUTER.add_route(action_receiver.to_opaque(), Box::new(move |message| {
         struct ListenerTask<T: AsyncBluetoothListener + DomObject> {
             context: Arc<Mutex<BluetoothContext<T>>>,
             action: BluetoothResponseResult,
@@ -249,7 +248,7 @@ pub fn response_async<T: AsyncBluetoothListener + DomObject + 'static>(
         if let Err(err) = result {
             warn!("failed to deliver network data: {:?}", err);
         }
-    });
+    }));
     action_sender
 }
 
diff --git a/servo/components/script/dom/bluetoothadvertisingevent.rs b/servo/components/script/dom/bluetoothadvertisingevent.rs
index 9477c998587c..452c43eac985 100644
--- a/servo/components/script/dom/bluetoothadvertisingevent.rs
+++ b/servo/components/script/dom/bluetoothadvertisingevent.rs
@@ -55,13 +55,17 @@ impl BluetoothAdvertisingEvent {
                txPower: Option<i8>,
                rssi: Option<i8>)
                -> DomRoot<BluetoothAdvertisingEvent> {
-        let ev = reflect_dom_object(box BluetoothAdvertisingEvent::new_inherited(device,
-                                                                                 name,
-                                                                                 appearance,
-                                                                                 txPower,
-                                                                                 rssi),
-                                    global,
-                                    BluetoothAdvertisingEventBinding::Wrap);
+        let ev = reflect_dom_object(
+            Box::new(BluetoothAdvertisingEvent::new_inherited(
+                device,
+                name,
+                appearance,
+                txPower,
+                rssi
+            )),
+            global,
+            BluetoothAdvertisingEventBinding::Wrap
+        );
         {
             let event = ev.upcast::<Event>();
             event.init_event(type_, bool::from(bubbles), bool::from(cancelable));
diff --git a/servo/components/script/dom/bluetoothcharacteristicproperties.rs b/servo/components/script/dom/bluetoothcharacteristicproperties.rs
index 048e52765c8f..4a0b60292240 100644
--- a/servo/components/script/dom/bluetoothcharacteristicproperties.rs
+++ b/servo/components/script/dom/bluetoothcharacteristicproperties.rs
@@ -61,19 +61,23 @@ impl BluetoothCharacteristicProperties {
                reliableWrite: bool,
                writableAuxiliaries: bool)
                -> DomRoot<BluetoothCharacteristicProperties> {
-        reflect_dom_object(box BluetoothCharacteristicProperties::new_inherited(broadcast,
-                                                                                read,
-                                                                                writeWithoutResponse,
-                                                                                write,
-                                                                                notify,
-                                                                                indicate,
-                                                                                authenticatedSignedWrites,
-                                                                                reliableWrite,
-                                                                                writableAuxiliaries),
-                           global,
-                           BluetoothCharacteristicPropertiesBinding::Wrap)
-        }
+        reflect_dom_object(
+            Box::new(BluetoothCharacteristicProperties::new_inherited(
+                broadcast,
+                read,
+                writeWithoutResponse,
+                write,
+                notify,
+                indicate,
+                authenticatedSignedWrites,
+                reliableWrite,
+                writableAuxiliaries
+            )),
+            global,
+            BluetoothCharacteristicPropertiesBinding::Wrap
+        )
     }
+}
 
 impl BluetoothCharacteristicPropertiesMethods for BluetoothCharacteristicProperties {
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothcharacteristicproperties-broadcast
diff --git a/servo/components/script/dom/bluetoothdevice.rs b/servo/components/script/dom/bluetoothdevice.rs
index 6c6dc5c9d6e1..6fcdf40f3ff9 100644
--- a/servo/components/script/dom/bluetoothdevice.rs
+++ b/servo/components/script/dom/bluetoothdevice.rs
@@ -66,9 +66,7 @@ impl BluetoothDevice {
                name: Option<DOMString>,
                context: &Bluetooth)
                -> DomRoot<BluetoothDevice> {
-        reflect_dom_object(box BluetoothDevice::new_inherited(id,
-                                                              name,
-                                                              context),
+        reflect_dom_object(Box::new(BluetoothDevice::new_inherited(id, name, context)),
                            global,
                            BluetoothDeviceBinding::Wrap)
     }
diff --git a/servo/components/script/dom/bluetoothpermissionresult.rs b/servo/components/script/dom/bluetoothpermissionresult.rs
index ea1097c1f293..047325c5ed37 100644
--- a/servo/components/script/dom/bluetoothpermissionresult.rs
+++ b/servo/components/script/dom/bluetoothpermissionresult.rs
@@ -41,7 +41,7 @@ impl BluetoothPermissionResult {
     }
 
     pub fn new(global: &GlobalScope, status: &PermissionStatus) -> DomRoot<BluetoothPermissionResult> {
-        reflect_dom_object(box BluetoothPermissionResult::new_inherited(status),
+        reflect_dom_object(Box::new(BluetoothPermissionResult::new_inherited(status)),
                            global,
                            BluetoothPermissionResultBinding::Wrap)
     }
diff --git a/servo/components/script/dom/bluetoothremotegattcharacteristic.rs b/servo/components/script/dom/bluetoothremotegattcharacteristic.rs
index d322d0494b4f..20037c9920ca 100644
--- a/servo/components/script/dom/bluetoothremotegattcharacteristic.rs
+++ b/servo/components/script/dom/bluetoothremotegattcharacteristic.rs
@@ -65,12 +65,13 @@ impl BluetoothRemoteGATTCharacteristic {
                properties: &BluetoothCharacteristicProperties,
                instanceID: String)
                -> DomRoot<BluetoothRemoteGATTCharacteristic> {
-        reflect_dom_object(box BluetoothRemoteGATTCharacteristic::new_inherited(service,
-                                                                                uuid,
-                                                                                properties,
-                                                                                instanceID),
-                           global,
-                           BluetoothRemoteGATTCharacteristicBinding::Wrap)
+        reflect_dom_object(
+            Box::new(BluetoothRemoteGATTCharacteristic::new_inherited(
+                service, uuid, properties, instanceID
+            )),
+            global,
+            BluetoothRemoteGATTCharacteristicBinding::Wrap
+        )
     }
 
     fn get_bluetooth_thread(&self) -> IpcSender<BluetoothRequest> {
diff --git a/servo/components/script/dom/bluetoothremotegattdescriptor.rs b/servo/components/script/dom/bluetoothremotegattdescriptor.rs
index 03ae0aa5651e..94023d6ffa0e 100644
--- a/servo/components/script/dom/bluetoothremotegattdescriptor.rs
+++ b/servo/components/script/dom/bluetoothremotegattdescriptor.rs
@@ -52,11 +52,13 @@ impl BluetoothRemoteGATTDescriptor {
                uuid: DOMString,
                instanceID: String)
                -> DomRoot<BluetoothRemoteGATTDescriptor>{
-        reflect_dom_object(box BluetoothRemoteGATTDescriptor::new_inherited(characteristic,
-                                                                            uuid,
-                                                                            instanceID),
-                            global,
-                            BluetoothRemoteGATTDescriptorBinding::Wrap)
+        reflect_dom_object(
+            Box::new(BluetoothRemoteGATTDescriptor::new_inherited(
+                characteristic, uuid, instanceID
+            )),
+            global,
+            BluetoothRemoteGATTDescriptorBinding::Wrap
+        )
     }
 
     fn get_bluetooth_thread(&self) -> IpcSender<BluetoothRequest> {
diff --git a/servo/components/script/dom/bluetoothremotegattserver.rs b/servo/components/script/dom/bluetoothremotegattserver.rs
index dbc477456c6b..2c2fb3da3512 100644
--- a/servo/components/script/dom/bluetoothremotegattserver.rs
+++ b/servo/components/script/dom/bluetoothremotegattserver.rs
@@ -38,7 +38,7 @@ impl BluetoothRemoteGATTServer {
     }
 
     pub fn new(global: &GlobalScope, device: &BluetoothDevice) -> DomRoot<BluetoothRemoteGATTServer> {
-        reflect_dom_object(box BluetoothRemoteGATTServer::new_inherited(device),
+        reflect_dom_object(Box::new(BluetoothRemoteGATTServer::new_inherited(device)),
                            global,
                            BluetoothRemoteGATTServerBinding::Wrap)
     }
diff --git a/servo/components/script/dom/bluetoothremotegattservice.rs b/servo/components/script/dom/bluetoothremotegattservice.rs
index acb81f1f9a1d..74568b9a7df0 100644
--- a/servo/components/script/dom/bluetoothremotegattservice.rs
+++ b/servo/components/script/dom/bluetoothremotegattservice.rs
@@ -50,12 +50,13 @@ impl BluetoothRemoteGATTService {
                isPrimary: bool,
                instanceID: String)
                -> DomRoot<BluetoothRemoteGATTService> {
-        reflect_dom_object(box BluetoothRemoteGATTService::new_inherited(device,
-                                                                         uuid,
-                                                                         isPrimary,
-                                                                         instanceID),
-                           global,
-                           BluetoothRemoteGATTServiceBinding::Wrap)
+        reflect_dom_object(
+            Box::new(BluetoothRemoteGATTService::new_inherited(
+                device, uuid, isPrimary, instanceID
+            )),
+            global,
+            BluetoothRemoteGATTServiceBinding::Wrap
+        )
     }
 
     fn get_instance_id(&self) -> String {
diff --git a/servo/components/script/dom/canvasgradient.rs b/servo/components/script/dom/canvasgradient.rs
index 21bd0c3a0d1c..6ae52be67649 100644
--- a/servo/components/script/dom/canvasgradient.rs
+++ b/servo/components/script/dom/canvasgradient.rs
@@ -40,7 +40,7 @@ impl CanvasGradient {
     }
 
     pub fn new(global: &GlobalScope, style: CanvasGradientStyle) -> DomRoot<CanvasGradient> {
-        reflect_dom_object(box CanvasGradient::new_inherited(style),
+        reflect_dom_object(Box::new(CanvasGradient::new_inherited(style)),
                            global,
                            CanvasGradientBinding::Wrap)
     }
diff --git a/servo/components/script/dom/canvaspattern.rs b/servo/components/script/dom/canvaspattern.rs
index 5c1a7edaf75e..d1bf89f3e632 100644
--- a/servo/components/script/dom/canvaspattern.rs
+++ b/servo/components/script/dom/canvaspattern.rs
@@ -50,10 +50,13 @@ impl CanvasPattern {
                repeat: RepetitionStyle,
                origin_clean: bool)
                -> DomRoot<CanvasPattern> {
-        reflect_dom_object(box CanvasPattern::new_inherited(surface_data, surface_size,
-                                                            repeat, origin_clean),
-                           global,
-                           CanvasPatternBinding::Wrap)
+        reflect_dom_object(
+            Box::new(CanvasPattern::new_inherited(
+                surface_data, surface_size, repeat, origin_clean
+            )),
+            global,
+            CanvasPatternBinding::Wrap
+        )
     }
     pub fn origin_is_clean(&self) -> bool {
       self.origin_clean
diff --git a/servo/components/script/dom/canvasrenderingcontext2d.rs b/servo/components/script/dom/canvasrenderingcontext2d.rs
index de56cb28debb..69cf670efe4a 100644
--- a/servo/components/script/dom/canvasrenderingcontext2d.rs
+++ b/servo/components/script/dom/canvasrenderingcontext2d.rs
@@ -155,7 +155,9 @@ impl CanvasRenderingContext2D {
         let window = window_from_node(canvas);
         let image_cache = window.image_cache();
         let base_url = window.get_url();
-        let boxed = box CanvasRenderingContext2D::new_inherited(global, Some(canvas), image_cache, base_url, size);
+        let boxed = Box::new(CanvasRenderingContext2D::new_inherited(
+            global, Some(canvas), image_cache, base_url, size
+        ));
         reflect_dom_object(boxed, global, CanvasRenderingContext2DBinding::Wrap)
     }
 
diff --git a/servo/components/script/dom/client.rs b/servo/components/script/dom/client.rs
index e4bb8f137a1d..94ddc15535f6 100644
--- a/servo/components/script/dom/client.rs
+++ b/servo/components/script/dom/client.rs
@@ -36,7 +36,7 @@ impl Client {
     }
 
     pub fn new(window: &Window) -> DomRoot<Client> {
-        reflect_dom_object(box Client::new_inherited(window.get_url()),
+        reflect_dom_object(Box::new(Client::new_inherited(window.get_url())),
                            window,
                            Wrap)
     }
diff --git a/servo/components/script/dom/closeevent.rs b/servo/components/script/dom/closeevent.rs
index ef25e97c945f..1675d8b27e39 100644
--- a/servo/components/script/dom/closeevent.rs
+++ b/servo/components/script/dom/closeevent.rs
@@ -34,7 +34,7 @@ impl CloseEvent {
     }
 
     pub fn new_uninitialized(global: &GlobalScope) -> DomRoot<CloseEvent> {
-        reflect_dom_object(box CloseEvent::new_inherited(false, 0, DOMString::new()),
+        reflect_dom_object(Box::new(CloseEvent::new_inherited(false, 0, DOMString::new())),
                            global,
                            CloseEventBinding::Wrap)
     }
@@ -47,7 +47,7 @@ impl CloseEvent {
                code: u16,
                reason: DOMString)
                -> DomRoot<CloseEvent> {
-        let event = box CloseEvent::new_inherited(wasClean, code, reason);
+        let event = Box::new(CloseEvent::new_inherited(wasClean, code, reason));
         let ev = reflect_dom_object(event, global, CloseEventBinding::Wrap);
         {
             let event = ev.upcast::<Event>();
diff --git a/servo/components/script/dom/comment.rs b/servo/components/script/dom/comment.rs
index a42ba542eb5f..3eb6175e20c9 100644
--- a/servo/components/script/dom/comment.rs
+++ b/servo/components/script/dom/comment.rs
@@ -27,7 +27,7 @@ impl Comment {
     }
 
     pub fn new(text: DOMString, document: &Document) -> DomRoot<Comment> {
-        Node::reflect_node(box Comment::new_inherited(text, document),
+        Node::reflect_node(Box::new(Comment::new_inherited(text, document)),
                            document,
                            CommentBinding::Wrap)
     }
diff --git a/servo/components/script/dom/compositionevent.rs b/servo/components/script/dom/compositionevent.rs
index f28f9229742c..dc93427dbed1 100644
--- a/servo/components/script/dom/compositionevent.rs
+++ b/servo/components/script/dom/compositionevent.rs
@@ -26,10 +26,10 @@ impl CompositionEvent {
                view: Option<&Window>,
                detail: i32,
                data: DOMString) -> DomRoot<CompositionEvent> {
-        let ev = reflect_dom_object(box CompositionEvent {
+        let ev = reflect_dom_object(Box::new(CompositionEvent {
                                         uievent: UIEvent::new_inherited(),
                                         data: data,
-                                    },
+                                    }),
                                     window,
                                     CompositionEventBinding::Wrap);
         ev.uievent.InitUIEvent(type_, can_bubble, cancelable, view, detail);
diff --git a/servo/components/script/dom/crypto.rs b/servo/components/script/dom/crypto.rs
index e6c6354557f8..ac56e9f3ff62 100644
--- a/servo/components/script/dom/crypto.rs
+++ b/servo/components/script/dom/crypto.rs
@@ -2,11 +2,11 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use core::nonzero::NonZero;
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::CryptoBinding;
 use dom::bindings::codegen::Bindings::CryptoBinding::CryptoMethods;
 use dom::bindings::error::{Error, Fallible};
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
 use dom::globalscope::GlobalScope;
@@ -34,7 +34,7 @@ impl Crypto {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<Crypto> {
-        reflect_dom_object(box Crypto::new_inherited(), global, CryptoBinding::Wrap)
+        reflect_dom_object(Box::new(Crypto::new_inherited()), global, CryptoBinding::Wrap)
     }
 }
 
@@ -44,7 +44,7 @@ impl CryptoMethods for Crypto {
     unsafe fn GetRandomValues(&self,
                        _cx: *mut JSContext,
                        input: *mut JSObject)
-                       -> Fallible<NonZero<*mut JSObject>> {
+                       -> Fallible<NonNullJSObjectPtr> {
         assert!(!input.is_null());
         typedarray!(in(_cx) let mut array_buffer_view: ArrayBufferView = input);
         let (array_type, mut data) = match array_buffer_view.as_mut() {
@@ -65,7 +65,7 @@ impl CryptoMethods for Crypto {
 
         self.rng.borrow_mut().fill_bytes(&mut data);
 
-        Ok(NonZero::new_unchecked(input))
+        Ok(NonNullJSObjectPtr::new_unchecked(input))
     }
 }
 
diff --git a/servo/components/script/dom/cssfontfacerule.rs b/servo/components/script/dom/cssfontfacerule.rs
index f24c20037005..3bc836897ea8 100644
--- a/servo/components/script/dom/cssfontfacerule.rs
+++ b/servo/components/script/dom/cssfontfacerule.rs
@@ -33,7 +33,7 @@ impl CSSFontFaceRule {
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
                fontfacerule: Arc<Locked<FontFaceRule>>) -> DomRoot<CSSFontFaceRule> {
-        reflect_dom_object(box CSSFontFaceRule::new_inherited(parent_stylesheet, fontfacerule),
+        reflect_dom_object(Box::new(CSSFontFaceRule::new_inherited(parent_stylesheet, fontfacerule)),
                            window,
                            CSSFontFaceRuleBinding::Wrap)
     }
diff --git a/servo/components/script/dom/cssimportrule.rs b/servo/components/script/dom/cssimportrule.rs
index 78233b998e62..373c230ee77a 100644
--- a/servo/components/script/dom/cssimportrule.rs
+++ b/servo/components/script/dom/cssimportrule.rs
@@ -35,7 +35,7 @@ impl CSSImportRule {
     pub fn new(window: &Window,
                parent_stylesheet: &CSSStyleSheet,
                import_rule: Arc<Locked<ImportRule>>) -> DomRoot<Self> {
-        reflect_dom_object(box Self::new_inherited(parent_stylesheet, import_rule),
+        reflect_dom_object(Box::new(Self::new_inherited(parent_stylesheet, import_rule)),
                            window,
                            CSSImportRuleBinding::Wrap)
     }
diff --git a/servo/components/script/dom/csskeyframerule.rs b/servo/components/script/dom/csskeyframerule.rs
index e1883d33af35..f62d73f0b462 100644
--- a/servo/components/script/dom/csskeyframerule.rs
+++ b/servo/components/script/dom/csskeyframerule.rs
@@ -37,7 +37,7 @@ impl CSSKeyframeRule {
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
                keyframerule: Arc<Locked<Keyframe>>) -> DomRoot<CSSKeyframeRule> {
-        reflect_dom_object(box CSSKeyframeRule::new_inherited(parent_stylesheet, keyframerule),
+        reflect_dom_object(Box::new(CSSKeyframeRule::new_inherited(parent_stylesheet, keyframerule)),
                            window,
                            CSSKeyframeRuleBinding::Wrap)
     }
diff --git a/servo/components/script/dom/csskeyframesrule.rs b/servo/components/script/dom/csskeyframesrule.rs
index 407a3f78ff1e..955f0c04fb56 100644
--- a/servo/components/script/dom/csskeyframesrule.rs
+++ b/servo/components/script/dom/csskeyframesrule.rs
@@ -42,7 +42,7 @@ impl CSSKeyframesRule {
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
                keyframesrule: Arc<Locked<KeyframesRule>>) -> DomRoot<CSSKeyframesRule> {
-        reflect_dom_object(box CSSKeyframesRule::new_inherited(parent_stylesheet, keyframesrule),
+        reflect_dom_object(Box::new(CSSKeyframesRule::new_inherited(parent_stylesheet, keyframesrule)),
                            window,
                            CSSKeyframesRuleBinding::Wrap)
     }
diff --git a/servo/components/script/dom/cssmediarule.rs b/servo/components/script/dom/cssmediarule.rs
index 3bf34bc6cf56..dbfda701af57 100644
--- a/servo/components/script/dom/cssmediarule.rs
+++ b/servo/components/script/dom/cssmediarule.rs
@@ -45,7 +45,7 @@ impl CSSMediaRule {
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
                mediarule: Arc<Locked<MediaRule>>) -> DomRoot<CSSMediaRule> {
-        reflect_dom_object(box CSSMediaRule::new_inherited(parent_stylesheet, mediarule),
+        reflect_dom_object(Box::new(CSSMediaRule::new_inherited(parent_stylesheet, mediarule)),
                            window,
                            CSSMediaRuleBinding::Wrap)
     }
diff --git a/servo/components/script/dom/cssnamespacerule.rs b/servo/components/script/dom/cssnamespacerule.rs
index 0d5768d646f7..400472526802 100644
--- a/servo/components/script/dom/cssnamespacerule.rs
+++ b/servo/components/script/dom/cssnamespacerule.rs
@@ -34,7 +34,7 @@ impl CSSNamespaceRule {
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
                namespacerule: Arc<Locked<NamespaceRule>>) -> DomRoot<CSSNamespaceRule> {
-        reflect_dom_object(box CSSNamespaceRule::new_inherited(parent_stylesheet, namespacerule),
+        reflect_dom_object(Box::new(CSSNamespaceRule::new_inherited(parent_stylesheet, namespacerule)),
                            window,
                            CSSNamespaceRuleBinding::Wrap)
     }
diff --git a/servo/components/script/dom/cssrulelist.rs b/servo/components/script/dom/cssrulelist.rs
index c33005d0a575..81b58afc0f8d 100644
--- a/servo/components/script/dom/cssrulelist.rs
+++ b/servo/components/script/dom/cssrulelist.rs
@@ -71,7 +71,7 @@ impl CSSRuleList {
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
                rules: RulesSource) -> DomRoot<CSSRuleList> {
-        reflect_dom_object(box CSSRuleList::new_inherited(parent_stylesheet, rules),
+        reflect_dom_object(Box::new(CSSRuleList::new_inherited(parent_stylesheet, rules)),
                            window,
                            CSSRuleListBinding::Wrap)
     }
diff --git a/servo/components/script/dom/cssstyledeclaration.rs b/servo/components/script/dom/cssstyledeclaration.rs
index 71220f6e87b4..f7264d9f5d05 100644
--- a/servo/components/script/dom/cssstyledeclaration.rs
+++ b/servo/components/script/dom/cssstyledeclaration.rs
@@ -193,11 +193,11 @@ impl CSSStyleDeclaration {
                pseudo: Option<PseudoElement>,
                modification_access: CSSModificationAccess)
                -> DomRoot<CSSStyleDeclaration> {
-        reflect_dom_object(box CSSStyleDeclaration::new_inherited(owner,
-                                                                  pseudo,
-                                                                  modification_access),
-                           global,
-                           CSSStyleDeclarationBinding::Wrap)
+        reflect_dom_object(
+            Box::new(CSSStyleDeclaration::new_inherited(owner, pseudo, modification_access)),
+            global,
+            CSSStyleDeclarationBinding::Wrap
+        )
     }
 
     fn get_computed_style(&self, property: PropertyId) -> DOMString {
diff --git a/servo/components/script/dom/cssstylerule.rs b/servo/components/script/dom/cssstylerule.rs
index e67245f835fc..7c73bbc58c3c 100644
--- a/servo/components/script/dom/cssstylerule.rs
+++ b/servo/components/script/dom/cssstylerule.rs
@@ -43,7 +43,7 @@ impl CSSStyleRule {
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
                stylerule: Arc<Locked<StyleRule>>) -> DomRoot<CSSStyleRule> {
-        reflect_dom_object(box CSSStyleRule::new_inherited(parent_stylesheet, stylerule),
+        reflect_dom_object(Box::new(CSSStyleRule::new_inherited(parent_stylesheet, stylerule)),
                            window,
                            CSSStyleRuleBinding::Wrap)
     }
diff --git a/servo/components/script/dom/cssstylesheet.rs b/servo/components/script/dom/cssstylesheet.rs
index bf8f34977b16..de3d3cc0f6d6 100644
--- a/servo/components/script/dom/cssstylesheet.rs
+++ b/servo/components/script/dom/cssstylesheet.rs
@@ -51,7 +51,7 @@ impl CSSStyleSheet {
                href: Option<DOMString>,
                title: Option<DOMString>,
                stylesheet: Arc<StyleStyleSheet>) -> DomRoot<CSSStyleSheet> {
-        reflect_dom_object(box CSSStyleSheet::new_inherited(owner, type_, href, title, stylesheet),
+        reflect_dom_object(Box::new(CSSStyleSheet::new_inherited(owner, type_, href, title, stylesheet)),
                            window,
                            CSSStyleSheetBinding::Wrap)
     }
diff --git a/servo/components/script/dom/cssstylevalue.rs b/servo/components/script/dom/cssstylevalue.rs
index 30d2e75b34b2..4c8146edb1fa 100644
--- a/servo/components/script/dom/cssstylevalue.rs
+++ b/servo/components/script/dom/cssstylevalue.rs
@@ -29,7 +29,7 @@ impl CSSStyleValue {
     }
 
     pub fn new(global: &GlobalScope, value: String) -> DomRoot<CSSStyleValue> {
-        reflect_dom_object(box CSSStyleValue::new_inherited(value), global, Wrap)
+        reflect_dom_object(Box::new(CSSStyleValue::new_inherited(value)), global, Wrap)
     }
 }
 
diff --git a/servo/components/script/dom/csssupportsrule.rs b/servo/components/script/dom/csssupportsrule.rs
index fe42ebba7172..2a1e49cc36fc 100644
--- a/servo/components/script/dom/csssupportsrule.rs
+++ b/servo/components/script/dom/csssupportsrule.rs
@@ -41,7 +41,7 @@ impl CSSSupportsRule {
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
                supportsrule: Arc<Locked<SupportsRule>>) -> DomRoot<CSSSupportsRule> {
-        reflect_dom_object(box CSSSupportsRule::new_inherited(parent_stylesheet, supportsrule),
+        reflect_dom_object(Box::new(CSSSupportsRule::new_inherited(parent_stylesheet, supportsrule)),
                            window,
                            CSSSupportsRuleBinding::Wrap)
     }
diff --git a/servo/components/script/dom/cssviewportrule.rs b/servo/components/script/dom/cssviewportrule.rs
index afe845a7882b..694636be3239 100644
--- a/servo/components/script/dom/cssviewportrule.rs
+++ b/servo/components/script/dom/cssviewportrule.rs
@@ -32,7 +32,7 @@ impl CSSViewportRule {
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
                viewportrule: Arc<Locked<ViewportRule>>) -> DomRoot<CSSViewportRule> {
-        reflect_dom_object(box CSSViewportRule::new_inherited(parent_stylesheet, viewportrule),
+        reflect_dom_object(Box::new(CSSViewportRule::new_inherited(parent_stylesheet, viewportrule)),
                            window,
                            CSSViewportRuleBinding::Wrap)
     }
diff --git a/servo/components/script/dom/customelementregistry.rs b/servo/components/script/dom/customelementregistry.rs
index 912a4038a81d..da617e2787bf 100644
--- a/servo/components/script/dom/customelementregistry.rs
+++ b/servo/components/script/dom/customelementregistry.rs
@@ -68,7 +68,7 @@ impl CustomElementRegistry {
     }
 
     pub fn new(window: &Window) -> DomRoot<CustomElementRegistry> {
-        reflect_dom_object(box CustomElementRegistry::new_inherited(window),
+        reflect_dom_object(Box::new(CustomElementRegistry::new_inherited(window)),
                            window,
                            CustomElementRegistryBinding::Wrap)
     }
diff --git a/servo/components/script/dom/customevent.rs b/servo/components/script/dom/customevent.rs
index 0c2d0a26a3a8..e78ac74bd84c 100644
--- a/servo/components/script/dom/customevent.rs
+++ b/servo/components/script/dom/customevent.rs
@@ -35,7 +35,7 @@ impl CustomEvent {
     }
 
     pub fn new_uninitialized(global: &GlobalScope) -> DomRoot<CustomEvent> {
-        reflect_dom_object(box CustomEvent::new_inherited(),
+        reflect_dom_object(Box::new(CustomEvent::new_inherited()),
                            global,
                            CustomEventBinding::Wrap)
     }
diff --git a/servo/components/script/dom/dedicatedworkerglobalscope.rs b/servo/components/script/dom/dedicatedworkerglobalscope.rs
index dc816aca6374..33f08793b564 100644
--- a/servo/components/script/dom/dedicatedworkerglobalscope.rs
+++ b/servo/components/script/dom/dedicatedworkerglobalscope.rs
@@ -133,16 +133,18 @@ impl DedicatedWorkerGlobalScope {
                closing: Arc<AtomicBool>)
                -> DomRoot<DedicatedWorkerGlobalScope> {
         let cx = runtime.cx();
-        let scope = box DedicatedWorkerGlobalScope::new_inherited(init,
-                                                                  worker_url,
-                                                                  from_devtools_receiver,
-                                                                  runtime,
-                                                                  parent_sender,
-                                                                  own_sender,
-                                                                  receiver,
-                                                                  timer_event_chan,
-                                                                  timer_event_port,
-                                                                  closing);
+        let scope = Box::new(DedicatedWorkerGlobalScope::new_inherited(
+            init,
+            worker_url,
+            from_devtools_receiver,
+            runtime,
+            parent_sender,
+            own_sender,
+            receiver,
+            timer_event_chan,
+            timer_event_port,
+            closing
+        ));
         unsafe {
             DedicatedWorkerGlobalScopeBinding::Wrap(cx, scope)
         }
@@ -193,8 +195,10 @@ impl DedicatedWorkerGlobalScope {
                                                               &init.resource_threads.sender()) {
                 Err(_) => {
                     println!("error loading script {}", serialized_worker_url);
-                    parent_sender.send(CommonScriptMsg::Task(WorkerEvent,
-                        box SimpleWorkerErrorHandler::new(worker))).unwrap();
+                    parent_sender.send(CommonScriptMsg::Task(
+                        WorkerEvent,
+                        Box::new(SimpleWorkerErrorHandler::new(worker))
+                    )).unwrap();
                     return;
                 }
                 Ok((metadata, bytes)) => (metadata, bytes)
@@ -211,10 +215,10 @@ impl DedicatedWorkerGlobalScope {
             let (timer_tx, timer_rx) = channel();
             let (timer_ipc_chan, timer_ipc_port) = ipc::channel().unwrap();
             let worker_for_route = worker.clone();
-            ROUTER.add_route(timer_ipc_port.to_opaque(), box move |message| {
+            ROUTER.add_route(timer_ipc_port.to_opaque(), Box::new(move |message| {
                 let event = message.to().unwrap();
                 timer_tx.send((worker_for_route.clone(), event)).unwrap();
-            });
+            }));
 
             let global = DedicatedWorkerGlobalScope::new(
                 init, url, devtools_mpsc_port, runtime,
@@ -257,19 +261,19 @@ impl DedicatedWorkerGlobalScope {
     }
 
     pub fn script_chan(&self) -> Box<ScriptChan + Send> {
-        box WorkerThreadWorkerChan {
+        Box::new(WorkerThreadWorkerChan {
             sender: self.own_sender.clone(),
             worker: self.worker.borrow().as_ref().unwrap().clone(),
-        }
+        })
     }
 
     pub fn new_script_pair(&self) -> (Box<ScriptChan + Send>, Box<ScriptPort + Send>) {
         let (tx, rx) = channel();
-        let chan = box SendableWorkerScriptChan {
+        let chan = Box::new(SendableWorkerScriptChan {
             sender: tx,
             worker: self.worker.borrow().as_ref().unwrap().clone(),
-        };
-        (chan, box rx)
+        });
+        (chan, Box::new(rx))
     }
 
     #[allow(unsafe_code)]
@@ -355,7 +359,7 @@ impl DedicatedWorkerGlobalScope {
     #[allow(unsafe_code)]
     pub fn forward_error_to_worker_object(&self, error_info: ErrorInfo) {
         let worker = self.worker.borrow().as_ref().unwrap().clone();
-        let task = box task!(forward_error_to_worker_object: move || {
+        let task = Box::new(task!(forward_error_to_worker_object: move || {
             let worker = worker.root();
             let global = worker.global();
 
@@ -378,7 +382,7 @@ impl DedicatedWorkerGlobalScope {
             if event_status == EventStatus::NotCanceled {
                 global.report_an_error(error_info, unsafe { NullHandleValue });
             }
-        });
+        }));
         // TODO: Should use the DOM manipulation task source.
         self.parent_sender.send(CommonScriptMsg::Task(WorkerEvent, task)).unwrap();
     }
@@ -401,9 +405,9 @@ impl DedicatedWorkerGlobalScopeMethods for DedicatedWorkerGlobalScope {
     unsafe fn PostMessage(&self, cx: *mut JSContext, message: HandleValue) -> ErrorResult {
         let data = StructuredCloneData::write(cx, message)?;
         let worker = self.worker.borrow().as_ref().unwrap().clone();
-        let task = box task!(post_worker_message: move || {
+        let task = Box::new(task!(post_worker_message: move || {
             Worker::handle_message(worker, data);
-        });
+        }));
         self.parent_sender.send(CommonScriptMsg::Task(WorkerEvent, task)).unwrap();
         Ok(())
     }
diff --git a/servo/components/script/dom/dissimilaroriginlocation.rs b/servo/components/script/dom/dissimilaroriginlocation.rs
index b75bff7620dd..5c98e20bf5ed 100644
--- a/servo/components/script/dom/dissimilaroriginlocation.rs
+++ b/servo/components/script/dom/dissimilaroriginlocation.rs
@@ -40,7 +40,7 @@ impl DissimilarOriginLocation {
     }
 
     pub fn new(window: &DissimilarOriginWindow) -> DomRoot<DissimilarOriginLocation> {
-        reflect_dom_object(box DissimilarOriginLocation::new_inherited(window),
+        reflect_dom_object(Box::new(DissimilarOriginLocation::new_inherited(window)),
                            window,
                            DissimilarOriginLocationBinding::Wrap)
     }
diff --git a/servo/components/script/dom/dissimilaroriginwindow.rs b/servo/components/script/dom/dissimilaroriginwindow.rs
index 786169f2921a..8b45164cb991 100644
--- a/servo/components/script/dom/dissimilaroriginwindow.rs
+++ b/servo/components/script/dom/dissimilaroriginwindow.rs
@@ -52,7 +52,7 @@ impl DissimilarOriginWindow {
         let cx = global_to_clone_from.get_cx();
         // Any timer events fired on this window are ignored.
         let (timer_event_chan, _) = ipc::channel().unwrap();
-        let win = box Self {
+        let win = Box::new(Self {
             globalscope: GlobalScope::new_inherited(
                 PipelineId::new(),
                 global_to_clone_from.devtools_chan().cloned(),
@@ -69,7 +69,7 @@ impl DissimilarOriginWindow {
             ),
             window_proxy: Dom::from_ref(window_proxy),
             location: Default::default(),
-        };
+        });
         unsafe { DissimilarOriginWindowBinding::Wrap(cx, win) }
     }
 
diff --git a/servo/components/script/dom/document.rs b/servo/components/script/dom/document.rs
index 7743f7d81660..f4e734ceec54 100644
--- a/servo/components/script/dom/document.rs
+++ b/servo/components/script/dom/document.rs
@@ -3,7 +3,6 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use cookie_rs;
-use core::nonzero::NonZero;
 use devtools_traits::ScriptToDevtoolsControlMsg;
 use document_loader::{DocumentLoader, LoadType};
 use dom::activation::{ActivationSource, synthetic_click_activation};
@@ -24,6 +23,7 @@ use dom::bindings::codegen::Bindings::WindowBinding::{FrameRequestCallback, Scro
 use dom::bindings::codegen::UnionTypes::NodeOrString;
 use dom::bindings::error::{Error, ErrorResult, Fallible};
 use dom::bindings::inheritance::{Castable, ElementTypeId, HTMLElementTypeId, NodeTypeId};
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::refcounted::{Trusted, TrustedPromise};
 use dom::bindings::reflector::{DomObject, reflect_dom_object};
@@ -99,7 +99,7 @@ use html5ever::{LocalName, Namespace, QualName};
 use hyper::header::{Header, SetCookie};
 use hyper_serde::Serde;
 use ipc_channel::ipc::{self, IpcSender};
-use js::jsapi::{JSContext, JSObject, JSRuntime};
+use js::jsapi::{JSContext, JSRuntime};
 use js::jsapi::JS_GetRuntime;
 use msg::constellation_msg::{ALT, CONTROL, SHIFT, SUPER};
 use msg::constellation_msg::{BrowsingContextId, Key, KeyModifiers, KeyState, TopLevelBrowsingContextId};
@@ -2312,20 +2312,24 @@ impl Document {
                referrer: Option<String>,
                referrer_policy: Option<ReferrerPolicy>)
                -> DomRoot<Document> {
-        let document = reflect_dom_object(box Document::new_inherited(window,
-                                                                      has_browsing_context,
-                                                                      url,
-                                                                      origin,
-                                                                      doctype,
-                                                                      content_type,
-                                                                      last_modified,
-                                                                      activity,
-                                                                      source,
-                                                                      doc_loader,
-                                                                      referrer,
-                                                                      referrer_policy),
-                                          window,
-                                          DocumentBinding::Wrap);
+        let document = reflect_dom_object(
+            Box::new(Document::new_inherited(
+                window,
+                has_browsing_context,
+                url,
+                origin,
+                doctype,
+                content_type,
+                last_modified,
+                activity,
+                source,
+                doc_loader,
+                referrer,
+                referrer_policy
+            )),
+            window,
+            DocumentBinding::Wrap
+        );
         {
             let node = document.upcast::<Node>();
             node.set_owner_doc(&document);
@@ -3344,7 +3348,7 @@ impl DocumentMethods for Document {
     // https://html.spec.whatwg.org/multipage/#dom-document-images
     fn Images(&self) -> DomRoot<HTMLCollection> {
         self.images.or_init(|| {
-            let filter = box ImagesFilter;
+            let filter = Box::new(ImagesFilter);
             HTMLCollection::create(&self.window, self.upcast(), filter)
         })
     }
@@ -3352,7 +3356,7 @@ impl DocumentMethods for Document {
     // https://html.spec.whatwg.org/multipage/#dom-document-embeds
     fn Embeds(&self) -> DomRoot<HTMLCollection> {
         self.embeds.or_init(|| {
-            let filter = box EmbedsFilter;
+            let filter = Box::new(EmbedsFilter);
             HTMLCollection::create(&self.window, self.upcast(), filter)
         })
     }
@@ -3365,7 +3369,7 @@ impl DocumentMethods for Document {
     // https://html.spec.whatwg.org/multipage/#dom-document-links
     fn Links(&self) -> DomRoot<HTMLCollection> {
         self.links.or_init(|| {
-            let filter = box LinksFilter;
+            let filter = Box::new(LinksFilter);
             HTMLCollection::create(&self.window, self.upcast(), filter)
         })
     }
@@ -3373,7 +3377,7 @@ impl DocumentMethods for Document {
     // https://html.spec.whatwg.org/multipage/#dom-document-forms
     fn Forms(&self) -> DomRoot<HTMLCollection> {
         self.forms.or_init(|| {
-            let filter = box FormsFilter;
+            let filter = Box::new(FormsFilter);
             HTMLCollection::create(&self.window, self.upcast(), filter)
         })
     }
@@ -3381,7 +3385,7 @@ impl DocumentMethods for Document {
     // https://html.spec.whatwg.org/multipage/#dom-document-scripts
     fn Scripts(&self) -> DomRoot<HTMLCollection> {
         self.scripts.or_init(|| {
-            let filter = box ScriptsFilter;
+            let filter = Box::new(ScriptsFilter);
             HTMLCollection::create(&self.window, self.upcast(), filter)
         })
     }
@@ -3389,7 +3393,7 @@ impl DocumentMethods for Document {
     // https://html.spec.whatwg.org/multipage/#dom-document-anchors
     fn Anchors(&self) -> DomRoot<HTMLCollection> {
         self.anchors.or_init(|| {
-            let filter = box AnchorsFilter;
+            let filter = Box::new(AnchorsFilter);
             HTMLCollection::create(&self.window, self.upcast(), filter)
         })
     }
@@ -3398,7 +3402,7 @@ impl DocumentMethods for Document {
     fn Applets(&self) -> DomRoot<HTMLCollection> {
         // FIXME: This should be return OBJECT elements containing applets.
         self.applets.or_init(|| {
-            let filter = box AppletsFilter;
+            let filter = Box::new(AppletsFilter);
             HTMLCollection::create(&self.window, self.upcast(), filter)
         })
     }
@@ -3532,7 +3536,7 @@ impl DocumentMethods for Document {
 
     #[allow(unsafe_code)]
     // https://html.spec.whatwg.org/multipage/#dom-tree-accessors:dom-document-nameditem-filter
-    unsafe fn NamedGetter(&self, _cx: *mut JSContext, name: DOMString) -> Option<NonZero<*mut JSObject>> {
+    unsafe fn NamedGetter(&self, _cx: *mut JSContext, name: DOMString) -> Option<NonNullJSObjectPtr> {
         #[derive(HeapSizeOf, JSTraceable)]
         struct NamedElementFilter {
             name: Atom,
@@ -3600,7 +3604,7 @@ impl DocumentMethods for Document {
                 if elements.peek().is_none() {
                     // TODO: Step 2.
                     // Step 3.
-                    return Some(NonZero::new_unchecked(first.reflector().get_jsobject().get()));
+                    return Some(NonNullJSObjectPtr::new_unchecked(first.reflector().get_jsobject().get()));
                 }
             } else {
                 return None;
@@ -3610,8 +3614,8 @@ impl DocumentMethods for Document {
         let filter = NamedElementFilter {
             name: name,
         };
-        let collection = HTMLCollection::create(self.window(), root, box filter);
-        Some(NonZero::new_unchecked(collection.reflector().get_jsobject().get()))
+        let collection = HTMLCollection::create(self.window(), root, Box::new(filter));
+        Some(NonNullJSObjectPtr::new_unchecked(collection.reflector().get_jsobject().get()))
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-tree-accessors:supported-property-names
diff --git a/servo/components/script/dom/documentfragment.rs b/servo/components/script/dom/documentfragment.rs
index 320d33416915..b4a0e3cd04bb 100644
--- a/servo/components/script/dom/documentfragment.rs
+++ b/servo/components/script/dom/documentfragment.rs
@@ -34,7 +34,7 @@ impl DocumentFragment {
     }
 
     pub fn new(document: &Document) -> DomRoot<DocumentFragment> {
-        Node::reflect_node(box DocumentFragment::new_inherited(document),
+        Node::reflect_node(Box::new(DocumentFragment::new_inherited(document)),
                            document,
                            DocumentFragmentBinding::Wrap)
     }
diff --git a/servo/components/script/dom/documenttype.rs b/servo/components/script/dom/documenttype.rs
index 5fd83343570c..d00ecb7ff562 100644
--- a/servo/components/script/dom/documenttype.rs
+++ b/servo/components/script/dom/documenttype.rs
@@ -42,7 +42,7 @@ impl DocumentType {
                system_id: Option<DOMString>,
                document: &Document)
                -> DomRoot<DocumentType> {
-        Node::reflect_node(box DocumentType::new_inherited(name, public_id, system_id, document),
+        Node::reflect_node(Box::new(DocumentType::new_inherited(name, public_id, system_id, document)),
                            document,
                            DocumentTypeBinding::Wrap)
     }
diff --git a/servo/components/script/dom/domexception.rs b/servo/components/script/dom/domexception.rs
index c9fc953950af..4e661dc52c77 100644
--- a/servo/components/script/dom/domexception.rs
+++ b/servo/components/script/dom/domexception.rs
@@ -52,7 +52,7 @@ impl DOMException {
     }
 
     pub fn new(global: &GlobalScope, code: DOMErrorName) -> DomRoot<DOMException> {
-        reflect_dom_object(box DOMException::new_inherited(code),
+        reflect_dom_object(Box::new(DOMException::new_inherited(code)),
                            global,
                            DOMExceptionBinding::Wrap)
     }
diff --git a/servo/components/script/dom/domimplementation.rs b/servo/components/script/dom/domimplementation.rs
index 93ba4b287ff2..9bed3c14d2fd 100644
--- a/servo/components/script/dom/domimplementation.rs
+++ b/servo/components/script/dom/domimplementation.rs
@@ -43,7 +43,7 @@ impl DOMImplementation {
 
     pub fn new(document: &Document) -> DomRoot<DOMImplementation> {
         let window = document.window();
-        reflect_dom_object(box DOMImplementation::new_inherited(document),
+        reflect_dom_object(Box::new(DOMImplementation::new_inherited(document)),
                            window,
                            DOMImplementationBinding::Wrap)
     }
diff --git a/servo/components/script/dom/dommatrix.rs b/servo/components/script/dom/dommatrix.rs
index 9bf315299f47..0eb0cc3e29eb 100644
--- a/servo/components/script/dom/dommatrix.rs
+++ b/servo/components/script/dom/dommatrix.rs
@@ -23,7 +23,7 @@ impl DOMMatrix {
     #[allow(unrooted_must_root)]
     pub fn new(global: &GlobalScope, is2D: bool, matrix: Transform3D<f64>) -> DomRoot<Self> {
         let dommatrix = Self::new_inherited(is2D, matrix);
-        reflect_dom_object(box dommatrix, global, Wrap)
+        reflect_dom_object(Box::new(dommatrix), global, Wrap)
     }
 
     pub fn new_inherited(is2D: bool, matrix: Transform3D<f64>) -> Self {
diff --git a/servo/components/script/dom/dommatrixreadonly.rs b/servo/components/script/dom/dommatrixreadonly.rs
index 82aa96ba7b7b..661cce9aa349 100644
--- a/servo/components/script/dom/dommatrixreadonly.rs
+++ b/servo/components/script/dom/dommatrixreadonly.rs
@@ -29,7 +29,7 @@ impl DOMMatrixReadOnly {
     #[allow(unrooted_must_root)]
     pub fn new(global: &GlobalScope, is2D: bool, matrix: Transform3D<f64>) -> DomRoot<Self> {
         let dommatrix = Self::new_inherited(is2D, matrix);
-        reflect_dom_object(box dommatrix, global, Wrap)
+        reflect_dom_object(Box::new(dommatrix), global, Wrap)
     }
 
     pub fn new_inherited(is2D: bool, matrix: Transform3D<f64>) -> Self {
diff --git a/servo/components/script/dom/domparser.rs b/servo/components/script/dom/domparser.rs
index 957b93f59b28..0c50b45c1622 100644
--- a/servo/components/script/dom/domparser.rs
+++ b/servo/components/script/dom/domparser.rs
@@ -37,7 +37,7 @@ impl DOMParser {
     }
 
     pub fn new(window: &Window) -> DomRoot<DOMParser> {
-        reflect_dom_object(box DOMParser::new_inherited(window),
+        reflect_dom_object(Box::new(DOMParser::new_inherited(window)),
                            window,
                            DOMParserBinding::Wrap)
     }
diff --git a/servo/components/script/dom/dompoint.rs b/servo/components/script/dom/dompoint.rs
index 8f27603a4568..9653c08a120d 100644
--- a/servo/components/script/dom/dompoint.rs
+++ b/servo/components/script/dom/dompoint.rs
@@ -25,7 +25,7 @@ impl DOMPoint {
     }
 
     pub fn new(global: &GlobalScope, x: f64, y: f64, z: f64, w: f64) -> DomRoot<DOMPoint> {
-        reflect_dom_object(box DOMPoint::new_inherited(x, y, z, w), global, Wrap)
+        reflect_dom_object(Box::new(DOMPoint::new_inherited(x, y, z, w)), global, Wrap)
     }
 
     pub fn Constructor(global: &GlobalScope,
diff --git a/servo/components/script/dom/dompointreadonly.rs b/servo/components/script/dom/dompointreadonly.rs
index 13ec9ee8c0f2..03570b273621 100644
--- a/servo/components/script/dom/dompointreadonly.rs
+++ b/servo/components/script/dom/dompointreadonly.rs
@@ -32,7 +32,7 @@ impl DOMPointReadOnly {
     }
 
     pub fn new(global: &GlobalScope, x: f64, y: f64, z: f64, w: f64) -> DomRoot<DOMPointReadOnly> {
-        reflect_dom_object(box DOMPointReadOnly::new_inherited(x, y, z, w),
+        reflect_dom_object(Box::new(DOMPointReadOnly::new_inherited(x, y, z, w)),
                            global,
                            Wrap)
     }
diff --git a/servo/components/script/dom/domquad.rs b/servo/components/script/dom/domquad.rs
index 54c07b8275c7..49c882db9bda 100644
--- a/servo/components/script/dom/domquad.rs
+++ b/servo/components/script/dom/domquad.rs
@@ -43,7 +43,7 @@ impl DOMQuad {
                p2: &DOMPoint,
                p3: &DOMPoint,
                p4: &DOMPoint) -> DomRoot<DOMQuad> {
-        reflect_dom_object(box DOMQuad::new_inherited(p1, p2, p3, p4),
+        reflect_dom_object(Box::new(DOMQuad::new_inherited(p1, p2, p3, p4)),
                            global,
                            Wrap)
     }
diff --git a/servo/components/script/dom/domrect.rs b/servo/components/script/dom/domrect.rs
index 4933619d172b..8944b0d28df9 100644
--- a/servo/components/script/dom/domrect.rs
+++ b/servo/components/script/dom/domrect.rs
@@ -25,7 +25,7 @@ impl DOMRect {
     }
 
     pub fn new(global: &GlobalScope, x: f64, y: f64, width: f64, height: f64) -> DomRoot<DOMRect> {
-        reflect_dom_object(box DOMRect::new_inherited(x, y, width, height),
+        reflect_dom_object(Box::new(DOMRect::new_inherited(x, y, width, height)),
                            global,
                            DOMRectBinding::Wrap)
     }
diff --git a/servo/components/script/dom/domrectreadonly.rs b/servo/components/script/dom/domrectreadonly.rs
index fe590b0e7491..f5e928120805 100644
--- a/servo/components/script/dom/domrectreadonly.rs
+++ b/servo/components/script/dom/domrectreadonly.rs
@@ -36,7 +36,7 @@ impl DOMRectReadOnly {
                width: f64,
                height: f64)
                -> DomRoot<DOMRectReadOnly> {
-        reflect_dom_object(box DOMRectReadOnly::new_inherited(x, y, width, height),
+        reflect_dom_object(Box::new(DOMRectReadOnly::new_inherited(x, y, width, height)),
                            global,
                            Wrap)
     }
diff --git a/servo/components/script/dom/domstringmap.rs b/servo/components/script/dom/domstringmap.rs
index c349a9d52591..c64375e0bdbe 100644
--- a/servo/components/script/dom/domstringmap.rs
+++ b/servo/components/script/dom/domstringmap.rs
@@ -28,7 +28,7 @@ impl DOMStringMap {
 
     pub fn new(element: &HTMLElement) -> DomRoot<DOMStringMap> {
         let window = window_from_node(element);
-        reflect_dom_object(box DOMStringMap::new_inherited(element),
+        reflect_dom_object(Box::new(DOMStringMap::new_inherited(element)),
                            &*window,
                            DOMStringMapBinding::Wrap)
     }
diff --git a/servo/components/script/dom/domtokenlist.rs b/servo/components/script/dom/domtokenlist.rs
index 22f0a45654bd..18999f59f13f 100644
--- a/servo/components/script/dom/domtokenlist.rs
+++ b/servo/components/script/dom/domtokenlist.rs
@@ -34,7 +34,7 @@ impl DOMTokenList {
 
     pub fn new(element: &Element, local_name: &LocalName) -> DomRoot<DOMTokenList> {
         let window = window_from_node(element);
-        reflect_dom_object(box DOMTokenList::new_inherited(element, local_name.clone()),
+        reflect_dom_object(Box::new(DOMTokenList::new_inherited(element, local_name.clone())),
                            &*window,
                            DOMTokenListBinding::Wrap)
     }
diff --git a/servo/components/script/dom/element.rs b/servo/components/script/dom/element.rs
index e877a8b07527..a908561b1cc1 100644
--- a/servo/components/script/dom/element.rs
+++ b/servo/components/script/dom/element.rs
@@ -120,6 +120,11 @@ use style::values::{CSSFloat, Either};
 use style::values::{specified, computed};
 use stylesheet_loader::StylesheetOwner;
 use task::TaskOnce;
+use xml5ever::serialize as xmlSerialize;
+use xml5ever::serialize::SerializeOpts as XmlSerializeOpts;
+use xml5ever::serialize::TraversalScope as XmlTraversalScope;
+use xml5ever::serialize::TraversalScope::ChildrenOnly as XmlChildrenOnly;
+use xml5ever::serialize::TraversalScope::IncludeNode as XmlIncludeNode;
 
 // TODO: Update focus state when the top-level browsing context gains or loses system focus,
 // and when the element enters or leaves a browsing context container.
@@ -276,7 +281,7 @@ impl Element {
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<Element> {
         Node::reflect_node(
-            box Element::new_inherited(local_name, namespace, prefix, document),
+            Box::new(Element::new_inherited(local_name, namespace, prefix, document)),
             document,
             ElementBinding::Wrap)
     }
@@ -1004,6 +1009,19 @@ impl Element {
         }
     }
 
+    pub fn xmlSerialize(&self, traversal_scope: XmlTraversalScope) -> Fallible<DOMString> {
+        let mut writer = vec![];
+        match xmlSerialize::serialize(&mut writer,
+                        &self.upcast::<Node>(),
+                        XmlSerializeOpts {
+                            traversal_scope: traversal_scope,
+                            ..Default::default()
+                        }) {
+            Ok(()) => Ok(DOMString::from(String::from_utf8(writer).unwrap())),
+            Err(_) => panic!("Cannot serialize element"),
+        }
+    }
+
     pub fn root_element(&self) -> DomRoot<Element> {
         if self.node.is_in_doc() {
             self.upcast::<Node>()
@@ -2047,11 +2065,14 @@ impl ElementMethods for Element {
 
     /// https://w3c.github.io/DOM-Parsing/#widl-Element-innerHTML
     fn GetInnerHTML(&self) -> Fallible<DOMString> {
-        // XXX TODO: XML case
         let qname = QualName::new(self.prefix().clone(),
                                   self.namespace().clone(),
                                   self.local_name().clone());
-        self.serialize(ChildrenOnly(Some(qname)))
+        if document_from_node(self).is_html_document() {
+            return self.serialize(ChildrenOnly(Some(qname)));
+        } else {
+            return self.xmlSerialize(XmlChildrenOnly(Some(qname)));
+        }
     }
 
     /// https://w3c.github.io/DOM-Parsing/#widl-Element-innerHTML
@@ -2071,7 +2092,11 @@ impl ElementMethods for Element {
 
     // https://dvcs.w3.org/hg/innerhtml/raw-file/tip/index.html#widl-Element-outerHTML
     fn GetOuterHTML(&self) -> Fallible<DOMString> {
-        self.serialize(IncludeNode)
+        if document_from_node(self).is_html_document() {
+            return self.serialize(IncludeNode);
+        } else {
+            return self.xmlSerialize(XmlIncludeNode);
+        }
     }
 
     // https://w3c.github.io/DOM-Parsing/#dom-element-outerhtml
@@ -3040,11 +3065,11 @@ pub struct ElementPerformFullscreenEnter {
 
 impl ElementPerformFullscreenEnter {
     pub fn new(element: Trusted<Element>, promise: TrustedPromise, error: bool) -> Box<ElementPerformFullscreenEnter> {
-        box ElementPerformFullscreenEnter {
+        Box::new(ElementPerformFullscreenEnter {
             element: element,
             promise: promise,
             error: error,
-        }
+        })
     }
 }
 
@@ -3083,10 +3108,10 @@ pub struct ElementPerformFullscreenExit {
 
 impl ElementPerformFullscreenExit {
     pub fn new(element: Trusted<Element>, promise: TrustedPromise) -> Box<ElementPerformFullscreenExit> {
-        box ElementPerformFullscreenExit {
+        Box::new(ElementPerformFullscreenExit {
             element: element,
             promise: promise,
-        }
+        })
     }
 }
 
diff --git a/servo/components/script/dom/errorevent.rs b/servo/components/script/dom/errorevent.rs
index cf9439484556..1703698d382c 100644
--- a/servo/components/script/dom/errorevent.rs
+++ b/servo/components/script/dom/errorevent.rs
@@ -44,7 +44,7 @@ impl ErrorEvent {
     }
 
     pub fn new_uninitialized(global: &GlobalScope) -> DomRoot<ErrorEvent> {
-        reflect_dom_object(box ErrorEvent::new_inherited(),
+        reflect_dom_object(Box::new(ErrorEvent::new_inherited()),
                            global,
                            ErrorEventBinding::Wrap)
     }
diff --git a/servo/components/script/dom/event.rs b/servo/components/script/dom/event.rs
index e693dd1c5ebd..e9313c742c6f 100644
--- a/servo/components/script/dom/event.rs
+++ b/servo/components/script/dom/event.rs
@@ -65,7 +65,7 @@ impl Event {
     }
 
     pub fn new_uninitialized(global: &GlobalScope) -> DomRoot<Event> {
-        reflect_dom_object(box Event::new_inherited(),
+        reflect_dom_object(Box::new(Event::new_inherited()),
                            global,
                            EventBinding::Wrap)
     }
diff --git a/servo/components/script/dom/eventsource.rs b/servo/components/script/dom/eventsource.rs
index 962138968d07..8da3c47ec652 100644
--- a/servo/components/script/dom/eventsource.rs
+++ b/servo/components/script/dom/eventsource.rs
@@ -413,7 +413,7 @@ impl EventSource {
     }
 
     fn new(global: &GlobalScope, url: ServoUrl, with_credentials: bool) -> DomRoot<EventSource> {
-        reflect_dom_object(box EventSource::new_inherited(url, with_credentials),
+        reflect_dom_object(Box::new(EventSource::new_inherited(url, with_credentials)),
                            global,
                            Wrap)
     }
@@ -486,9 +486,9 @@ impl EventSource {
             task_source: global.networking_task_source(),
             canceller: Some(global.task_canceller())
         };
-        ROUTER.add_route(action_receiver.to_opaque(), box move |message| {
+        ROUTER.add_route(action_receiver.to_opaque(), Box::new(move |message| {
             listener.notify_fetch(message.to().unwrap());
-        });
+        }));
         global.core_resource_thread().send(CoreResourceMsg::Fetch(request, action_sender)).unwrap();
         // Step 13
         Ok(ev)
diff --git a/servo/components/script/dom/extendableevent.rs b/servo/components/script/dom/extendableevent.rs
index 4af769b2d697..a1b3233c0404 100644
--- a/servo/components/script/dom/extendableevent.rs
+++ b/servo/components/script/dom/extendableevent.rs
@@ -34,7 +34,11 @@ impl ExtendableEvent {
                bubbles: bool,
                cancelable: bool)
                -> DomRoot<ExtendableEvent> {
-        let ev = reflect_dom_object(box ExtendableEvent::new_inherited(), worker, ExtendableEventBinding::Wrap);
+        let ev = reflect_dom_object(
+            Box::new(ExtendableEvent::new_inherited()),
+            worker,
+            ExtendableEventBinding::Wrap
+        );
         {
             let event = ev.upcast::<Event>();
             event.init_event(type_, bubbles, cancelable);
diff --git a/servo/components/script/dom/extendablemessageevent.rs b/servo/components/script/dom/extendablemessageevent.rs
index eacc3fb4e8cd..1f4586015687 100644
--- a/servo/components/script/dom/extendablemessageevent.rs
+++ b/servo/components/script/dom/extendablemessageevent.rs
@@ -33,12 +33,12 @@ impl ExtendableMessageEvent {
                bubbles: bool, cancelable: bool,
                data: HandleValue, origin: DOMString, lastEventId: DOMString)
                -> DomRoot<ExtendableMessageEvent> {
-        let ev = box ExtendableMessageEvent {
+        let ev = Box::new(ExtendableMessageEvent {
             event: ExtendableEvent::new_inherited(),
             data: Heap::default(),
             origin: origin,
             lastEventId: lastEventId,
-        };
+        });
         let ev = reflect_dom_object(ev, global, ExtendableMessageEventBinding::Wrap);
         {
             let event = ev.upcast::<Event>();
diff --git a/servo/components/script/dom/file.rs b/servo/components/script/dom/file.rs
index 1bfd12a26547..e80c92cf83b2 100644
--- a/servo/components/script/dom/file.rs
+++ b/servo/components/script/dom/file.rs
@@ -45,7 +45,7 @@ impl File {
     #[allow(unrooted_must_root)]
     pub fn new(global: &GlobalScope, blob_impl: BlobImpl,
                name: DOMString, modified: Option<i64>, typeString: &str) -> DomRoot<File> {
-        reflect_dom_object(box File::new_inherited(blob_impl, name, modified, typeString),
+        reflect_dom_object(Box::new(File::new_inherited(blob_impl, name, modified, typeString)),
                            global,
                            FileBinding::Wrap)
     }
diff --git a/servo/components/script/dom/filelist.rs b/servo/components/script/dom/filelist.rs
index 559f36cbd7c9..48dd5fdb9cad 100644
--- a/servo/components/script/dom/filelist.rs
+++ b/servo/components/script/dom/filelist.rs
@@ -29,7 +29,7 @@ impl FileList {
 
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, files: Vec<DomRoot<File>>) -> DomRoot<FileList> {
-        reflect_dom_object(box FileList::new_inherited(files.iter().map(|r| Dom::from_ref(&**r)).collect()),
+        reflect_dom_object(Box::new(FileList::new_inherited(files.iter().map(|r| Dom::from_ref(&**r)).collect())),
                            window,
                            FileListBinding::Wrap)
     }
diff --git a/servo/components/script/dom/filereader.rs b/servo/components/script/dom/filereader.rs
index 5bd964d41880..a2e211cc0034 100644
--- a/servo/components/script/dom/filereader.rs
+++ b/servo/components/script/dom/filereader.rs
@@ -104,7 +104,7 @@ impl FileReader {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<FileReader> {
-        reflect_dom_object(box FileReader::new_inherited(),
+        reflect_dom_object(Box::new(FileReader::new_inherited()),
                            global, FileReaderBinding::Wrap)
     }
 
diff --git a/servo/components/script/dom/filereadersync.rs b/servo/components/script/dom/filereadersync.rs
index a4e75f4bca54..bbdb83a23a96 100644
--- a/servo/components/script/dom/filereadersync.rs
+++ b/servo/components/script/dom/filereadersync.rs
@@ -23,7 +23,7 @@ impl FileReaderSync {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<FileReaderSync> {
-        reflect_dom_object(box FileReaderSync::new_inherited(),
+        reflect_dom_object(Box::new(FileReaderSync::new_inherited()),
                            global, FileReaderSyncBinding::Wrap)
     }
 
diff --git a/servo/components/script/dom/focusevent.rs b/servo/components/script/dom/focusevent.rs
index de689683b6b2..7966e887b4ca 100644
--- a/servo/components/script/dom/focusevent.rs
+++ b/servo/components/script/dom/focusevent.rs
@@ -32,7 +32,7 @@ impl FocusEvent {
     }
 
     pub fn new_uninitialized(window: &Window) -> DomRoot<FocusEvent> {
-        reflect_dom_object(box FocusEvent::new_inherited(),
+        reflect_dom_object(Box::new(FocusEvent::new_inherited()),
                            window,
                            FocusEventBinding::Wrap)
     }
diff --git a/servo/components/script/dom/forcetouchevent.rs b/servo/components/script/dom/forcetouchevent.rs
index b1159a578473..66d5a7de94bf 100644
--- a/servo/components/script/dom/forcetouchevent.rs
+++ b/servo/components/script/dom/forcetouchevent.rs
@@ -31,7 +31,7 @@ impl ForceTouchEvent {
     pub fn new(window: &Window,
                type_: DOMString,
                force: f32) -> DomRoot<ForceTouchEvent> {
-        let event = box ForceTouchEvent::new_inherited(force);
+        let event = Box::new(ForceTouchEvent::new_inherited(force));
         let ev = reflect_dom_object(event, window, ForceTouchEventBinding::Wrap);
         ev.upcast::<UIEvent>().InitUIEvent(type_, true, true, Some(window), 0);
         ev
diff --git a/servo/components/script/dom/formdata.rs b/servo/components/script/dom/formdata.rs
index f97b425883a2..d856a6e26f7d 100644
--- a/servo/components/script/dom/formdata.rs
+++ b/servo/components/script/dom/formdata.rs
@@ -48,7 +48,7 @@ impl FormData {
     }
 
     pub fn new(form: Option<&HTMLFormElement>, global: &GlobalScope) -> DomRoot<FormData> {
-        reflect_dom_object(box FormData::new_inherited(form),
+        reflect_dom_object(Box::new(FormData::new_inherited(form)),
                            global, FormDataWrap)
     }
 
diff --git a/servo/components/script/dom/gamepad.rs b/servo/components/script/dom/gamepad.rs
index 39e76818906e..47605b7794e6 100644
--- a/servo/components/script/dom/gamepad.rs
+++ b/servo/components/script/dom/gamepad.rs
@@ -2,10 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use core::nonzero::NonZero;
 use dom::bindings::codegen::Bindings::GamepadBinding;
 use dom::bindings::codegen::Bindings::GamepadBinding::GamepadMethods;
 use dom::bindings::inheritance::Castable;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot};
@@ -75,18 +75,22 @@ impl Gamepad {
         let buttons = GamepadButtonList::new_from_vr(&global, &state.buttons);
         let pose = VRPose::new(&global, &state.pose);
 
-        let gamepad = reflect_dom_object(box Gamepad::new_inherited(state.gamepad_id,
-                                                                    data.name.clone(),
-                                                                    index,
-                                                                    state.connected,
-                                                                    state.timestamp,
-                                                                    "".into(),
-                                                                    &buttons,
-                                                                    Some(&pose),
-                                                                    data.hand.clone(),
-                                                                    data.display_id),
-                                         global,
-                                         GamepadBinding::Wrap);
+        let gamepad = reflect_dom_object(
+            Box::new(Gamepad::new_inherited(
+                state.gamepad_id,
+                data.name.clone(),
+                index,
+                state.connected,
+                state.timestamp,
+                "".into(),
+                &buttons,
+                Some(&pose),
+                data.hand.clone(),
+                data.display_id
+            )),
+            global,
+            GamepadBinding::Wrap
+        );
 
         let cx = global.get_cx();
         rooted!(in (cx) let mut array = ptr::null_mut());
@@ -127,8 +131,8 @@ impl GamepadMethods for Gamepad {
 
     #[allow(unsafe_code)]
     // https://w3c.github.io/gamepad/#dom-gamepad-axes
-    unsafe fn Axes(&self, _cx: *mut JSContext) -> NonZero<*mut JSObject> {
-        NonZero::new_unchecked(self.axes.get())
+    unsafe fn Axes(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
+        NonNullJSObjectPtr::new_unchecked(self.axes.get())
     }
 
     // https://w3c.github.io/gamepad/#dom-gamepad-buttons
diff --git a/servo/components/script/dom/gamepadbutton.rs b/servo/components/script/dom/gamepadbutton.rs
index 1fc93941f9cc..fb5182b7cda4 100644
--- a/servo/components/script/dom/gamepadbutton.rs
+++ b/servo/components/script/dom/gamepadbutton.rs
@@ -30,7 +30,7 @@ impl GamepadButton {
     }
 
     pub fn new(global: &GlobalScope, pressed: bool, touched: bool) -> DomRoot<GamepadButton> {
-        reflect_dom_object(box GamepadButton::new_inherited(pressed, touched),
+        reflect_dom_object(Box::new(GamepadButton::new_inherited(pressed, touched)),
                            global,
                            GamepadButtonBinding::Wrap)
     }
diff --git a/servo/components/script/dom/gamepadbuttonlist.rs b/servo/components/script/dom/gamepadbuttonlist.rs
index 809760baca29..46f69fb97ad6 100644
--- a/servo/components/script/dom/gamepadbuttonlist.rs
+++ b/servo/components/script/dom/gamepadbuttonlist.rs
@@ -31,7 +31,7 @@ impl GamepadButtonList {
         rooted_vec!(let list <- buttons.iter()
                                        .map(|btn| GamepadButton::new(&global, btn.pressed, btn.touched)));
 
-        reflect_dom_object(box GamepadButtonList::new_inherited(list.r()),
+        reflect_dom_object(Box::new(GamepadButtonList::new_inherited(list.r())),
                            global,
                            GamepadButtonListBinding::Wrap)
     }
diff --git a/servo/components/script/dom/gamepadevent.rs b/servo/components/script/dom/gamepadevent.rs
index 644713be2256..f3badfdb8c42 100644
--- a/servo/components/script/dom/gamepadevent.rs
+++ b/servo/components/script/dom/gamepadevent.rs
@@ -42,9 +42,9 @@ impl GamepadEvent {
                cancelable: bool,
                gamepad: &Gamepad)
                -> DomRoot<GamepadEvent> {
-        let ev = reflect_dom_object(box GamepadEvent::new_inherited(&gamepad),
-                           global,
-                           GamepadEventBinding::Wrap);
+        let ev = reflect_dom_object(
+            Box::new(GamepadEvent::new_inherited(&gamepad)), global, GamepadEventBinding::Wrap
+        );
         {
             let event = ev.upcast::<Event>();
             event.init_event(type_, bubbles, cancelable);
diff --git a/servo/components/script/dom/gamepadlist.rs b/servo/components/script/dom/gamepadlist.rs
index bcbb71314565..f767d0013436 100644
--- a/servo/components/script/dom/gamepadlist.rs
+++ b/servo/components/script/dom/gamepadlist.rs
@@ -27,7 +27,7 @@ impl GamepadList {
     }
 
     pub fn new(global: &GlobalScope, list: &[&Gamepad]) -> DomRoot<GamepadList> {
-        reflect_dom_object(box GamepadList::new_inherited(list),
+        reflect_dom_object(Box::new(GamepadList::new_inherited(list)),
                            global,
                            GamepadListBinding::Wrap)
     }
diff --git a/servo/components/script/dom/hashchangeevent.rs b/servo/components/script/dom/hashchangeevent.rs
index 16dad9f60784..98314305fd4e 100644
--- a/servo/components/script/dom/hashchangeevent.rs
+++ b/servo/components/script/dom/hashchangeevent.rs
@@ -33,7 +33,7 @@ impl HashChangeEvent {
     }
 
     pub fn new_uninitialized(window: &Window) -> DomRoot<HashChangeEvent> {
-        reflect_dom_object(box HashChangeEvent::new_inherited(String::new(), String::new()),
+        reflect_dom_object(Box::new(HashChangeEvent::new_inherited(String::new(), String::new())),
                            window,
                            HashChangeEventBinding::Wrap)
     }
@@ -45,7 +45,7 @@ impl HashChangeEvent {
                old_url: String,
                new_url: String)
                -> DomRoot<HashChangeEvent> {
-        let ev = reflect_dom_object(box HashChangeEvent::new_inherited(old_url, new_url),
+        let ev = reflect_dom_object(Box::new(HashChangeEvent::new_inherited(old_url, new_url)),
                                     window,
                                     HashChangeEventBinding::Wrap);
         {
diff --git a/servo/components/script/dom/headers.rs b/servo/components/script/dom/headers.rs
index 2baa604b058c..9b8910bc893d 100644
--- a/servo/components/script/dom/headers.rs
+++ b/servo/components/script/dom/headers.rs
@@ -45,7 +45,7 @@ impl Headers {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<Headers> {
-        reflect_dom_object(box Headers::new_inherited(), global, HeadersWrap)
+        reflect_dom_object(Box::new(Headers::new_inherited()), global, HeadersWrap)
     }
 
     // https://fetch.spec.whatwg.org/#dom-headers
diff --git a/servo/components/script/dom/history.rs b/servo/components/script/dom/history.rs
index 9e97a3d5e955..71e8c0c7e4e6 100644
--- a/servo/components/script/dom/history.rs
+++ b/servo/components/script/dom/history.rs
@@ -33,7 +33,7 @@ impl History {
     }
 
     pub fn new(window: &Window) -> DomRoot<History> {
-        reflect_dom_object(box History::new_inherited(window),
+        reflect_dom_object(Box::new(History::new_inherited(window)),
                            window,
                            HistoryBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlanchorelement.rs b/servo/components/script/dom/htmlanchorelement.rs
index 5909480eb95d..fea65b4602db 100644
--- a/servo/components/script/dom/htmlanchorelement.rs
+++ b/servo/components/script/dom/htmlanchorelement.rs
@@ -57,7 +57,7 @@ impl HTMLAnchorElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLAnchorElement> {
-        Node::reflect_node(box HTMLAnchorElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLAnchorElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLAnchorElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlappletelement.rs b/servo/components/script/dom/htmlappletelement.rs
index a28475442837..5ab56b9616d0 100644
--- a/servo/components/script/dom/htmlappletelement.rs
+++ b/servo/components/script/dom/htmlappletelement.rs
@@ -34,7 +34,7 @@ impl HTMLAppletElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLAppletElement> {
-        Node::reflect_node(box HTMLAppletElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLAppletElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLAppletElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlareaelement.rs b/servo/components/script/dom/htmlareaelement.rs
index 859c1081e97e..e7120a20e08c 100644
--- a/servo/components/script/dom/htmlareaelement.rs
+++ b/servo/components/script/dom/htmlareaelement.rs
@@ -232,7 +232,7 @@ impl HTMLAreaElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLAreaElement> {
-        Node::reflect_node(box HTMLAreaElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLAreaElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLAreaElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlaudioelement.rs b/servo/components/script/dom/htmlaudioelement.rs
index 456baaa23168..ed33f124819c 100644
--- a/servo/components/script/dom/htmlaudioelement.rs
+++ b/servo/components/script/dom/htmlaudioelement.rs
@@ -29,7 +29,7 @@ impl HTMLAudioElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLAudioElement> {
-        Node::reflect_node(box HTMLAudioElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLAudioElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLAudioElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlbaseelement.rs b/servo/components/script/dom/htmlbaseelement.rs
index c1c3c07aaf01..858302e46ac8 100644
--- a/servo/components/script/dom/htmlbaseelement.rs
+++ b/servo/components/script/dom/htmlbaseelement.rs
@@ -33,7 +33,7 @@ impl HTMLBaseElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLBaseElement> {
-        Node::reflect_node(box HTMLBaseElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLBaseElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLBaseElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlbodyelement.rs b/servo/components/script/dom/htmlbodyelement.rs
index 69d56b31b95e..843ce1b35cb6 100644
--- a/servo/components/script/dom/htmlbodyelement.rs
+++ b/servo/components/script/dom/htmlbodyelement.rs
@@ -43,7 +43,7 @@ impl HTMLBodyElement {
     #[allow(unrooted_must_root)]
     pub fn new(local_name: LocalName, prefix: Option<Prefix>, document: &Document)
                -> DomRoot<HTMLBodyElement> {
-        Node::reflect_node(box HTMLBodyElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLBodyElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLBodyElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlbrelement.rs b/servo/components/script/dom/htmlbrelement.rs
index fa782cf35645..02845543e534 100644
--- a/servo/components/script/dom/htmlbrelement.rs
+++ b/servo/components/script/dom/htmlbrelement.rs
@@ -26,7 +26,7 @@ impl HTMLBRElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLBRElement> {
-        Node::reflect_node(box HTMLBRElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLBRElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLBRElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlbuttonelement.rs b/servo/components/script/dom/htmlbuttonelement.rs
index d72fb7521941..78ae7500712a 100755
--- a/servo/components/script/dom/htmlbuttonelement.rs
+++ b/servo/components/script/dom/htmlbuttonelement.rs
@@ -62,7 +62,7 @@ impl HTMLButtonElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLButtonElement> {
-        Node::reflect_node(box HTMLButtonElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLButtonElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLButtonElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlcanvaselement.rs b/servo/components/script/dom/htmlcanvaselement.rs
index c624d5d9fdaa..916fcce9ab65 100644
--- a/servo/components/script/dom/htmlcanvaselement.rs
+++ b/servo/components/script/dom/htmlcanvaselement.rs
@@ -68,7 +68,7 @@ impl HTMLCanvasElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLCanvasElement> {
-        Node::reflect_node(box HTMLCanvasElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLCanvasElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLCanvasElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlcollection.rs b/servo/components/script/dom/htmlcollection.rs
index cefa1407413d..19b756769bcd 100644
--- a/servo/components/script/dom/htmlcollection.rs
+++ b/servo/components/script/dom/htmlcollection.rs
@@ -82,7 +82,7 @@ impl HTMLCollection {
 
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, root: &Node, filter: Box<CollectionFilter + 'static>) -> DomRoot<HTMLCollection> {
-        reflect_dom_object(box HTMLCollection::new_inherited(root, filter),
+        reflect_dom_object(Box::new(HTMLCollection::new_inherited(root, filter)),
                            window, HTMLCollectionBinding::Wrap)
     }
 
@@ -126,7 +126,7 @@ impl HTMLCollection {
                     true
                 }
             }
-            return HTMLCollection::create(window, root, box AllFilter);
+            return HTMLCollection::create(window, root, Box::new(AllFilter));
         }
 
         #[derive(HeapSizeOf, JSTraceable)]
@@ -148,7 +148,7 @@ impl HTMLCollection {
             ascii_lower_qualified_name: qualified_name.to_ascii_lowercase(),
             qualified_name: qualified_name,
         };
-        HTMLCollection::create(window, root, box filter)
+        HTMLCollection::create(window, root, Box::new(filter))
     }
 
     fn match_element(elem: &Element, qualified_name: &LocalName) -> bool {
@@ -182,7 +182,7 @@ impl HTMLCollection {
         let filter = TagNameNSFilter {
             qname: qname
         };
-        HTMLCollection::create(window, root, box filter)
+        HTMLCollection::create(window, root, Box::new(filter))
     }
 
     pub fn by_class_name(window: &Window, root: &Node, classes: DOMString)
@@ -208,7 +208,7 @@ impl HTMLCollection {
         let filter = ClassNameFilter {
             classes: classes
         };
-        HTMLCollection::create(window, root, box filter)
+        HTMLCollection::create(window, root, Box::new(filter))
     }
 
     pub fn children(window: &Window, root: &Node) -> DomRoot<HTMLCollection> {
@@ -219,7 +219,7 @@ impl HTMLCollection {
                 root.is_parent_of(elem.upcast())
             }
         }
-        HTMLCollection::create(window, root, box ElementChildFilter)
+        HTMLCollection::create(window, root, Box::new(ElementChildFilter))
     }
 
     pub fn elements_iter_after<'a>(&'a self, after: &'a Node) -> impl Iterator<Item=DomRoot<Element>> + 'a {
diff --git a/servo/components/script/dom/htmldataelement.rs b/servo/components/script/dom/htmldataelement.rs
index 556fec894e28..98aa078993c8 100644
--- a/servo/components/script/dom/htmldataelement.rs
+++ b/servo/components/script/dom/htmldataelement.rs
@@ -30,7 +30,7 @@ impl HTMLDataElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLDataElement> {
-        Node::reflect_node(box HTMLDataElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLDataElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLDataElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmldatalistelement.rs b/servo/components/script/dom/htmldatalistelement.rs
index 1e71ca7502b3..2352fa99bcf1 100644
--- a/servo/components/script/dom/htmldatalistelement.rs
+++ b/servo/components/script/dom/htmldatalistelement.rs
@@ -34,7 +34,7 @@ impl HTMLDataListElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLDataListElement> {
-        Node::reflect_node(box HTMLDataListElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLDataListElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLDataListElementBinding::Wrap)
     }
@@ -50,7 +50,7 @@ impl HTMLDataListElementMethods for HTMLDataListElement {
                 elem.is::<HTMLOptionElement>()
             }
         }
-        let filter = box HTMLDataListOptionsFilter;
+        let filter = Box::new(HTMLDataListOptionsFilter);
         let window = window_from_node(self);
         HTMLCollection::create(&window, self.upcast(), filter)
     }
diff --git a/servo/components/script/dom/htmldetailselement.rs b/servo/components/script/dom/htmldetailselement.rs
index 75780f83d86b..61ef9b4a0d06 100644
--- a/servo/components/script/dom/htmldetailselement.rs
+++ b/servo/components/script/dom/htmldetailselement.rs
@@ -40,7 +40,7 @@ impl HTMLDetailsElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLDetailsElement> {
-        Node::reflect_node(box HTMLDetailsElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLDetailsElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLDetailsElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmldialogelement.rs b/servo/components/script/dom/htmldialogelement.rs
index 39e195e08145..9762a6c3c976 100644
--- a/servo/components/script/dom/htmldialogelement.rs
+++ b/servo/components/script/dom/htmldialogelement.rs
@@ -37,7 +37,7 @@ impl HTMLDialogElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLDialogElement> {
-        Node::reflect_node(box HTMLDialogElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLDialogElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLDialogElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmldirectoryelement.rs b/servo/components/script/dom/htmldirectoryelement.rs
index 2ec56cb6415d..1665202b4ec0 100644
--- a/servo/components/script/dom/htmldirectoryelement.rs
+++ b/servo/components/script/dom/htmldirectoryelement.rs
@@ -29,7 +29,7 @@ impl HTMLDirectoryElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLDirectoryElement> {
-        Node::reflect_node(box HTMLDirectoryElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLDirectoryElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLDirectoryElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmldivelement.rs b/servo/components/script/dom/htmldivelement.rs
index 001ca7c5ca5e..48fd3afb9518 100644
--- a/servo/components/script/dom/htmldivelement.rs
+++ b/servo/components/script/dom/htmldivelement.rs
@@ -29,7 +29,7 @@ impl HTMLDivElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLDivElement> {
-        Node::reflect_node(box HTMLDivElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLDivElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLDivElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmldlistelement.rs b/servo/components/script/dom/htmldlistelement.rs
index 6622571c5c89..5ad4e8f27f70 100644
--- a/servo/components/script/dom/htmldlistelement.rs
+++ b/servo/components/script/dom/htmldlistelement.rs
@@ -27,7 +27,7 @@ impl HTMLDListElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLDListElement> {
-        Node::reflect_node(box HTMLDListElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLDListElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLDListElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlelement.rs b/servo/components/script/dom/htmlelement.rs
index 87d362dfab82..f88e26a22e5f 100644
--- a/servo/components/script/dom/htmlelement.rs
+++ b/servo/components/script/dom/htmlelement.rs
@@ -62,7 +62,7 @@ impl HTMLElement {
 
     #[allow(unrooted_must_root)]
     pub fn new(local_name: LocalName, prefix: Option<Prefix>, document: &Document) -> DomRoot<HTMLElement> {
-        Node::reflect_node(box HTMLElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlembedelement.rs b/servo/components/script/dom/htmlembedelement.rs
index daa011fcf6d9..cf4039f5515f 100644
--- a/servo/components/script/dom/htmlembedelement.rs
+++ b/servo/components/script/dom/htmlembedelement.rs
@@ -26,7 +26,7 @@ impl HTMLEmbedElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLEmbedElement> {
-        Node::reflect_node(box HTMLEmbedElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLEmbedElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLEmbedElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlfieldsetelement.rs b/servo/components/script/dom/htmlfieldsetelement.rs
index 89e1d2db481e..bee8a41d4cda 100644
--- a/servo/components/script/dom/htmlfieldsetelement.rs
+++ b/servo/components/script/dom/htmlfieldsetelement.rs
@@ -43,7 +43,7 @@ impl HTMLFieldSetElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLFieldSetElement> {
-        Node::reflect_node(box HTMLFieldSetElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLFieldSetElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLFieldSetElementBinding::Wrap)
     }
@@ -60,7 +60,7 @@ impl HTMLFieldSetElementMethods for HTMLFieldSetElement {
                     .map_or(false, HTMLElement::is_listed_element)
             }
         }
-        let filter = box ElementsFilter;
+        let filter = Box::new(ElementsFilter);
         let window = window_from_node(self);
         HTMLCollection::create(&window, self.upcast(), filter)
     }
diff --git a/servo/components/script/dom/htmlfontelement.rs b/servo/components/script/dom/htmlfontelement.rs
index c5eee1971598..fa3fcd2424ce 100644
--- a/servo/components/script/dom/htmlfontelement.rs
+++ b/servo/components/script/dom/htmlfontelement.rs
@@ -37,7 +37,7 @@ impl HTMLFontElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLFontElement> {
-        Node::reflect_node(box HTMLFontElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLFontElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLFontElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlformcontrolscollection.rs b/servo/components/script/dom/htmlformcontrolscollection.rs
index 8b786d2cb357..76398666f0f1 100644
--- a/servo/components/script/dom/htmlformcontrolscollection.rs
+++ b/servo/components/script/dom/htmlformcontrolscollection.rs
@@ -32,7 +32,7 @@ impl HTMLFormControlsCollection {
     pub fn new(window: &Window, root: &Node, filter: Box<CollectionFilter + 'static>)
         -> DomRoot<HTMLFormControlsCollection>
     {
-        reflect_dom_object(box HTMLFormControlsCollection::new_inherited(root, filter),
+        reflect_dom_object(Box::new(HTMLFormControlsCollection::new_inherited(root, filter)),
                            window,
                            HTMLFormControlsCollectionBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlformelement.rs b/servo/components/script/dom/htmlformelement.rs
index b58194bed62c..d1731e6f2ff7 100755
--- a/servo/components/script/dom/htmlformelement.rs
+++ b/servo/components/script/dom/htmlformelement.rs
@@ -86,7 +86,7 @@ impl HTMLFormElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLFormElement> {
-        Node::reflect_node(box HTMLFormElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLFormElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLFormElementBinding::Wrap)
     }
@@ -217,7 +217,7 @@ impl HTMLFormElementMethods for HTMLFormElement {
             }
         }
         DomRoot::from_ref(self.elements.init_once(|| {
-            let filter = box ElementsFilter { form: DomRoot::from_ref(self) };
+            let filter = Box::new(ElementsFilter { form: DomRoot::from_ref(self) });
             let window = window_from_node(self);
             HTMLFormControlsCollection::new(&window, self.upcast(), filter)
         }))
diff --git a/servo/components/script/dom/htmlframeelement.rs b/servo/components/script/dom/htmlframeelement.rs
index 147e05a836eb..c7e282ca4a59 100644
--- a/servo/components/script/dom/htmlframeelement.rs
+++ b/servo/components/script/dom/htmlframeelement.rs
@@ -26,7 +26,7 @@ impl HTMLFrameElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLFrameElement> {
-        Node::reflect_node(box HTMLFrameElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLFrameElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLFrameElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlframesetelement.rs b/servo/components/script/dom/htmlframesetelement.rs
index 99b58deea3d3..909ab214ade8 100644
--- a/servo/components/script/dom/htmlframesetelement.rs
+++ b/servo/components/script/dom/htmlframesetelement.rs
@@ -31,7 +31,7 @@ impl HTMLFrameSetElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLFrameSetElement> {
-        Node::reflect_node(box HTMLFrameSetElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLFrameSetElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLFrameSetElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlheadelement.rs b/servo/components/script/dom/htmlheadelement.rs
index 1aaf0a799b59..5d9cb05eddf4 100644
--- a/servo/components/script/dom/htmlheadelement.rs
+++ b/servo/components/script/dom/htmlheadelement.rs
@@ -34,7 +34,7 @@ impl HTMLHeadElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLHeadElement> {
-        Node::reflect_node(box HTMLHeadElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLHeadElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLHeadElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlheadingelement.rs b/servo/components/script/dom/htmlheadingelement.rs
index 44223863dd48..8420def4a84d 100644
--- a/servo/components/script/dom/htmlheadingelement.rs
+++ b/servo/components/script/dom/htmlheadingelement.rs
@@ -43,7 +43,7 @@ impl HTMLHeadingElement {
                prefix: Option<Prefix>,
                document: &Document,
                level: HeadingLevel) -> DomRoot<HTMLHeadingElement> {
-        Node::reflect_node(box HTMLHeadingElement::new_inherited(local_name, prefix, document, level),
+        Node::reflect_node(Box::new(HTMLHeadingElement::new_inherited(local_name, prefix, document, level)),
                            document,
                            HTMLHeadingElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlhrelement.rs b/servo/components/script/dom/htmlhrelement.rs
index e4769ed72024..740bbd9aac2b 100644
--- a/servo/components/script/dom/htmlhrelement.rs
+++ b/servo/components/script/dom/htmlhrelement.rs
@@ -32,7 +32,7 @@ impl HTMLHRElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLHRElement> {
-        Node::reflect_node(box HTMLHRElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLHRElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLHRElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlhtmlelement.rs b/servo/components/script/dom/htmlhtmlelement.rs
index b112e304c09c..c5eb4e1fca56 100644
--- a/servo/components/script/dom/htmlhtmlelement.rs
+++ b/servo/components/script/dom/htmlhtmlelement.rs
@@ -26,7 +26,7 @@ impl HTMLHtmlElement {
     pub fn new(localName: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLHtmlElement> {
-        Node::reflect_node(box HTMLHtmlElement::new_inherited(localName, prefix, document),
+        Node::reflect_node(Box::new(HTMLHtmlElement::new_inherited(localName, prefix, document)),
                            document,
                            HTMLHtmlElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmliframeelement.rs b/servo/components/script/dom/htmliframeelement.rs
index 61828e4b4045..8ed40cb3c1d1 100644
--- a/servo/components/script/dom/htmliframeelement.rs
+++ b/servo/components/script/dom/htmliframeelement.rs
@@ -335,7 +335,7 @@ impl HTMLIFrameElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLIFrameElement> {
-        Node::reflect_node(box HTMLIFrameElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLIFrameElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLIFrameElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlimageelement.rs b/servo/components/script/dom/htmlimageelement.rs
index 1eb019563501..95aa1288fe29 100644
--- a/servo/components/script/dom/htmlimageelement.rs
+++ b/servo/components/script/dom/htmlimageelement.rs
@@ -200,7 +200,7 @@ impl HTMLImageElement {
             let task_source = window.networking_task_source();
             let task_canceller = window.task_canceller();
             let generation = elem.generation.get();
-            ROUTER.add_route(responder_receiver.to_opaque(), box move |message| {
+            ROUTER.add_route(responder_receiver.to_opaque(), Box::new(move |message| {
                 debug!("Got image {:?}", message);
                 // Return the image via a message to the script thread, which marks
                 // the element as dirty and triggers a reflow.
@@ -217,7 +217,7 @@ impl HTMLImageElement {
                     }),
                     &task_canceller,
                 );
-            });
+            }));
 
             image_cache.add_listener(id, ImageResponder::new(responder_sender, id));
         }
@@ -268,9 +268,9 @@ impl HTMLImageElement {
             task_source: window.networking_task_source(),
             canceller: Some(window.task_canceller()),
         };
-        ROUTER.add_route(action_receiver.to_opaque(), box move |message| {
+        ROUTER.add_route(action_receiver.to_opaque(), Box::new(move |message| {
             listener.notify_fetch(message.to().unwrap());
-        });
+        }));
 
         let request = RequestInit {
             url: img_url.clone(),
@@ -640,7 +640,7 @@ impl HTMLImageElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLImageElement> {
-        Node::reflect_node(box HTMLImageElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLImageElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLImageElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlinputelement.rs b/servo/components/script/dom/htmlinputelement.rs
index 08ea8a576534..690c2899d3e4 100755
--- a/servo/components/script/dom/htmlinputelement.rs
+++ b/servo/components/script/dom/htmlinputelement.rs
@@ -165,7 +165,7 @@ impl HTMLInputElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLInputElement> {
-        Node::reflect_node(box HTMLInputElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLInputElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLInputElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmllabelelement.rs b/servo/components/script/dom/htmllabelelement.rs
index 09397059eabc..4e5658169894 100644
--- a/servo/components/script/dom/htmllabelelement.rs
+++ b/servo/components/script/dom/htmllabelelement.rs
@@ -40,7 +40,7 @@ impl HTMLLabelElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLLabelElement> {
-        Node::reflect_node(box HTMLLabelElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLLabelElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLLabelElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmllegendelement.rs b/servo/components/script/dom/htmllegendelement.rs
index c54b25f61182..58c193fd6d5e 100644
--- a/servo/components/script/dom/htmllegendelement.rs
+++ b/servo/components/script/dom/htmllegendelement.rs
@@ -39,7 +39,7 @@ impl HTMLLegendElement {
                prefix: Option<Prefix>,
                document: &Document)
                -> DomRoot<HTMLLegendElement> {
-        Node::reflect_node(box HTMLLegendElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLLegendElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLLegendElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmllielement.rs b/servo/components/script/dom/htmllielement.rs
index da98a3d1be29..81b6c4ff6a15 100644
--- a/servo/components/script/dom/htmllielement.rs
+++ b/servo/components/script/dom/htmllielement.rs
@@ -31,7 +31,7 @@ impl HTMLLIElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLLIElement> {
-        Node::reflect_node(box HTMLLIElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLLIElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLLIElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmllinkelement.rs b/servo/components/script/dom/htmllinkelement.rs
index 320b425331b2..db220dda1949 100644
--- a/servo/components/script/dom/htmllinkelement.rs
+++ b/servo/components/script/dom/htmllinkelement.rs
@@ -86,7 +86,7 @@ impl HTMLLinkElement {
                prefix: Option<Prefix>,
                document: &Document,
                creator: ElementCreator) -> DomRoot<HTMLLinkElement> {
-        Node::reflect_node(box HTMLLinkElement::new_inherited(local_name, prefix, document, creator),
+        Node::reflect_node(Box::new(HTMLLinkElement::new_inherited(local_name, prefix, document, creator)),
                            document,
                            HTMLLinkElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlmapelement.rs b/servo/components/script/dom/htmlmapelement.rs
index 82afa2c121fe..0648c2b3c7b3 100644
--- a/servo/components/script/dom/htmlmapelement.rs
+++ b/servo/components/script/dom/htmlmapelement.rs
@@ -30,7 +30,7 @@ impl HTMLMapElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLMapElement> {
-        Node::reflect_node(box HTMLMapElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLMapElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLMapElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlmediaelement.rs b/servo/components/script/dom/htmlmediaelement.rs
index d5c3748bd0cd..197a7b1a5e8d 100644
--- a/servo/components/script/dom/htmlmediaelement.rs
+++ b/servo/components/script/dom/htmlmediaelement.rs
@@ -611,9 +611,9 @@ impl HTMLMediaElement {
                     task_source: window.networking_task_source(),
                     canceller: Some(window.task_canceller())
                 };
-                ROUTER.add_route(action_receiver.to_opaque(), box move |message| {
+                ROUTER.add_route(action_receiver.to_opaque(), Box::new(move |message| {
                     listener.notify_fetch(message.to().unwrap());
-                });
+                }));
                 document.loader().fetch_async_background(request, action_sender);
             },
             Resource::Object => {
diff --git a/servo/components/script/dom/htmlmetaelement.rs b/servo/components/script/dom/htmlmetaelement.rs
index 36a2f7016430..c843272eaab4 100644
--- a/servo/components/script/dom/htmlmetaelement.rs
+++ b/servo/components/script/dom/htmlmetaelement.rs
@@ -52,7 +52,7 @@ impl HTMLMetaElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLMetaElement> {
-        Node::reflect_node(box HTMLMetaElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLMetaElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLMetaElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlmeterelement.rs b/servo/components/script/dom/htmlmeterelement.rs
index 2fd7a554fce3..eee3c92b6577 100644
--- a/servo/components/script/dom/htmlmeterelement.rs
+++ b/servo/components/script/dom/htmlmeterelement.rs
@@ -30,7 +30,7 @@ impl HTMLMeterElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLMeterElement> {
-        Node::reflect_node(box HTMLMeterElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLMeterElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLMeterElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlmodelement.rs b/servo/components/script/dom/htmlmodelement.rs
index 4266b954a81e..e749bea706f4 100644
--- a/servo/components/script/dom/htmlmodelement.rs
+++ b/servo/components/script/dom/htmlmodelement.rs
@@ -29,7 +29,7 @@ impl HTMLModElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLModElement> {
-        Node::reflect_node(box HTMLModElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLModElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLModElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlobjectelement.rs b/servo/components/script/dom/htmlobjectelement.rs
index 0cde28ec1a6f..ce45e089fdcb 100755
--- a/servo/components/script/dom/htmlobjectelement.rs
+++ b/servo/components/script/dom/htmlobjectelement.rs
@@ -47,7 +47,7 @@ impl HTMLObjectElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLObjectElement> {
-        Node::reflect_node(box HTMLObjectElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLObjectElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLObjectElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlolistelement.rs b/servo/components/script/dom/htmlolistelement.rs
index 58c159f1e686..8de9a8595e14 100644
--- a/servo/components/script/dom/htmlolistelement.rs
+++ b/servo/components/script/dom/htmlolistelement.rs
@@ -28,7 +28,7 @@ impl HTMLOListElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLOListElement> {
-        Node::reflect_node(box HTMLOListElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLOListElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLOListElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmloptgroupelement.rs b/servo/components/script/dom/htmloptgroupelement.rs
index b22bb0a79b57..88e2d3012df6 100644
--- a/servo/components/script/dom/htmloptgroupelement.rs
+++ b/servo/components/script/dom/htmloptgroupelement.rs
@@ -37,7 +37,7 @@ impl HTMLOptGroupElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLOptGroupElement> {
-        Node::reflect_node(box HTMLOptGroupElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLOptGroupElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLOptGroupElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmloptionelement.rs b/servo/components/script/dom/htmloptionelement.rs
index 9e916912b871..e8449f03f1b5 100644
--- a/servo/components/script/dom/htmloptionelement.rs
+++ b/servo/components/script/dom/htmloptionelement.rs
@@ -56,7 +56,7 @@ impl HTMLOptionElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLOptionElement> {
-        Node::reflect_node(box HTMLOptionElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLOptionElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLOptionElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmloptionscollection.rs b/servo/components/script/dom/htmloptionscollection.rs
index 84d4901aa8b6..98c0440d43ae 100644
--- a/servo/components/script/dom/htmloptionscollection.rs
+++ b/servo/components/script/dom/htmloptionscollection.rs
@@ -37,7 +37,7 @@ impl HTMLOptionsCollection {
     pub fn new(window: &Window, select: &HTMLSelectElement, filter: Box<CollectionFilter + 'static>)
         -> DomRoot<HTMLOptionsCollection>
     {
-        reflect_dom_object(box HTMLOptionsCollection::new_inherited(select, filter),
+        reflect_dom_object(Box::new(HTMLOptionsCollection::new_inherited(select, filter)),
                            window,
                            HTMLOptionsCollectionBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmloutputelement.rs b/servo/components/script/dom/htmloutputelement.rs
index d3d7d5991cff..e9706684e684 100644
--- a/servo/components/script/dom/htmloutputelement.rs
+++ b/servo/components/script/dom/htmloutputelement.rs
@@ -39,7 +39,7 @@ impl HTMLOutputElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLOutputElement> {
-        Node::reflect_node(box HTMLOutputElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLOutputElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLOutputElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlparagraphelement.rs b/servo/components/script/dom/htmlparagraphelement.rs
index f17b7653b6ff..bcebc146daf3 100644
--- a/servo/components/script/dom/htmlparagraphelement.rs
+++ b/servo/components/script/dom/htmlparagraphelement.rs
@@ -29,7 +29,7 @@ impl HTMLParagraphElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLParagraphElement> {
-        Node::reflect_node(box HTMLParagraphElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLParagraphElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLParagraphElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlparamelement.rs b/servo/components/script/dom/htmlparamelement.rs
index a1544b8157c3..3cad6ef80e51 100644
--- a/servo/components/script/dom/htmlparamelement.rs
+++ b/servo/components/script/dom/htmlparamelement.rs
@@ -29,7 +29,7 @@ impl HTMLParamElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLParamElement> {
-        Node::reflect_node(box HTMLParamElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLParamElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLParamElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlpreelement.rs b/servo/components/script/dom/htmlpreelement.rs
index 7befed936cc8..5519196020da 100644
--- a/servo/components/script/dom/htmlpreelement.rs
+++ b/servo/components/script/dom/htmlpreelement.rs
@@ -29,7 +29,7 @@ impl HTMLPreElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLPreElement> {
-        Node::reflect_node(box HTMLPreElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLPreElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLPreElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlprogresselement.rs b/servo/components/script/dom/htmlprogresselement.rs
index c8fb1937fe16..b8f4dbd6970b 100644
--- a/servo/components/script/dom/htmlprogresselement.rs
+++ b/servo/components/script/dom/htmlprogresselement.rs
@@ -31,7 +31,7 @@ impl HTMLProgressElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLProgressElement> {
-        Node::reflect_node(box HTMLProgressElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLProgressElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLProgressElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlquoteelement.rs b/servo/components/script/dom/htmlquoteelement.rs
index 9db0dbc87f32..0d03a69848a4 100644
--- a/servo/components/script/dom/htmlquoteelement.rs
+++ b/servo/components/script/dom/htmlquoteelement.rs
@@ -29,7 +29,7 @@ impl HTMLQuoteElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLQuoteElement> {
-        Node::reflect_node(box HTMLQuoteElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLQuoteElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLQuoteElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlscriptelement.rs b/servo/components/script/dom/htmlscriptelement.rs
index 5c85aa308993..1108f8438f8c 100644
--- a/servo/components/script/dom/htmlscriptelement.rs
+++ b/servo/components/script/dom/htmlscriptelement.rs
@@ -84,7 +84,7 @@ impl HTMLScriptElement {
     #[allow(unrooted_must_root)]
     pub fn new(local_name: LocalName, prefix: Option<Prefix>, document: &Document,
                creator: ElementCreator) -> DomRoot<HTMLScriptElement> {
-        Node::reflect_node(box HTMLScriptElement::new_inherited(local_name, prefix, document, creator),
+        Node::reflect_node(Box::new(HTMLScriptElement::new_inherited(local_name, prefix, document, creator)),
                            document,
                            HTMLScriptElementBinding::Wrap)
     }
@@ -279,9 +279,9 @@ fn fetch_a_classic_script(script: &HTMLScriptElement,
         canceller: Some(doc.window().task_canceller())
     };
 
-    ROUTER.add_route(action_receiver.to_opaque(), box move |message| {
+    ROUTER.add_route(action_receiver.to_opaque(), Box::new(move |message| {
         listener.notify_fetch(message.to().unwrap());
-    });
+    }));
     doc.fetch_async(LoadType::Script(url), request, action_sender);
 }
 
diff --git a/servo/components/script/dom/htmlselectelement.rs b/servo/components/script/dom/htmlselectelement.rs
index d9eba4dea723..75dea8d461e7 100755
--- a/servo/components/script/dom/htmlselectelement.rs
+++ b/servo/components/script/dom/htmlselectelement.rs
@@ -84,7 +84,7 @@ impl HTMLSelectElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLSelectElement> {
-        Node::reflect_node(box HTMLSelectElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLSelectElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLSelectElementBinding::Wrap)
     }
@@ -247,7 +247,7 @@ impl HTMLSelectElementMethods for HTMLSelectElement {
         self.options.or_init(|| {
             let window = window_from_node(self);
             HTMLOptionsCollection::new(
-                &window, self, box OptionsFilter)
+                &window, self, Box::new(OptionsFilter))
         })
     }
 
diff --git a/servo/components/script/dom/htmlsourceelement.rs b/servo/components/script/dom/htmlsourceelement.rs
index c7a60c159c86..a81fcfbf80b9 100644
--- a/servo/components/script/dom/htmlsourceelement.rs
+++ b/servo/components/script/dom/htmlsourceelement.rs
@@ -33,7 +33,7 @@ impl HTMLSourceElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLSourceElement> {
-        Node::reflect_node(box HTMLSourceElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLSourceElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLSourceElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlspanelement.rs b/servo/components/script/dom/htmlspanelement.rs
index f0a16e47d612..9e3448662d0b 100644
--- a/servo/components/script/dom/htmlspanelement.rs
+++ b/servo/components/script/dom/htmlspanelement.rs
@@ -26,7 +26,7 @@ impl HTMLSpanElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLSpanElement> {
-        Node::reflect_node(box HTMLSpanElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLSpanElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLSpanElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlstyleelement.rs b/servo/components/script/dom/htmlstyleelement.rs
index 952c143ad688..79930c2c551f 100644
--- a/servo/components/script/dom/htmlstyleelement.rs
+++ b/servo/components/script/dom/htmlstyleelement.rs
@@ -64,7 +64,7 @@ impl HTMLStyleElement {
                prefix: Option<Prefix>,
                document: &Document,
                creator: ElementCreator) -> DomRoot<HTMLStyleElement> {
-        Node::reflect_node(box HTMLStyleElement::new_inherited(local_name, prefix, document, creator),
+        Node::reflect_node(Box::new(HTMLStyleElement::new_inherited(local_name, prefix, document, creator)),
                            document,
                            HTMLStyleElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmltablecaptionelement.rs b/servo/components/script/dom/htmltablecaptionelement.rs
index 2ceecc50609e..a993d03a9900 100644
--- a/servo/components/script/dom/htmltablecaptionelement.rs
+++ b/servo/components/script/dom/htmltablecaptionelement.rs
@@ -29,7 +29,7 @@ impl HTMLTableCaptionElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLTableCaptionElement> {
-        Node::reflect_node(box HTMLTableCaptionElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLTableCaptionElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLTableCaptionElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmltablecolelement.rs b/servo/components/script/dom/htmltablecolelement.rs
index ffbef21ed897..71e3177554f3 100644
--- a/servo/components/script/dom/htmltablecolelement.rs
+++ b/servo/components/script/dom/htmltablecolelement.rs
@@ -29,7 +29,7 @@ impl HTMLTableColElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLTableColElement> {
-        Node::reflect_node(box HTMLTableColElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLTableColElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLTableColElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmltabledatacellelement.rs b/servo/components/script/dom/htmltabledatacellelement.rs
index 7ebd64f20dc0..ba885952fe76 100644
--- a/servo/components/script/dom/htmltabledatacellelement.rs
+++ b/servo/components/script/dom/htmltabledatacellelement.rs
@@ -28,10 +28,12 @@ impl HTMLTableDataCellElement {
     #[allow(unrooted_must_root)]
     pub fn new(local_name: LocalName, prefix: Option<Prefix>, document: &Document)
                -> DomRoot<HTMLTableDataCellElement> {
-        Node::reflect_node(box HTMLTableDataCellElement::new_inherited(local_name,
-                                                                       prefix,
-                                                                       document),
-                           document,
-                           HTMLTableDataCellElementBinding::Wrap)
+        Node::reflect_node(
+            Box::new(HTMLTableDataCellElement::new_inherited(
+                local_name, prefix, document
+            )),
+            document,
+            HTMLTableDataCellElementBinding::Wrap
+        )
     }
 }
diff --git a/servo/components/script/dom/htmltableelement.rs b/servo/components/script/dom/htmltableelement.rs
index 2f8e3e3857b2..cda13a6496d2 100644
--- a/servo/components/script/dom/htmltableelement.rs
+++ b/servo/components/script/dom/htmltableelement.rs
@@ -63,7 +63,7 @@ impl HTMLTableElement {
     #[allow(unrooted_must_root)]
     pub fn new(local_name: LocalName, prefix: Option<Prefix>, document: &Document)
                -> DomRoot<HTMLTableElement> {
-        Node::reflect_node(box HTMLTableElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLTableElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLTableElementBinding::Wrap)
     }
@@ -151,7 +151,7 @@ impl HTMLTableElementMethods for HTMLTableElement {
     // https://html.spec.whatwg.org/multipage/#dom-table-rows
     fn Rows(&self) -> DomRoot<HTMLCollection> {
         let filter = self.get_rows();
-        HTMLCollection::new(&window_from_node(self), self.upcast(), box filter)
+        HTMLCollection::new(&window_from_node(self), self.upcast(), Box::new(filter))
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-table-caption
@@ -264,7 +264,7 @@ impl HTMLTableElementMethods for HTMLTableElement {
 
         self.tbodies.or_init(|| {
             let window = window_from_node(self);
-            let filter = box TBodiesFilter;
+            let filter = Box::new(TBodiesFilter);
             HTMLCollection::create(&window, self.upcast(), filter)
         })
     }
diff --git a/servo/components/script/dom/htmltableheadercellelement.rs b/servo/components/script/dom/htmltableheadercellelement.rs
index 6b03b4211171..db7e6ee368c7 100644
--- a/servo/components/script/dom/htmltableheadercellelement.rs
+++ b/servo/components/script/dom/htmltableheadercellelement.rs
@@ -29,7 +29,7 @@ impl HTMLTableHeaderCellElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLTableHeaderCellElement> {
-        Node::reflect_node(box HTMLTableHeaderCellElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLTableHeaderCellElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLTableHeaderCellElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmltablerowelement.rs b/servo/components/script/dom/htmltablerowelement.rs
index bdc6708ee4f2..6e8802c29372 100644
--- a/servo/components/script/dom/htmltablerowelement.rs
+++ b/servo/components/script/dom/htmltablerowelement.rs
@@ -52,7 +52,7 @@ impl HTMLTableRowElement {
     #[allow(unrooted_must_root)]
     pub fn new(local_name: LocalName, prefix: Option<Prefix>, document: &Document)
                -> DomRoot<HTMLTableRowElement> {
-        Node::reflect_node(box HTMLTableRowElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLTableRowElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLTableRowElementBinding::Wrap)
     }
@@ -77,7 +77,7 @@ impl HTMLTableRowElementMethods for HTMLTableRowElement {
     fn Cells(&self) -> DomRoot<HTMLCollection> {
         self.cells.or_init(|| {
             let window = window_from_node(self);
-            let filter = box CellsFilter;
+            let filter = Box::new(CellsFilter);
             HTMLCollection::create(&window, self.upcast(), filter)
         })
     }
diff --git a/servo/components/script/dom/htmltablesectionelement.rs b/servo/components/script/dom/htmltablesectionelement.rs
index 1b4d1c72020d..58c72ddeed5e 100644
--- a/servo/components/script/dom/htmltablesectionelement.rs
+++ b/servo/components/script/dom/htmltablesectionelement.rs
@@ -36,7 +36,7 @@ impl HTMLTableSectionElement {
     #[allow(unrooted_must_root)]
     pub fn new(local_name: LocalName, prefix: Option<Prefix>, document: &Document)
                -> DomRoot<HTMLTableSectionElement> {
-        Node::reflect_node(box HTMLTableSectionElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLTableSectionElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLTableSectionElementBinding::Wrap)
     }
@@ -54,7 +54,7 @@ impl CollectionFilter for RowsFilter {
 impl HTMLTableSectionElementMethods for HTMLTableSectionElement {
     // https://html.spec.whatwg.org/multipage/#dom-tbody-rows
     fn Rows(&self) -> DomRoot<HTMLCollection> {
-        HTMLCollection::create(&window_from_node(self), self.upcast(), box RowsFilter)
+        HTMLCollection::create(&window_from_node(self), self.upcast(), Box::new(RowsFilter))
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-tbody-insertrow
diff --git a/servo/components/script/dom/htmltemplateelement.rs b/servo/components/script/dom/htmltemplateelement.rs
index dde9d380c728..b8a8e5b3ac0e 100644
--- a/servo/components/script/dom/htmltemplateelement.rs
+++ b/servo/components/script/dom/htmltemplateelement.rs
@@ -39,7 +39,7 @@ impl HTMLTemplateElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLTemplateElement> {
-        Node::reflect_node(box HTMLTemplateElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLTemplateElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLTemplateElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmltextareaelement.rs b/servo/components/script/dom/htmltextareaelement.rs
index c599113f6b39..0825bb70302a 100755
--- a/servo/components/script/dom/htmltextareaelement.rs
+++ b/servo/components/script/dom/htmltextareaelement.rs
@@ -125,7 +125,7 @@ impl HTMLTextAreaElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLTextAreaElement> {
-        Node::reflect_node(box HTMLTextAreaElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLTextAreaElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLTextAreaElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmltimeelement.rs b/servo/components/script/dom/htmltimeelement.rs
index 0653d32ad5fe..bc477d99ed66 100644
--- a/servo/components/script/dom/htmltimeelement.rs
+++ b/servo/components/script/dom/htmltimeelement.rs
@@ -28,7 +28,7 @@ impl HTMLTimeElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLTimeElement> {
-        Node::reflect_node(box HTMLTimeElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLTimeElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLTimeElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmltitleelement.rs b/servo/components/script/dom/htmltitleelement.rs
index 0c1aeac47b60..986feac95a8b 100644
--- a/servo/components/script/dom/htmltitleelement.rs
+++ b/servo/components/script/dom/htmltitleelement.rs
@@ -31,7 +31,7 @@ impl HTMLTitleElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLTitleElement> {
-        Node::reflect_node(box HTMLTitleElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLTitleElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLTitleElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmltrackelement.rs b/servo/components/script/dom/htmltrackelement.rs
index 94015862c58b..7b6eb23cf1e6 100644
--- a/servo/components/script/dom/htmltrackelement.rs
+++ b/servo/components/script/dom/htmltrackelement.rs
@@ -26,7 +26,7 @@ impl HTMLTrackElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLTrackElement> {
-        Node::reflect_node(box HTMLTrackElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLTrackElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLTrackElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlulistelement.rs b/servo/components/script/dom/htmlulistelement.rs
index d6b1b7ea41e1..b2338cae8865 100644
--- a/servo/components/script/dom/htmlulistelement.rs
+++ b/servo/components/script/dom/htmlulistelement.rs
@@ -26,7 +26,7 @@ impl HTMLUListElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLUListElement> {
-        Node::reflect_node(box HTMLUListElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLUListElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLUListElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlunknownelement.rs b/servo/components/script/dom/htmlunknownelement.rs
index 1622b88cb777..0897171442a4 100644
--- a/servo/components/script/dom/htmlunknownelement.rs
+++ b/servo/components/script/dom/htmlunknownelement.rs
@@ -29,7 +29,7 @@ impl HTMLUnknownElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLUnknownElement> {
-        Node::reflect_node(box HTMLUnknownElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLUnknownElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLUnknownElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/htmlvideoelement.rs b/servo/components/script/dom/htmlvideoelement.rs
index 998f46c279bc..f1f556f1bb42 100644
--- a/servo/components/script/dom/htmlvideoelement.rs
+++ b/servo/components/script/dom/htmlvideoelement.rs
@@ -27,7 +27,7 @@ impl HTMLVideoElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<HTMLVideoElement> {
-        Node::reflect_node(box HTMLVideoElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(HTMLVideoElement::new_inherited(local_name, prefix, document)),
                            document,
                            HTMLVideoElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/imagedata.rs b/servo/components/script/dom/imagedata.rs
index 98be416ff457..f0270fbe7b7d 100644
--- a/servo/components/script/dom/imagedata.rs
+++ b/servo/components/script/dom/imagedata.rs
@@ -2,10 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use core::nonzero::NonZero;
 use dom::bindings::codegen::Bindings::ImageDataBinding;
 use dom::bindings::codegen::Bindings::ImageDataBinding::ImageDataMethods;
 use dom::bindings::error::{Fallible, Error};
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
 use dom::globalscope::GlobalScope;
@@ -91,12 +91,12 @@ impl ImageData {
             return Err(Error::IndexSize);
         }
 
-        let imagedata = box ImageData {
+        let imagedata = Box::new(ImageData {
             reflector_: Reflector::new(),
             width: width,
             height: height,
             data: Heap::default(),
-        };
+        });
 
         if let Some(jsobject) = opt_jsobject {
             (*imagedata).data.set(jsobject);
@@ -159,8 +159,8 @@ impl ImageDataMethods for ImageData {
 
     #[allow(unsafe_code)]
     // https://html.spec.whatwg.org/multipage/#dom-imagedata-data
-    unsafe fn Data(&self, _: *mut JSContext) -> NonZero<*mut JSObject> {
+    unsafe fn Data(&self, _: *mut JSContext) -> NonNullJSObjectPtr {
         assert!(!self.data.get().is_null());
-        NonZero::new_unchecked(self.data.get())
+        NonNullJSObjectPtr::new_unchecked(self.data.get())
     }
 }
diff --git a/servo/components/script/dom/inputevent.rs b/servo/components/script/dom/inputevent.rs
index 641eb21a5d30..3d855d08b414 100644
--- a/servo/components/script/dom/inputevent.rs
+++ b/servo/components/script/dom/inputevent.rs
@@ -28,11 +28,11 @@ impl InputEvent {
                detail: i32,
                data: Option<DOMString>,
                is_composing: bool) -> DomRoot<InputEvent> {
-        let ev = reflect_dom_object(box InputEvent {
+        let ev = reflect_dom_object(Box::new(InputEvent {
                                         uievent: UIEvent::new_inherited(),
                                         data: data,
                                         is_composing: is_composing,
-                                    },
+                                    }),
                                     window,
                                     InputEventBinding::Wrap);
         ev.uievent.InitUIEvent(type_, can_bubble, cancelable, view, detail);
diff --git a/servo/components/script/dom/keyboardevent.rs b/servo/components/script/dom/keyboardevent.rs
index 69d71ae665af..237876ecddaa 100644
--- a/servo/components/script/dom/keyboardevent.rs
+++ b/servo/components/script/dom/keyboardevent.rs
@@ -61,7 +61,7 @@ impl KeyboardEvent {
     }
 
     pub fn new_uninitialized(window: &Window) -> DomRoot<KeyboardEvent> {
-        reflect_dom_object(box KeyboardEvent::new_inherited(),
+        reflect_dom_object(Box::new(KeyboardEvent::new_inherited()),
                            window,
                            KeyboardEventBinding::Wrap)
     }
diff --git a/servo/components/script/dom/location.rs b/servo/components/script/dom/location.rs
index 868b9df22660..af66934802a3 100644
--- a/servo/components/script/dom/location.rs
+++ b/servo/components/script/dom/location.rs
@@ -30,7 +30,7 @@ impl Location {
     }
 
     pub fn new(window: &Window) -> DomRoot<Location> {
-        reflect_dom_object(box Location::new_inherited(window),
+        reflect_dom_object(Box::new(Location::new_inherited(window)),
                            window,
                            LocationBinding::Wrap)
     }
diff --git a/servo/components/script/dom/macros.rs b/servo/components/script/dom/macros.rs
index 89d545d80f26..cf3ea6f6e12f 100644
--- a/servo/components/script/dom/macros.rs
+++ b/servo/components/script/dom/macros.rs
@@ -610,7 +610,7 @@ macro_rules! impl_performance_entry_struct(
                        start_time: f64,
                        duration: f64) -> DomRoot<$struct> {
                 let entry = $struct::new_inherited(name, start_time, duration);
-                reflect_dom_object(box entry, global, $binding::Wrap)
+                reflect_dom_object(Box::new(entry), global, $binding::Wrap)
             }
         }
     );
diff --git a/servo/components/script/dom/mediaerror.rs b/servo/components/script/dom/mediaerror.rs
index d8176e690447..09edba17888b 100644
--- a/servo/components/script/dom/mediaerror.rs
+++ b/servo/components/script/dom/mediaerror.rs
@@ -24,7 +24,7 @@ impl MediaError {
     }
 
     pub fn new(window: &Window, code: u16) -> DomRoot<MediaError> {
-        reflect_dom_object(box MediaError::new_inherited(code),
+        reflect_dom_object(Box::new(MediaError::new_inherited(code)),
                            window,
                            MediaErrorBinding::Wrap)
     }
diff --git a/servo/components/script/dom/medialist.rs b/servo/components/script/dom/medialist.rs
index 8b67de260719..df59886226d6 100644
--- a/servo/components/script/dom/medialist.rs
+++ b/servo/components/script/dom/medialist.rs
@@ -43,7 +43,7 @@ impl MediaList {
     pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
                media_queries: Arc<Locked<StyleMediaList>>)
         -> DomRoot<MediaList> {
-        reflect_dom_object(box MediaList::new_inherited(parent_stylesheet, media_queries),
+        reflect_dom_object(Box::new(MediaList::new_inherited(parent_stylesheet, media_queries)),
                            window,
                            MediaListBinding::Wrap)
     }
diff --git a/servo/components/script/dom/mediaquerylist.rs b/servo/components/script/dom/mediaquerylist.rs
index 97f6f5907798..87a28b710125 100644
--- a/servo/components/script/dom/mediaquerylist.rs
+++ b/servo/components/script/dom/mediaquerylist.rs
@@ -49,7 +49,7 @@ impl MediaQueryList {
     }
 
     pub fn new(document: &Document, media_query_list: MediaList) -> DomRoot<MediaQueryList> {
-        reflect_dom_object(box MediaQueryList::new_inherited(document, media_query_list),
+        reflect_dom_object(Box::new(MediaQueryList::new_inherited(document, media_query_list)),
                            document.window(),
                            MediaQueryListBinding::Wrap)
     }
diff --git a/servo/components/script/dom/mediaquerylistevent.rs b/servo/components/script/dom/mediaquerylistevent.rs
index 8eb1c8a3520b..c06da109d6db 100644
--- a/servo/components/script/dom/mediaquerylistevent.rs
+++ b/servo/components/script/dom/mediaquerylistevent.rs
@@ -30,11 +30,11 @@ impl MediaQueryListEvent {
     pub fn new_initialized(global: &GlobalScope,
                            media: DOMString,
                            matches: bool) -> DomRoot<MediaQueryListEvent> {
-        let ev = box MediaQueryListEvent {
+        let ev = Box::new(MediaQueryListEvent {
             event: Event::new_inherited(),
             media: media,
             matches: Cell::new(matches)
-        };
+        });
         reflect_dom_object(ev, global, MediaQueryListEventBinding::Wrap)
     }
 
diff --git a/servo/components/script/dom/messageevent.rs b/servo/components/script/dom/messageevent.rs
index cab9e245f8a1..2f515a1094dd 100644
--- a/servo/components/script/dom/messageevent.rs
+++ b/servo/components/script/dom/messageevent.rs
@@ -39,12 +39,12 @@ impl MessageEvent {
                            data: HandleValue,
                            origin: DOMString,
                            lastEventId: DOMString) -> DomRoot<MessageEvent> {
-        let ev = box MessageEvent {
+        let ev = Box::new(MessageEvent {
             event: Event::new_inherited(),
             data: Heap::default(),
             origin: origin,
             lastEventId: lastEventId,
-        };
+        });
         let ev = reflect_dom_object(ev, global, MessageEventBinding::Wrap);
         ev.data.set(data.get());
 
diff --git a/servo/components/script/dom/mimetypearray.rs b/servo/components/script/dom/mimetypearray.rs
index 7a195e3fe7f6..82528fc62ff3 100644
--- a/servo/components/script/dom/mimetypearray.rs
+++ b/servo/components/script/dom/mimetypearray.rs
@@ -24,7 +24,7 @@ impl MimeTypeArray {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<MimeTypeArray> {
-        reflect_dom_object(box MimeTypeArray::new_inherited(),
+        reflect_dom_object(Box::new(MimeTypeArray::new_inherited()),
                            global,
                            MimeTypeArrayBinding::Wrap)
     }
diff --git a/servo/components/script/dom/mouseevent.rs b/servo/components/script/dom/mouseevent.rs
index 2fa79f433868..7e6fbd52eb80 100644
--- a/servo/components/script/dom/mouseevent.rs
+++ b/servo/components/script/dom/mouseevent.rs
@@ -52,7 +52,7 @@ impl MouseEvent {
     }
 
     pub fn new_uninitialized(window: &Window) -> DomRoot<MouseEvent> {
-        reflect_dom_object(box MouseEvent::new_inherited(),
+        reflect_dom_object(Box::new(MouseEvent::new_inherited()),
                            window,
                            MouseEventBinding::Wrap)
     }
diff --git a/servo/components/script/dom/mutationobserver.rs b/servo/components/script/dom/mutationobserver.rs
index 72996a782899..5fbdad7f01fe 100644
--- a/servo/components/script/dom/mutationobserver.rs
+++ b/servo/components/script/dom/mutationobserver.rs
@@ -54,7 +54,7 @@ pub struct ObserverOptions {
 
 impl MutationObserver {
     fn new(global: &Window, callback: Rc<MutationCallback>) -> DomRoot<MutationObserver> {
-        let boxed_observer = box MutationObserver::new_inherited(callback);
+        let boxed_observer = Box::new(MutationObserver::new_inherited(callback));
         reflect_dom_object(boxed_observer, global, MutationObserverBinding::Wrap)
     }
 
diff --git a/servo/components/script/dom/mutationrecord.rs b/servo/components/script/dom/mutationrecord.rs
index a3b381821477..dff1a7c0b850 100644
--- a/servo/components/script/dom/mutationrecord.rs
+++ b/servo/components/script/dom/mutationrecord.rs
@@ -32,12 +32,14 @@ impl MutationRecord {
                              attribute_name: &LocalName,
                              attribute_namespace: Option<&Namespace>,
                              old_value: Option<DOMString>) -> DomRoot<MutationRecord> {
-        let record = box MutationRecord::new_inherited("attributes",
-                                                       target,
-                                                       Some(DOMString::from(&**attribute_name)),
-                                                       attribute_namespace.map(|n| DOMString::from(&**n)),
-                                                       old_value,
-                                                       None, None, None, None);
+        let record = Box::new(MutationRecord::new_inherited(
+            "attributes",
+            target,
+            Some(DOMString::from(&**attribute_name)),
+            attribute_namespace.map(|n| DOMString::from(&**n)),
+            old_value,
+            None, None, None, None
+        ));
         reflect_dom_object(record, &*window_from_node(target), MutationRecordBinding::Wrap)
     }
 
@@ -50,15 +52,19 @@ impl MutationRecord {
         let added_nodes = added_nodes.map(|list| NodeList::new_simple_list_slice(&window, list));
         let removed_nodes = removed_nodes.map(|list| NodeList::new_simple_list_slice(&window, list));
 
-        reflect_dom_object(box MutationRecord::new_inherited("childList",
-                                                             target,
-                                                             None, None, None,
-                                                             added_nodes.as_ref().map(|list| &**list),
-                                                             removed_nodes.as_ref().map(|list| &**list),
-                                                             next_sibling,
-                                                             prev_sibling),
-                           &*window,
-                           MutationRecordBinding::Wrap)
+        reflect_dom_object(
+            Box::new(MutationRecord::new_inherited(
+                "childList",
+                target,
+                None, None, None,
+                added_nodes.as_ref().map(|list| &**list),
+                removed_nodes.as_ref().map(|list| &**list),
+                next_sibling,
+                prev_sibling
+            )),
+            &*window,
+            MutationRecordBinding::Wrap
+        )
     }
 
     fn new_inherited(record_type: &str,
diff --git a/servo/components/script/dom/namednodemap.rs b/servo/components/script/dom/namednodemap.rs
index 023665371cfd..a7c9b8a9e597 100644
--- a/servo/components/script/dom/namednodemap.rs
+++ b/servo/components/script/dom/namednodemap.rs
@@ -32,7 +32,7 @@ impl NamedNodeMap {
     }
 
     pub fn new(window: &Window, elem: &Element) -> DomRoot<NamedNodeMap> {
-        reflect_dom_object(box NamedNodeMap::new_inherited(elem),
+        reflect_dom_object(Box::new(NamedNodeMap::new_inherited(elem)),
                            window, NamedNodeMapBinding::Wrap)
     }
 }
diff --git a/servo/components/script/dom/navigator.rs b/servo/components/script/dom/navigator.rs
index 5d3e41dc4212..ea50d3b2db60 100644
--- a/servo/components/script/dom/navigator.rs
+++ b/servo/components/script/dom/navigator.rs
@@ -48,7 +48,7 @@ impl Navigator {
     }
 
     pub fn new(window: &Window) -> DomRoot<Navigator> {
-        reflect_dom_object(box Navigator::new_inherited(),
+        reflect_dom_object(Box::new(Navigator::new_inherited()),
                            window,
                            NavigatorBinding::Wrap)
     }
diff --git a/servo/components/script/dom/node.rs b/servo/components/script/dom/node.rs
index a620d09433d5..beed58d76470 100644
--- a/servo/components/script/dom/node.rs
+++ b/servo/components/script/dom/node.rs
@@ -2727,7 +2727,7 @@ impl UniqueId {
         unsafe {
             let ptr = self.cell.get();
             if (*ptr).is_none() {
-                *ptr = Some(box Uuid::new_v4());
+                *ptr = Some(Box::new(Uuid::new_v4()));
             }
             &(&*ptr).as_ref().unwrap()
         }
diff --git a/servo/components/script/dom/nodeiterator.rs b/servo/components/script/dom/nodeiterator.rs
index 3ee09742e67c..688f46e7df7e 100644
--- a/servo/components/script/dom/nodeiterator.rs
+++ b/servo/components/script/dom/nodeiterator.rs
@@ -47,7 +47,7 @@ impl NodeIterator {
                            root_node: &Node,
                            what_to_show: u32,
                            filter: Filter) -> DomRoot<NodeIterator> {
-        reflect_dom_object(box NodeIterator::new_inherited(root_node, what_to_show, filter),
+        reflect_dom_object(Box::new(NodeIterator::new_inherited(root_node, what_to_show, filter)),
                            document.window(),
                            NodeIteratorBinding::Wrap)
     }
diff --git a/servo/components/script/dom/nodelist.rs b/servo/components/script/dom/nodelist.rs
index d6c0a394c935..86d8a2a951d5 100644
--- a/servo/components/script/dom/nodelist.rs
+++ b/servo/components/script/dom/nodelist.rs
@@ -37,7 +37,7 @@ impl NodeList {
 
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, list_type: NodeListType) -> DomRoot<NodeList> {
-        reflect_dom_object(box NodeList::new_inherited(list_type),
+        reflect_dom_object(Box::new(NodeList::new_inherited(list_type)),
                            window,
                            NodeListBinding::Wrap)
     }
diff --git a/servo/components/script/dom/pagetransitionevent.rs b/servo/components/script/dom/pagetransitionevent.rs
index 936c262eb52a..e9ef86a626dc 100644
--- a/servo/components/script/dom/pagetransitionevent.rs
+++ b/servo/components/script/dom/pagetransitionevent.rs
@@ -32,7 +32,7 @@ impl PageTransitionEvent {
     }
 
     pub fn new_uninitialized(window: &Window) -> DomRoot<PageTransitionEvent> {
-        reflect_dom_object(box PageTransitionEvent::new_inherited(),
+        reflect_dom_object(Box::new(PageTransitionEvent::new_inherited()),
                            window,
                            PageTransitionEventBinding::Wrap)
     }
diff --git a/servo/components/script/dom/paintrenderingcontext2d.rs b/servo/components/script/dom/paintrenderingcontext2d.rs
index b5c47b2c08fe..69492e2d6851 100644
--- a/servo/components/script/dom/paintrenderingcontext2d.rs
+++ b/servo/components/script/dom/paintrenderingcontext2d.rs
@@ -53,7 +53,7 @@ impl PaintRenderingContext2D {
     }
 
     pub fn new(global: &PaintWorkletGlobalScope) -> DomRoot<PaintRenderingContext2D> {
-        reflect_dom_object(box PaintRenderingContext2D::new_inherited(global),
+        reflect_dom_object(Box::new(PaintRenderingContext2D::new_inherited(global)),
                            global,
                            PaintRenderingContext2DBinding::Wrap)
     }
diff --git a/servo/components/script/dom/paintsize.rs b/servo/components/script/dom/paintsize.rs
index 72ebc9884683..13db8b2fe91a 100644
--- a/servo/components/script/dom/paintsize.rs
+++ b/servo/components/script/dom/paintsize.rs
@@ -30,7 +30,7 @@ impl PaintSize {
     }
 
     pub fn new(global: &PaintWorkletGlobalScope, size: TypedSize2D<f32, CSSPixel>) -> DomRoot<PaintSize> {
-        reflect_dom_object(box PaintSize::new_inherited(size), global, PaintSizeBinding::Wrap)
+        reflect_dom_object(Box::new(PaintSize::new_inherited(size)), global, PaintSizeBinding::Wrap)
     }
 }
 
diff --git a/servo/components/script/dom/paintworkletglobalscope.rs b/servo/components/script/dom/paintworkletglobalscope.rs
index 322b6e5a5d86..3f70779175bd 100644
--- a/servo/components/script/dom/paintworkletglobalscope.rs
+++ b/servo/components/script/dom/paintworkletglobalscope.rs
@@ -97,7 +97,7 @@ impl PaintWorkletGlobalScope {
                init: &WorkletGlobalScopeInit)
                -> DomRoot<PaintWorkletGlobalScope> {
         debug!("Creating paint worklet global scope for pipeline {}.", pipeline_id);
-        let global = box PaintWorkletGlobalScope {
+        let global = Box::new(PaintWorkletGlobalScope {
             worklet_global: WorkletGlobalScope::new_inherited(pipeline_id, base_url, executor, init),
             image_cache: init.image_cache.clone(),
             paint_definitions: Default::default(),
@@ -114,7 +114,7 @@ impl PaintWorkletGlobalScope {
                 image_key: None,
                 missing_image_urls: Vec::new(),
             }),
-        };
+        });
         unsafe { PaintWorkletGlobalScopeBinding::Wrap(runtime.cx(), global) }
     }
 
diff --git a/servo/components/script/dom/performance.rs b/servo/components/script/dom/performance.rs
index 0aabbb6fc35b..f65cd35288d5 100644
--- a/servo/components/script/dom/performance.rs
+++ b/servo/components/script/dom/performance.rs
@@ -140,11 +140,11 @@ impl Performance {
     pub fn new(global: &GlobalScope,
                navigation_start: u64,
                navigation_start_precise: f64) -> DomRoot<Performance> {
-        reflect_dom_object(box Performance::new_inherited(global,
-                                                          navigation_start,
-                                                          navigation_start_precise),
-                           global,
-                           PerformanceBinding::Wrap)
+        reflect_dom_object(
+            Box::new(Performance::new_inherited(global, navigation_start, navigation_start_precise)),
+            global,
+            PerformanceBinding::Wrap
+        )
     }
 
     /// Add a PerformanceObserver to the list of observers with a set of
diff --git a/servo/components/script/dom/performanceentry.rs b/servo/components/script/dom/performanceentry.rs
index 01b8eb6ee956..964a808143bd 100644
--- a/servo/components/script/dom/performanceentry.rs
+++ b/servo/components/script/dom/performanceentry.rs
@@ -41,7 +41,7 @@ impl PerformanceEntry {
                start_time: f64,
                duration: f64) -> DomRoot<PerformanceEntry> {
         let entry = PerformanceEntry::new_inherited(name, entry_type, start_time, duration);
-        reflect_dom_object(box entry, global, PerformanceEntryBinding::Wrap)
+        reflect_dom_object(Box::new(entry), global, PerformanceEntryBinding::Wrap)
     }
 
     pub fn entry_type(&self) -> &DOMString {
diff --git a/servo/components/script/dom/performanceobserver.rs b/servo/components/script/dom/performanceobserver.rs
index 4393eff6d0f6..06c243e7818a 100644
--- a/servo/components/script/dom/performanceobserver.rs
+++ b/servo/components/script/dom/performanceobserver.rs
@@ -54,7 +54,7 @@ impl PerformanceObserver {
                entries: DOMPerformanceEntryList)
         -> DomRoot<PerformanceObserver> {
         let observer = PerformanceObserver::new_inherited(callback, DomRefCell::new(entries));
-        reflect_dom_object(box observer, global, PerformanceObserverBinding::Wrap)
+        reflect_dom_object(Box::new(observer), global, PerformanceObserverBinding::Wrap)
     }
 
     pub fn Constructor(global: &GlobalScope, callback: Rc<PerformanceObserverCallback>)
diff --git a/servo/components/script/dom/performanceobserverentrylist.rs b/servo/components/script/dom/performanceobserverentrylist.rs
index 70f329952d85..4721a5bf4406 100644
--- a/servo/components/script/dom/performanceobserverentrylist.rs
+++ b/servo/components/script/dom/performanceobserverentrylist.rs
@@ -31,7 +31,7 @@ impl PerformanceObserverEntryList {
     pub fn new(global: &GlobalScope, entries: PerformanceEntryList)
         -> DomRoot<PerformanceObserverEntryList> {
         let observer_entry_list = PerformanceObserverEntryList::new_inherited(entries);
-        reflect_dom_object(box observer_entry_list, global, PerformanceObserverEntryListBinding::Wrap)
+        reflect_dom_object(Box::new(observer_entry_list), global, PerformanceObserverEntryListBinding::Wrap)
     }
 }
 
diff --git a/servo/components/script/dom/performancepainttiming.rs b/servo/components/script/dom/performancepainttiming.rs
index b798d93a1408..4c25e785208c 100644
--- a/servo/components/script/dom/performancepainttiming.rs
+++ b/servo/components/script/dom/performancepainttiming.rs
@@ -36,6 +36,6 @@ impl PerformancePaintTiming {
                metric_type: PaintMetricType,
                start_time: f64) -> DomRoot<PerformancePaintTiming> {
         let entry = PerformancePaintTiming::new_inherited(metric_type, start_time);
-        reflect_dom_object(box entry, global, PerformancePaintTimingBinding::Wrap)
+        reflect_dom_object(Box::new(entry), global, PerformancePaintTimingBinding::Wrap)
     }
 }
diff --git a/servo/components/script/dom/performancetiming.rs b/servo/components/script/dom/performancetiming.rs
index d0833d76f64e..1192418a4b9a 100644
--- a/servo/components/script/dom/performancetiming.rs
+++ b/servo/components/script/dom/performancetiming.rs
@@ -40,7 +40,7 @@ impl PerformanceTiming {
         let timing = PerformanceTiming::new_inherited(navigation_start,
                                                       navigation_start_precise,
                                                       &window.Document());
-        reflect_dom_object(box timing,
+        reflect_dom_object(Box::new(timing),
                            window,
                            PerformanceTimingBinding::Wrap)
     }
diff --git a/servo/components/script/dom/permissions.rs b/servo/components/script/dom/permissions.rs
index 74fc675008ed..04f927322b12 100644
--- a/servo/components/script/dom/permissions.rs
+++ b/servo/components/script/dom/permissions.rs
@@ -64,7 +64,7 @@ impl Permissions {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<Permissions> {
-        reflect_dom_object(box Permissions::new_inherited(),
+        reflect_dom_object(Box::new(Permissions::new_inherited()),
                            global,
                            PermissionsBinding::Wrap)
     }
diff --git a/servo/components/script/dom/permissionstatus.rs b/servo/components/script/dom/permissionstatus.rs
index 13efaf65a0a6..eea9357d0423 100644
--- a/servo/components/script/dom/permissionstatus.rs
+++ b/servo/components/script/dom/permissionstatus.rs
@@ -31,7 +31,7 @@ impl PermissionStatus {
     }
 
     pub fn new(global: &GlobalScope, query: &PermissionDescriptor) -> DomRoot<PermissionStatus> {
-        reflect_dom_object(box PermissionStatus::new_inherited(query.name),
+        reflect_dom_object(Box::new(PermissionStatus::new_inherited(query.name)),
                            global,
                            PermissionStatusBinding::Wrap)
     }
diff --git a/servo/components/script/dom/pluginarray.rs b/servo/components/script/dom/pluginarray.rs
index c77b763eb85e..e2d0c12da276 100644
--- a/servo/components/script/dom/pluginarray.rs
+++ b/servo/components/script/dom/pluginarray.rs
@@ -24,7 +24,7 @@ impl PluginArray {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<PluginArray> {
-        reflect_dom_object(box PluginArray::new_inherited(),
+        reflect_dom_object(Box::new(PluginArray::new_inherited()),
                            global,
                            PluginArrayBinding::Wrap)
     }
diff --git a/servo/components/script/dom/popstateevent.rs b/servo/components/script/dom/popstateevent.rs
index 0a962dfe5be5..218ed5d3af6d 100644
--- a/servo/components/script/dom/popstateevent.rs
+++ b/servo/components/script/dom/popstateevent.rs
@@ -35,7 +35,7 @@ impl PopStateEvent {
     }
 
     pub fn new_uninitialized(window: &Window) -> DomRoot<PopStateEvent> {
-        reflect_dom_object(box PopStateEvent::new_inherited(),
+        reflect_dom_object(Box::new(PopStateEvent::new_inherited()),
                            window,
                            PopStateEventBinding::Wrap)
     }
diff --git a/servo/components/script/dom/processinginstruction.rs b/servo/components/script/dom/processinginstruction.rs
index 1cdb5eb1c4ca..d4eee64d2aa1 100644
--- a/servo/components/script/dom/processinginstruction.rs
+++ b/servo/components/script/dom/processinginstruction.rs
@@ -27,7 +27,7 @@ impl ProcessingInstruction {
     }
 
     pub fn new(target: DOMString, data: DOMString, document: &Document) -> DomRoot<ProcessingInstruction> {
-        Node::reflect_node(box ProcessingInstruction::new_inherited(target, data, document),
+        Node::reflect_node(Box::new(ProcessingInstruction::new_inherited(target, data, document)),
                            document, ProcessingInstructionBinding::Wrap)
     }
 }
diff --git a/servo/components/script/dom/progressevent.rs b/servo/components/script/dom/progressevent.rs
index 1ad4acacc47b..84f8004abc79 100644
--- a/servo/components/script/dom/progressevent.rs
+++ b/servo/components/script/dom/progressevent.rs
@@ -33,14 +33,14 @@ impl ProgressEvent {
         }
     }
     pub fn new_uninitialized(global: &GlobalScope) -> DomRoot<ProgressEvent> {
-        reflect_dom_object(box ProgressEvent::new_inherited(false, 0, 0),
+        reflect_dom_object(Box::new(ProgressEvent::new_inherited(false, 0, 0)),
                            global,
                            ProgressEventBinding::Wrap)
     }
     pub fn new(global: &GlobalScope, type_: Atom,
                can_bubble: EventBubbles, cancelable: EventCancelable,
                length_computable: bool, loaded: u64, total: u64) -> DomRoot<ProgressEvent> {
-        let ev = reflect_dom_object(box ProgressEvent::new_inherited(length_computable, loaded, total),
+        let ev = reflect_dom_object(Box::new(ProgressEvent::new_inherited(length_computable, loaded, total)),
                                     global,
                                     ProgressEventBinding::Wrap);
         {
diff --git a/servo/components/script/dom/promisenativehandler.rs b/servo/components/script/dom/promisenativehandler.rs
index 56c65c9a8011..4ed9b4b30b45 100644
--- a/servo/components/script/dom/promisenativehandler.rs
+++ b/servo/components/script/dom/promisenativehandler.rs
@@ -27,11 +27,11 @@ impl PromiseNativeHandler {
                resolve: Option<Box<Callback>>,
                reject: Option<Box<Callback>>)
                -> DomRoot<PromiseNativeHandler> {
-        reflect_dom_object(box PromiseNativeHandler {
+        reflect_dom_object(Box::new(PromiseNativeHandler {
             reflector: Reflector::new(),
             resolve: resolve,
             reject: reject,
-        }, global, PromiseNativeHandlerBinding::Wrap)
+        }), global, PromiseNativeHandlerBinding::Wrap)
     }
 
     fn callback(callback: &Option<Box<Callback>>, cx: *mut JSContext, v: HandleValue) {
diff --git a/servo/components/script/dom/radionodelist.rs b/servo/components/script/dom/radionodelist.rs
index d9c3a010c34b..8c8cd88b7428 100644
--- a/servo/components/script/dom/radionodelist.rs
+++ b/servo/components/script/dom/radionodelist.rs
@@ -31,7 +31,7 @@ impl RadioNodeList {
 
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, list_type: NodeListType) -> DomRoot<RadioNodeList> {
-        reflect_dom_object(box RadioNodeList::new_inherited(list_type),
+        reflect_dom_object(Box::new(RadioNodeList::new_inherited(list_type)),
                            window,
                            RadioNodeListBinding::Wrap)
     }
diff --git a/servo/components/script/dom/range.rs b/servo/components/script/dom/range.rs
index b6a05b31881c..00e2d23ce761 100644
--- a/servo/components/script/dom/range.rs
+++ b/servo/components/script/dom/range.rs
@@ -58,10 +58,13 @@ impl Range {
                start_container: &Node, start_offset: u32,
                end_container: &Node, end_offset: u32)
                -> DomRoot<Range> {
-        let range = reflect_dom_object(box Range::new_inherited(start_container, start_offset,
-                                                                end_container, end_offset),
-                                       document.window(),
-                                       RangeBinding::Wrap);
+        let range = reflect_dom_object(
+            Box::new(Range::new_inherited(
+                start_container, start_offset, end_container, end_offset
+            )),
+            document.window(),
+            RangeBinding::Wrap
+        );
         start_container.ranges().push(WeakRef::new(&range));
         if start_container != end_container {
             end_container.ranges().push(WeakRef::new(&range));
diff --git a/servo/components/script/dom/request.rs b/servo/components/script/dom/request.rs
index 204a7084f0a6..a4bfbf96f830 100644
--- a/servo/components/script/dom/request.rs
+++ b/servo/components/script/dom/request.rs
@@ -68,8 +68,7 @@ impl Request {
 
     pub fn new(global: &GlobalScope,
                url: ServoUrl) -> DomRoot<Request> {
-        reflect_dom_object(box Request::new_inherited(global,
-                                                      url),
+        reflect_dom_object(Box::new(Request::new_inherited(global, url)),
                            global, RequestBinding::Wrap)
     }
 
diff --git a/servo/components/script/dom/response.rs b/servo/components/script/dom/response.rs
index a874aac77e68..ee4276e711a2 100644
--- a/servo/components/script/dom/response.rs
+++ b/servo/components/script/dom/response.rs
@@ -3,7 +3,6 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use body::{BodyOperations, BodyType, consume_body, consume_body_with_promise};
-use core::cell::Cell;
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::HeadersBinding::{HeadersInit, HeadersMethods};
 use dom::bindings::codegen::Bindings::ResponseBinding;
@@ -24,7 +23,7 @@ use hyper::status::StatusCode;
 use hyper_serde::Serde;
 use net_traits::response::{ResponseBody as NetTraitsResponseBody};
 use servo_url::ServoUrl;
-use std::cell::Ref;
+use std::cell::{Cell, Ref};
 use std::mem;
 use std::rc::Rc;
 use std::str::FromStr;
@@ -68,7 +67,7 @@ impl Response {
 
     // https://fetch.spec.whatwg.org/#dom-response
     pub fn new(global: &GlobalScope) -> DomRoot<Response> {
-        reflect_dom_object(box Response::new_inherited(), global, ResponseBinding::Wrap)
+        reflect_dom_object(Box::new(Response::new_inherited()), global, ResponseBinding::Wrap)
     }
 
     pub fn Constructor(global: &GlobalScope, body: Option<BodyInit>, init: &ResponseBinding::ResponseInit)
diff --git a/servo/components/script/dom/screen.rs b/servo/components/script/dom/screen.rs
index 88a9025f76f2..cfb827db6f0c 100644
--- a/servo/components/script/dom/screen.rs
+++ b/servo/components/script/dom/screen.rs
@@ -22,7 +22,7 @@ impl Screen {
     }
 
     pub fn new(window: &Window) -> DomRoot<Screen> {
-        reflect_dom_object(box Screen::new_inherited(),
+        reflect_dom_object(Box::new(Screen::new_inherited()),
                            window,
                            ScreenBinding::Wrap)
     }
diff --git a/servo/components/script/dom/serviceworker.rs b/servo/components/script/dom/serviceworker.rs
index 95c37d27c8e9..5943eb22a427 100644
--- a/servo/components/script/dom/serviceworker.rs
+++ b/servo/components/script/dom/serviceworker.rs
@@ -49,9 +49,13 @@ impl ServiceWorker {
                                  script_url: ServoUrl,
                                  scope_url: ServoUrl,
                                  skip_waiting: bool) -> DomRoot<ServiceWorker> {
-        reflect_dom_object(box ServiceWorker::new_inherited(script_url.as_str(),
-                                                            skip_waiting,
-                                                            scope_url), global, Wrap)
+        reflect_dom_object(
+            Box::new(ServiceWorker::new_inherited(
+                script_url.as_str(), skip_waiting, scope_url
+            )),
+            global,
+            Wrap
+        )
     }
 
     pub fn dispatch_simple_error(address: TrustedServiceWorkerAddress) {
diff --git a/servo/components/script/dom/serviceworkercontainer.rs b/servo/components/script/dom/serviceworkercontainer.rs
index 9c853be24032..83f7db6c4c94 100644
--- a/servo/components/script/dom/serviceworkercontainer.rs
+++ b/servo/components/script/dom/serviceworkercontainer.rs
@@ -40,7 +40,7 @@ impl ServiceWorkerContainer {
     pub fn new(global: &GlobalScope) -> DomRoot<ServiceWorkerContainer> {
         let client = Client::new(&global.as_window());
         let container = ServiceWorkerContainer::new_inherited(&*client);
-        reflect_dom_object(box container, global, Wrap)
+        reflect_dom_object(Box::new(container), global, Wrap)
     }
 }
 
diff --git a/servo/components/script/dom/serviceworkerglobalscope.rs b/servo/components/script/dom/serviceworkerglobalscope.rs
index 3183598e2298..bd9de0db9f5d 100644
--- a/servo/components/script/dom/serviceworkerglobalscope.rs
+++ b/servo/components/script/dom/serviceworkerglobalscope.rs
@@ -62,9 +62,9 @@ impl ScriptChan for ServiceWorkerChan {
     }
 
     fn clone(&self) -> Box<ScriptChan + Send> {
-        box ServiceWorkerChan {
+        Box::new(ServiceWorkerChan {
             sender: self.sender.clone(),
-        }
+        })
     }
 }
 
@@ -122,16 +122,18 @@ impl ServiceWorkerGlobalScope {
                scope_url: ServoUrl)
                -> DomRoot<ServiceWorkerGlobalScope> {
         let cx = runtime.cx();
-        let scope = box ServiceWorkerGlobalScope::new_inherited(init,
-                                                                  worker_url,
-                                                                  from_devtools_receiver,
-                                                                  runtime,
-                                                                  own_sender,
-                                                                  receiver,
-                                                                  timer_event_chan,
-                                                                  timer_event_port,
-                                                                  swmanager_sender,
-                                                                  scope_url);
+        let scope = Box::new(ServiceWorkerGlobalScope::new_inherited(
+            init,
+            worker_url,
+            from_devtools_receiver,
+            runtime,
+            own_sender,
+            receiver,
+            timer_event_chan,
+            timer_event_port,
+            swmanager_sender,
+            scope_url
+        ));
         unsafe {
             ServiceWorkerGlobalScopeBinding::Wrap(cx, scope)
         }
@@ -307,9 +309,9 @@ impl ServiceWorkerGlobalScope {
     }
 
     pub fn script_chan(&self) -> Box<ScriptChan + Send> {
-        box ServiceWorkerChan {
+        Box::new(ServiceWorkerChan {
             sender: self.own_sender.clone()
-        }
+        })
     }
 
     fn dispatch_activate(&self) {
diff --git a/servo/components/script/dom/serviceworkerregistration.rs b/servo/components/script/dom/serviceworkerregistration.rs
index aab043909437..a16c1418971f 100644
--- a/servo/components/script/dom/serviceworkerregistration.rs
+++ b/servo/components/script/dom/serviceworkerregistration.rs
@@ -44,7 +44,7 @@ impl ServiceWorkerRegistration {
                scope: ServoUrl) -> DomRoot<ServiceWorkerRegistration> {
         let active_worker = ServiceWorker::install_serviceworker(global, script_url.clone(), scope.clone(), true);
         active_worker.set_transition_state(ServiceWorkerState::Installed);
-        reflect_dom_object(box ServiceWorkerRegistration::new_inherited(&*active_worker, scope), global, Wrap)
+        reflect_dom_object(Box::new(ServiceWorkerRegistration::new_inherited(&*active_worker, scope)), global, Wrap)
     }
 
     pub fn get_installed(&self) -> &ServiceWorker {
diff --git a/servo/components/script/dom/servoparser/mod.rs b/servo/components/script/dom/servoparser/mod.rs
index b458bc047be3..f531250d3829 100644
--- a/servo/components/script/dom/servoparser/mod.rs
+++ b/servo/components/script/dom/servoparser/mod.rs
@@ -338,7 +338,7 @@ impl ServoParser {
            last_chunk_state: LastChunkState,
            kind: ParserKind)
            -> DomRoot<Self> {
-        reflect_dom_object(box ServoParser::new_inherited(document, tokenizer, last_chunk_state, kind),
+        reflect_dom_object(Box::new(ServoParser::new_inherited(document, tokenizer, last_chunk_state, kind)),
                            document.window(),
                            ServoParserBinding::Wrap)
     }
diff --git a/servo/components/script/dom/storage.rs b/servo/components/script/dom/storage.rs
index 56d5e8328709..6a48c236302a 100644
--- a/servo/components/script/dom/storage.rs
+++ b/servo/components/script/dom/storage.rs
@@ -36,7 +36,7 @@ impl Storage {
     }
 
     pub fn new(global: &Window, storage_type: StorageType) -> DomRoot<Storage> {
-        reflect_dom_object(box Storage::new_inherited(storage_type), global, StorageBinding::Wrap)
+        reflect_dom_object(Box::new(Storage::new_inherited(storage_type)), global, StorageBinding::Wrap)
     }
 
     fn get_url(&self) -> ServoUrl {
diff --git a/servo/components/script/dom/storageevent.rs b/servo/components/script/dom/storageevent.rs
index 382cdc612b4a..0070a2c1e68c 100644
--- a/servo/components/script/dom/storageevent.rs
+++ b/servo/components/script/dom/storageevent.rs
@@ -45,7 +45,7 @@ impl StorageEvent {
 
     pub fn new_uninitialized(window: &Window,
                              url: DOMString) -> DomRoot<StorageEvent> {
-        reflect_dom_object(box StorageEvent::new_inherited(None, None, None, url, None),
+        reflect_dom_object(Box::new(StorageEvent::new_inherited(None, None, None, url, None)),
                            window,
                            StorageEventBinding::Wrap)
     }
@@ -59,10 +59,11 @@ impl StorageEvent {
                newValue: Option<DOMString>,
                url: DOMString,
                storageArea: Option<&Storage>) -> DomRoot<StorageEvent> {
-        let ev = reflect_dom_object(box StorageEvent::new_inherited(key, oldValue, newValue,
-                                                                    url, storageArea),
-                                    global,
-                                    StorageEventBinding::Wrap);
+        let ev = reflect_dom_object(
+            Box::new(StorageEvent::new_inherited(key, oldValue, newValue, url, storageArea)),
+            global,
+            StorageEventBinding::Wrap
+        );
         {
             let event = ev.upcast::<Event>();
             event.init_event(type_, bool::from(bubbles), bool::from(cancelable));
diff --git a/servo/components/script/dom/stylepropertymapreadonly.rs b/servo/components/script/dom/stylepropertymapreadonly.rs
index 4002a68c0d49..e387e5c70cb7 100644
--- a/servo/components/script/dom/stylepropertymapreadonly.rs
+++ b/servo/components/script/dom/stylepropertymapreadonly.rs
@@ -48,7 +48,7 @@ impl StylePropertyMapReadOnly {
             values.push(Dom::from_ref(&*value));
         }
         let iter = keys.drain(..).zip(values.iter().cloned());
-        reflect_dom_object(box StylePropertyMapReadOnly::new_inherited(iter), global, Wrap)
+        reflect_dom_object(Box::new(StylePropertyMapReadOnly::new_inherited(iter)), global, Wrap)
     }
 }
 
diff --git a/servo/components/script/dom/stylesheet.rs b/servo/components/script/dom/stylesheet.rs
index 6315fe19ccd0..d53971cf927f 100644
--- a/servo/components/script/dom/stylesheet.rs
+++ b/servo/components/script/dom/stylesheet.rs
@@ -37,7 +37,7 @@ impl StyleSheet {
     pub fn new(window: &Window, type_: DOMString,
                href: Option<DOMString>,
                title: Option<DOMString>) -> DomRoot<StyleSheet> {
-        reflect_dom_object(box StyleSheet::new_inherited(type_, href, title),
+        reflect_dom_object(Box::new(StyleSheet::new_inherited(type_, href, title)),
                            window,
                            StyleSheetBinding::Wrap)
     }
diff --git a/servo/components/script/dom/stylesheetlist.rs b/servo/components/script/dom/stylesheetlist.rs
index 15c524e83a3a..6ae8f0bd7696 100644
--- a/servo/components/script/dom/stylesheetlist.rs
+++ b/servo/components/script/dom/stylesheetlist.rs
@@ -28,7 +28,7 @@ impl StyleSheetList {
 
     #[allow(unrooted_must_root)]
     pub fn new(window: &Window, document: Dom<Document>) -> DomRoot<StyleSheetList> {
-        reflect_dom_object(box StyleSheetList::new_inherited(document),
+        reflect_dom_object(Box::new(StyleSheetList::new_inherited(document)),
                            window, StyleSheetListBinding::Wrap)
     }
 }
diff --git a/servo/components/script/dom/svgsvgelement.rs b/servo/components/script/dom/svgsvgelement.rs
index b7ee599b1025..b057a3c4b31f 100644
--- a/servo/components/script/dom/svgsvgelement.rs
+++ b/servo/components/script/dom/svgsvgelement.rs
@@ -39,7 +39,7 @@ impl SVGSVGElement {
     pub fn new(local_name: LocalName,
                prefix: Option<Prefix>,
                document: &Document) -> DomRoot<SVGSVGElement> {
-        Node::reflect_node(box SVGSVGElement::new_inherited(local_name, prefix, document),
+        Node::reflect_node(Box::new(SVGSVGElement::new_inherited(local_name, prefix, document)),
                            document,
                            SVGSVGElementBinding::Wrap)
     }
diff --git a/servo/components/script/dom/testbinding.rs b/servo/components/script/dom/testbinding.rs
index 3f76dab22471..62738fcf3799 100644
--- a/servo/components/script/dom/testbinding.rs
+++ b/servo/components/script/dom/testbinding.rs
@@ -4,7 +4,6 @@
 
 // check-tidy: no specs after this line
 
-use core::nonzero::NonZero;
 use dom::bindings::callback::ExceptionHandling;
 use dom::bindings::codegen::Bindings::EventListenerBinding::EventListener;
 use dom::bindings::codegen::Bindings::FunctionBinding::Function;
@@ -22,6 +21,7 @@ use dom::bindings::codegen::UnionTypes::{StringOrLongSequence, StringOrStringSeq
 use dom::bindings::codegen::UnionTypes::{StringOrUnsignedLong, StringOrBoolean, UnsignedLongOrBoolean};
 use dom::bindings::error::{Error, Fallible};
 use dom::bindings::mozmap::MozMap;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::refcounted::TrustedPromise;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
@@ -60,7 +60,7 @@ impl TestBinding {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<TestBinding> {
-        reflect_dom_object(box TestBinding::new_inherited(),
+        reflect_dom_object(Box::new(TestBinding::new_inherited()),
                            global, TestBindingBinding::Wrap)
     }
 
@@ -151,20 +151,20 @@ impl TestBindingMethods for TestBinding {
     }
     fn SetUnion9Attribute(&self, _: ByteStringOrLong) {}
     #[allow(unsafe_code)]
-    unsafe fn ArrayAttribute(&self, cx: *mut JSContext) -> NonZero<*mut JSObject> {
+    unsafe fn ArrayAttribute(&self, cx: *mut JSContext) -> NonNullJSObjectPtr {
         rooted!(in(cx) let array = JS_NewUint8ClampedArray(cx, 16));
         assert!(!array.is_null());
-        NonZero::new_unchecked(array.get())
+        NonNullJSObjectPtr::new_unchecked(array.get())
     }
     #[allow(unsafe_code)]
     unsafe fn AnyAttribute(&self, _: *mut JSContext) -> JSVal { NullValue() }
     #[allow(unsafe_code)]
     unsafe fn SetAnyAttribute(&self, _: *mut JSContext, _: HandleValue) {}
     #[allow(unsafe_code)]
-    unsafe fn ObjectAttribute(&self, cx: *mut JSContext) -> NonZero<*mut JSObject> {
+    unsafe fn ObjectAttribute(&self, cx: *mut JSContext) -> NonNullJSObjectPtr {
         rooted!(in(cx) let obj = JS_NewPlainObject(cx));
         assert!(!obj.is_null());
-        NonZero::new_unchecked(obj.get())
+        NonNullJSObjectPtr::new_unchecked(obj.get())
     }
     #[allow(unsafe_code)]
     unsafe fn SetObjectAttribute(&self, _: *mut JSContext, _: *mut JSObject) {}
@@ -220,7 +220,7 @@ impl TestBindingMethods for TestBinding {
         self.url.set(url);
     }
     #[allow(unsafe_code)]
-    unsafe fn GetObjectAttributeNullable(&self, _: *mut JSContext) -> Option<NonZero<*mut JSObject>> { None }
+    unsafe fn GetObjectAttributeNullable(&self, _: *mut JSContext) -> Option<NonNullJSObjectPtr> { None }
     #[allow(unsafe_code)]
     unsafe fn SetObjectAttributeNullable(&self, _: *mut JSContext, _: *mut JSObject) {}
     fn GetUnionAttributeNullable(&self) -> Option<HTMLElementOrLong> {
@@ -272,7 +272,7 @@ impl TestBindingMethods for TestBinding {
     #[allow(unsafe_code)]
     unsafe fn ReceiveAny(&self, _: *mut JSContext) -> JSVal { NullValue() }
     #[allow(unsafe_code)]
-    unsafe fn ReceiveObject(&self, cx: *mut JSContext) -> NonZero<*mut JSObject> {
+    unsafe fn ReceiveObject(&self, cx: *mut JSContext) -> NonNullJSObjectPtr {
         self.ObjectAttribute(cx)
     }
     fn ReceiveUnion(&self) -> HTMLElementOrLong { HTMLElementOrLong::Long(0) }
@@ -316,7 +316,7 @@ impl TestBindingMethods for TestBinding {
         Some(Blob::new(&self.global(), BlobImpl::new_from_bytes(vec![]), "".to_owned()))
     }
     #[allow(unsafe_code)]
-    unsafe fn ReceiveNullableObject(&self, cx: *mut JSContext) -> Option<NonZero<*mut JSObject>> {
+    unsafe fn ReceiveNullableObject(&self, cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
         self.GetObjectAttributeNullable(cx)
     }
     fn ReceiveNullableUnion(&self) -> Option<HTMLElementOrLong> {
@@ -730,7 +730,7 @@ impl TestBindingMethods for TestBinding {
         }
         impl SimpleHandler {
             fn new(callback: Rc<SimpleCallback>) -> Box<Callback> {
-                box SimpleHandler { handler: callback }
+                Box::new(SimpleHandler { handler: callback })
             }
         }
         impl Callback for SimpleHandler {
diff --git a/servo/components/script/dom/testbindingiterable.rs b/servo/components/script/dom/testbindingiterable.rs
index 9f9354b88157..06a9dda6b379 100644
--- a/servo/components/script/dom/testbindingiterable.rs
+++ b/servo/components/script/dom/testbindingiterable.rs
@@ -21,10 +21,10 @@ pub struct TestBindingIterable {
 
 impl TestBindingIterable {
     fn new(global: &GlobalScope) -> DomRoot<TestBindingIterable> {
-        reflect_dom_object(box TestBindingIterable {
+        reflect_dom_object(Box::new(TestBindingIterable {
             reflector: Reflector::new(),
             vals: DomRefCell::new(vec![]),
-        }, global, TestBindingIterableBinding::Wrap)
+        }), global, TestBindingIterableBinding::Wrap)
     }
 
     pub fn Constructor(global: &GlobalScope) -> Fallible<DomRoot<TestBindingIterable>> {
diff --git a/servo/components/script/dom/testbindingpairiterable.rs b/servo/components/script/dom/testbindingpairiterable.rs
index 5fae49893aa6..2fa90f48fc6f 100644
--- a/servo/components/script/dom/testbindingpairiterable.rs
+++ b/servo/components/script/dom/testbindingpairiterable.rs
@@ -37,10 +37,10 @@ impl Iterable for TestBindingPairIterable {
 
 impl TestBindingPairIterable {
     fn new(global: &GlobalScope) -> DomRoot<TestBindingPairIterable> {
-        reflect_dom_object(box TestBindingPairIterable {
+        reflect_dom_object(Box::new(TestBindingPairIterable {
             reflector: Reflector::new(),
             map: DomRefCell::new(vec![]),
-        }, global, TestBindingPairIterableBinding::TestBindingPairIterableWrap)
+        }), global, TestBindingPairIterableBinding::TestBindingPairIterableWrap)
     }
 
     pub fn Constructor(global: &GlobalScope) -> Fallible<DomRoot<TestBindingPairIterable>> {
diff --git a/servo/components/script/dom/testrunner.rs b/servo/components/script/dom/testrunner.rs
index 972bc7297234..84a533786b81 100644
--- a/servo/components/script/dom/testrunner.rs
+++ b/servo/components/script/dom/testrunner.rs
@@ -27,7 +27,7 @@ impl TestRunner {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<TestRunner> {
-        reflect_dom_object(box TestRunner::new_inherited(),
+        reflect_dom_object(Box::new(TestRunner::new_inherited()),
                            global,
                            TestRunnerBinding::Wrap)
     }
diff --git a/servo/components/script/dom/testworklet.rs b/servo/components/script/dom/testworklet.rs
index 04ed5ffc3c43..61a08a2b18f0 100644
--- a/servo/components/script/dom/testworklet.rs
+++ b/servo/components/script/dom/testworklet.rs
@@ -38,7 +38,7 @@ impl TestWorklet {
 
     fn new(window: &Window) -> DomRoot<TestWorklet> {
         let worklet = Worklet::new(window, WorkletGlobalScopeType::Test);
-        reflect_dom_object(box TestWorklet::new_inherited(&*worklet), window, Wrap)
+        reflect_dom_object(Box::new(TestWorklet::new_inherited(&*worklet)), window, Wrap)
     }
 
     pub fn Constructor(window: &Window) -> Fallible<DomRoot<TestWorklet>> {
diff --git a/servo/components/script/dom/testworkletglobalscope.rs b/servo/components/script/dom/testworkletglobalscope.rs
index 54b2c299df78..22be6a4765f6 100644
--- a/servo/components/script/dom/testworkletglobalscope.rs
+++ b/servo/components/script/dom/testworkletglobalscope.rs
@@ -37,10 +37,10 @@ impl TestWorkletGlobalScope {
                -> DomRoot<TestWorkletGlobalScope>
     {
         debug!("Creating test worklet global scope for pipeline {}.", pipeline_id);
-        let global = box TestWorkletGlobalScope {
+        let global = Box::new(TestWorkletGlobalScope {
             worklet_global: WorkletGlobalScope::new_inherited(pipeline_id, base_url, executor, init),
             lookup_table: Default::default(),
-        };
+        });
         unsafe { TestWorkletGlobalScopeBinding::Wrap(runtime.cx(), global) }
     }
 
diff --git a/servo/components/script/dom/text.rs b/servo/components/script/dom/text.rs
index 2e37edc1a8dd..3e33c6642bbc 100644
--- a/servo/components/script/dom/text.rs
+++ b/servo/components/script/dom/text.rs
@@ -31,7 +31,7 @@ impl Text {
     }
 
     pub fn new(text: DOMString, document: &Document) -> DomRoot<Text> {
-        Node::reflect_node(box Text::new_inherited(text, document),
+        Node::reflect_node(Box::new(Text::new_inherited(text, document)),
                            document, TextBinding::Wrap)
     }
 
diff --git a/servo/components/script/dom/textdecoder.rs b/servo/components/script/dom/textdecoder.rs
index 56e32ed5245f..37e694c052b2 100644
--- a/servo/components/script/dom/textdecoder.rs
+++ b/servo/components/script/dom/textdecoder.rs
@@ -37,7 +37,7 @@ impl TextDecoder {
     }
 
     pub fn new(global: &GlobalScope, encoding: EncodingRef, fatal: bool) -> DomRoot<TextDecoder> {
-        reflect_dom_object(box TextDecoder::new_inherited(encoding, fatal),
+        reflect_dom_object(Box::new(TextDecoder::new_inherited(encoding, fatal)),
                            global,
                            TextDecoderBinding::Wrap)
     }
diff --git a/servo/components/script/dom/textencoder.rs b/servo/components/script/dom/textencoder.rs
index 765024522388..7ca2a4295258 100644
--- a/servo/components/script/dom/textencoder.rs
+++ b/servo/components/script/dom/textencoder.rs
@@ -2,16 +2,16 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use core::nonzero::NonZero;
 use dom::bindings::codegen::Bindings::TextEncoderBinding;
 use dom::bindings::codegen::Bindings::TextEncoderBinding::TextEncoderMethods;
 use dom::bindings::error::Fallible;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
 use dom::bindings::str::{DOMString, USVString};
 use dom::globalscope::GlobalScope;
 use dom_struct::dom_struct;
-use js::jsapi::{JSContext, JSObject};
+use js::jsapi::JSContext;
 use js::typedarray::{Uint8Array, CreateWith};
 use std::ptr;
 
@@ -28,7 +28,7 @@ impl TextEncoder {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<TextEncoder> {
-        reflect_dom_object(box TextEncoder::new_inherited(),
+        reflect_dom_object(Box::new(TextEncoder::new_inherited()),
                            global,
                            TextEncoderBinding::Wrap)
     }
@@ -47,12 +47,12 @@ impl TextEncoderMethods for TextEncoder {
 
     #[allow(unsafe_code)]
     // https://encoding.spec.whatwg.org/#dom-textencoder-encode
-    unsafe fn Encode(&self, cx: *mut JSContext, input: USVString) -> NonZero<*mut JSObject> {
+    unsafe fn Encode(&self, cx: *mut JSContext, input: USVString) -> NonNullJSObjectPtr {
         let encoded = input.0.as_bytes();
 
         rooted!(in(cx) let mut js_object = ptr::null_mut());
         assert!(Uint8Array::create(cx, CreateWith::Slice(&encoded), js_object.handle_mut()).is_ok());
 
-        NonZero::new_unchecked(js_object.get())
+        NonNullJSObjectPtr::new_unchecked(js_object.get())
     }
 }
diff --git a/servo/components/script/dom/touch.rs b/servo/components/script/dom/touch.rs
index e12fce6379c4..77ad2d822c5f 100644
--- a/servo/components/script/dom/touch.rs
+++ b/servo/components/script/dom/touch.rs
@@ -46,12 +46,16 @@ impl Touch {
               screen_x: Finite<f64>, screen_y: Finite<f64>,
               client_x: Finite<f64>, client_y: Finite<f64>,
               page_x: Finite<f64>, page_y: Finite<f64>) -> DomRoot<Touch> {
-        reflect_dom_object(box Touch::new_inherited(identifier, target,
-                                                    screen_x, screen_y,
-                                                    client_x, client_y,
-                                                    page_x, page_y),
-                           window,
-                           TouchBinding::Wrap)
+        reflect_dom_object(Box::new(
+            Touch::new_inherited(
+                identifier, target,
+                screen_x, screen_y,
+                client_x, client_y,
+                page_x, page_y
+            )),
+            window,
+            TouchBinding::Wrap
+        )
     }
 }
 
diff --git a/servo/components/script/dom/touchevent.rs b/servo/components/script/dom/touchevent.rs
index 6a33b7f244ee..2715454ae529 100644
--- a/servo/components/script/dom/touchevent.rs
+++ b/servo/components/script/dom/touchevent.rs
@@ -48,7 +48,7 @@ impl TouchEvent {
                      touches: &TouchList,
                      changed_touches: &TouchList,
                      target_touches: &TouchList) -> DomRoot<TouchEvent> {
-        reflect_dom_object(box TouchEvent::new_inherited(touches, changed_touches, target_touches),
+        reflect_dom_object(Box::new(TouchEvent::new_inherited(touches, changed_touches, target_touches)),
                            window,
                            TouchEventBinding::Wrap)
     }
diff --git a/servo/components/script/dom/touchlist.rs b/servo/components/script/dom/touchlist.rs
index 8881bec0faac..407a0e296d2a 100644
--- a/servo/components/script/dom/touchlist.rs
+++ b/servo/components/script/dom/touchlist.rs
@@ -25,7 +25,7 @@ impl TouchList {
     }
 
     pub fn new(window: &Window, touches: &[&Touch]) -> DomRoot<TouchList> {
-        reflect_dom_object(box TouchList::new_inherited(touches),
+        reflect_dom_object(Box::new(TouchList::new_inherited(touches)),
                            window, TouchListBinding::Wrap)
     }
 }
diff --git a/servo/components/script/dom/transitionevent.rs b/servo/components/script/dom/transitionevent.rs
index 7a3caea99ad6..3d3f25f4e7aa 100644
--- a/servo/components/script/dom/transitionevent.rs
+++ b/servo/components/script/dom/transitionevent.rs
@@ -37,7 +37,7 @@ impl TransitionEvent {
     pub fn new(window: &Window,
                type_: Atom,
                init: &TransitionEventInit) -> DomRoot<TransitionEvent> {
-        let ev = reflect_dom_object(box TransitionEvent::new_inherited(init),
+        let ev = reflect_dom_object(Box::new(TransitionEvent::new_inherited(init)),
                                     window,
                                     TransitionEventBinding::Wrap);
         {
diff --git a/servo/components/script/dom/treewalker.rs b/servo/components/script/dom/treewalker.rs
index b4cead438ffd..c1d60c5a9f68 100644
--- a/servo/components/script/dom/treewalker.rs
+++ b/servo/components/script/dom/treewalker.rs
@@ -44,7 +44,7 @@ impl TreeWalker {
                            root_node: &Node,
                            what_to_show: u32,
                            filter: Filter) -> DomRoot<TreeWalker> {
-        reflect_dom_object(box TreeWalker::new_inherited(root_node, what_to_show, filter),
+        reflect_dom_object(Box::new(TreeWalker::new_inherited(root_node, what_to_show, filter)),
                            document.window(),
                            TreeWalkerBinding::Wrap)
     }
diff --git a/servo/components/script/dom/uievent.rs b/servo/components/script/dom/uievent.rs
index 6d54a48a0cd3..1e6af67f41ec 100644
--- a/servo/components/script/dom/uievent.rs
+++ b/servo/components/script/dom/uievent.rs
@@ -35,7 +35,7 @@ impl UIEvent {
     }
 
     pub fn new_uninitialized(window: &Window) -> DomRoot<UIEvent> {
-        reflect_dom_object(box UIEvent::new_inherited(),
+        reflect_dom_object(Box::new(UIEvent::new_inherited()),
                            window,
                            UIEventBinding::Wrap)
     }
diff --git a/servo/components/script/dom/url.rs b/servo/components/script/dom/url.rs
index 9134f0cc104d..f605e717bf8e 100644
--- a/servo/components/script/dom/url.rs
+++ b/servo/components/script/dom/url.rs
@@ -43,7 +43,7 @@ impl URL {
     }
 
     pub fn new(global: &GlobalScope, url: ServoUrl) -> DomRoot<URL> {
-        reflect_dom_object(box URL::new_inherited(url),
+        reflect_dom_object(Box::new(URL::new_inherited(url)),
                            global, URLBinding::Wrap)
     }
 
diff --git a/servo/components/script/dom/urlsearchparams.rs b/servo/components/script/dom/urlsearchparams.rs
index c5eef3d7837c..a5519894c545 100644
--- a/servo/components/script/dom/urlsearchparams.rs
+++ b/servo/components/script/dom/urlsearchparams.rs
@@ -38,7 +38,7 @@ impl URLSearchParams {
     }
 
     pub fn new(global: &GlobalScope, url: Option<&URL>) -> DomRoot<URLSearchParams> {
-        reflect_dom_object(box URLSearchParams::new_inherited(url), global,
+        reflect_dom_object(Box::new(URLSearchParams::new_inherited(url)), global,
                            URLSearchParamsWrap)
     }
 
diff --git a/servo/components/script/dom/validitystate.rs b/servo/components/script/dom/validitystate.rs
index d99eba8c1095..3357c29a1759 100755
--- a/servo/components/script/dom/validitystate.rs
+++ b/servo/components/script/dom/validitystate.rs
@@ -61,7 +61,7 @@ impl ValidityState {
     }
 
     pub fn new(window: &Window, element: &Element) -> DomRoot<ValidityState> {
-        reflect_dom_object(box ValidityState::new_inherited(element),
+        reflect_dom_object(Box::new(ValidityState::new_inherited(element)),
                            window,
                            ValidityStateBinding::Wrap)
     }
diff --git a/servo/components/script/dom/vr.rs b/servo/components/script/dom/vr.rs
index d4b0429ebacc..fc3bc1c05b3c 100644
--- a/servo/components/script/dom/vr.rs
+++ b/servo/components/script/dom/vr.rs
@@ -42,9 +42,7 @@ impl VR {
     }
 
     pub fn new(global: &GlobalScope) -> DomRoot<VR> {
-        let root = reflect_dom_object(box VR::new_inherited(),
-                           global,
-                           VRBinding::Wrap);
+        let root = reflect_dom_object(Box::new(VR::new_inherited()), global, VRBinding::Wrap);
         root.register();
         root
     }
diff --git a/servo/components/script/dom/vrdisplay.rs b/servo/components/script/dom/vrdisplay.rs
index d8457d468008..4f012856c2c6 100644
--- a/servo/components/script/dom/vrdisplay.rs
+++ b/servo/components/script/dom/vrdisplay.rs
@@ -3,7 +3,6 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use canvas_traits::webgl::{webgl_channel, WebGLReceiver, WebVRCommand};
-use core::ops::Deref;
 use dom::bindings::callback::ExceptionHandling;
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::PerformanceBinding::PerformanceBinding::PerformanceMethods;
@@ -38,6 +37,7 @@ use script_runtime::CommonScriptMsg;
 use script_runtime::ScriptThreadEventCategory::WebVREvent;
 use std::cell::Cell;
 use std::mem;
+use std::ops::Deref;
 use std::rc::Rc;
 use std::sync::mpsc;
 use std::thread;
@@ -122,7 +122,7 @@ impl VRDisplay {
     }
 
     pub fn new(global: &GlobalScope, display: WebVRDisplayData) -> DomRoot<VRDisplay> {
-        reflect_dom_object(box VRDisplay::new_inherited(&global, display),
+        reflect_dom_object(Box::new(VRDisplay::new_inherited(&global, display)),
                            global,
                            VRDisplayBinding::Wrap)
     }
@@ -512,9 +512,9 @@ impl VRDisplay {
                 // Run RAF callbacks on JavaScript thread
                 let this = address.clone();
                 let sender = raf_sender.clone();
-                let task = box task!(handle_vrdisplay_raf: move || {
+                let task = Box::new(task!(handle_vrdisplay_raf: move || {
                     this.root().handle_raf(&sender);
-                });
+                }));
                 js_sender.send(CommonScriptMsg::Task(WebVREvent, task)).unwrap();
 
                 // Run Sync Poses in parallell on Render thread
diff --git a/servo/components/script/dom/vrdisplaycapabilities.rs b/servo/components/script/dom/vrdisplaycapabilities.rs
index bf16b0cbf4f1..9721de0e1b6d 100644
--- a/servo/components/script/dom/vrdisplaycapabilities.rs
+++ b/servo/components/script/dom/vrdisplaycapabilities.rs
@@ -29,7 +29,7 @@ impl VRDisplayCapabilities {
     }
 
     pub fn new(capabilities: WebVRDisplayCapabilities, global: &GlobalScope) -> DomRoot<VRDisplayCapabilities> {
-        reflect_dom_object(box VRDisplayCapabilities::new_inherited(capabilities),
+        reflect_dom_object(Box::new(VRDisplayCapabilities::new_inherited(capabilities)),
                            global,
                            VRDisplayCapabilitiesBinding::Wrap)
     }
diff --git a/servo/components/script/dom/vrdisplayevent.rs b/servo/components/script/dom/vrdisplayevent.rs
index 26072b499c5c..41ff8fd0859c 100644
--- a/servo/components/script/dom/vrdisplayevent.rs
+++ b/servo/components/script/dom/vrdisplayevent.rs
@@ -44,9 +44,11 @@ impl VRDisplayEvent {
                display: &VRDisplay,
                reason: Option<VRDisplayEventReason>)
                -> DomRoot<VRDisplayEvent> {
-        let ev = reflect_dom_object(box VRDisplayEvent::new_inherited(&display, reason),
-                           global,
-                           VRDisplayEventBinding::Wrap);
+        let ev = reflect_dom_object(
+            Box::new(VRDisplayEvent::new_inherited(&display, reason)),
+            global,
+            VRDisplayEventBinding::Wrap
+        );
         {
             let event = ev.upcast::<Event>();
             event.init_event(type_, bubbles, cancelable);
diff --git a/servo/components/script/dom/vreyeparameters.rs b/servo/components/script/dom/vreyeparameters.rs
index 5db556cdf073..f29d0230de5c 100644
--- a/servo/components/script/dom/vreyeparameters.rs
+++ b/servo/components/script/dom/vreyeparameters.rs
@@ -2,10 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use core::nonzero::NonZero;
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::VREyeParametersBinding;
 use dom::bindings::codegen::Bindings::VREyeParametersBinding::VREyeParametersMethods;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot};
 use dom::globalscope::GlobalScope;
@@ -48,7 +48,7 @@ impl VREyeParameters {
             let _ = Float32Array::create(cx, CreateWith::Slice(&parameters.offset), array.handle_mut());
         }
 
-        let eye_parameters = reflect_dom_object(box VREyeParameters::new_inherited(parameters, &fov),
+        let eye_parameters = reflect_dom_object(Box::new(VREyeParameters::new_inherited(parameters, &fov)),
                                                 global,
                                                 VREyeParametersBinding::Wrap);
         eye_parameters.offset.set(array.get());
@@ -60,8 +60,8 @@ impl VREyeParameters {
 impl VREyeParametersMethods for VREyeParameters {
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vreyeparameters-offset
-    unsafe fn Offset(&self, _cx: *mut JSContext) -> NonZero<*mut JSObject> {
-        NonZero::new_unchecked(self.offset.get())
+    unsafe fn Offset(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
+        NonNullJSObjectPtr::new_unchecked(self.offset.get())
     }
 
     // https://w3c.github.io/webvr/#dom-vreyeparameters-fieldofview
diff --git a/servo/components/script/dom/vrfieldofview.rs b/servo/components/script/dom/vrfieldofview.rs
index 389c2edeef46..3bcb80b3e2c9 100644
--- a/servo/components/script/dom/vrfieldofview.rs
+++ b/servo/components/script/dom/vrfieldofview.rs
@@ -30,7 +30,7 @@ impl VRFieldOfView {
     }
 
     pub fn new(global: &GlobalScope, fov: WebVRFieldOfView) -> DomRoot<VRFieldOfView> {
-        reflect_dom_object(box VRFieldOfView::new_inherited(fov),
+        reflect_dom_object(Box::new(VRFieldOfView::new_inherited(fov)),
                            global,
                            VRFieldOfViewBinding::Wrap)
     }
diff --git a/servo/components/script/dom/vrframedata.rs b/servo/components/script/dom/vrframedata.rs
index 4ed95a2a4b40..0c36536e4b72 100644
--- a/servo/components/script/dom/vrframedata.rs
+++ b/servo/components/script/dom/vrframedata.rs
@@ -2,10 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use core::nonzero::NonZero;
 use dom::bindings::codegen::Bindings::VRFrameDataBinding;
 use dom::bindings::codegen::Bindings::VRFrameDataBinding::VRFrameDataMethods;
 use dom::bindings::error::Fallible;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot};
@@ -53,7 +53,7 @@ impl VRFrameData {
                       0.0, 0.0, 0.0, 1.0f32];
         let pose = VRPose::new(&global, &Default::default());
 
-        let root = reflect_dom_object(box VRFrameData::new_inherited(&pose),
+        let root = reflect_dom_object(Box::new(VRFrameData::new_inherited(&pose)),
                                       global,
                                       VRFrameDataBinding::Wrap);
         let cx = global.get_cx();
@@ -118,26 +118,26 @@ impl VRFrameDataMethods for VRFrameData {
 
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vrframedata-leftprojectionmatrix
-    unsafe fn LeftProjectionMatrix(&self, _cx: *mut JSContext) -> NonZero<*mut JSObject> {
-        NonZero::new_unchecked(self.left_proj.get())
+    unsafe fn LeftProjectionMatrix(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
+        NonNullJSObjectPtr::new_unchecked(self.left_proj.get())
     }
 
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vrframedata-leftviewmatrix
-    unsafe fn LeftViewMatrix(&self, _cx: *mut JSContext) -> NonZero<*mut JSObject> {
-        NonZero::new_unchecked(self.left_view.get())
+    unsafe fn LeftViewMatrix(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
+        NonNullJSObjectPtr::new_unchecked(self.left_view.get())
     }
 
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vrframedata-rightprojectionmatrix
-    unsafe fn RightProjectionMatrix(&self, _cx: *mut JSContext) -> NonZero<*mut JSObject> {
-        NonZero::new_unchecked(self.right_proj.get())
+    unsafe fn RightProjectionMatrix(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
+        NonNullJSObjectPtr::new_unchecked(self.right_proj.get())
     }
 
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vrframedata-rightviewmatrix
-    unsafe fn RightViewMatrix(&self, _cx: *mut JSContext) -> NonZero<*mut JSObject> {
-        NonZero::new_unchecked(self.right_view.get())
+    unsafe fn RightViewMatrix(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
+        NonNullJSObjectPtr::new_unchecked(self.right_view.get())
     }
 
     // https://w3c.github.io/webvr/#dom-vrframedata-pose
diff --git a/servo/components/script/dom/vrpose.rs b/servo/components/script/dom/vrpose.rs
index d80a4c5a0498..b6a9fad10a0b 100644
--- a/servo/components/script/dom/vrpose.rs
+++ b/servo/components/script/dom/vrpose.rs
@@ -2,9 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use core::nonzero::NonZero;
 use dom::bindings::codegen::Bindings::VRPoseBinding;
 use dom::bindings::codegen::Bindings::VRPoseBinding::VRPoseMethods;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
 use dom::globalscope::GlobalScope;
@@ -52,13 +52,13 @@ unsafe fn update_or_create_typed_array(cx: *mut JSContext,
 
 #[inline]
 #[allow(unsafe_code)]
-fn heap_to_option(heap: &Heap<*mut JSObject>) -> Option<NonZero<*mut JSObject>> {
+fn heap_to_option(heap: &Heap<*mut JSObject>) -> Option<NonNullJSObjectPtr> {
     let js_object = heap.get();
     if js_object.is_null() {
         None
     } else {
         unsafe {
-            Some(NonZero::new_unchecked(js_object))
+            Some(NonNullJSObjectPtr::new_unchecked(js_object))
         }
     }
 }
@@ -77,7 +77,7 @@ impl VRPose {
     }
 
     pub fn new(global: &GlobalScope, pose: &webvr::VRPose) -> DomRoot<VRPose> {
-        let root = reflect_dom_object(box VRPose::new_inherited(),
+        let root = reflect_dom_object(Box::new(VRPose::new_inherited()),
                                       global,
                                       VRPoseBinding::Wrap);
         root.update(&pose);
@@ -101,37 +101,37 @@ impl VRPose {
 impl VRPoseMethods for VRPose {
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vrpose-position
-    unsafe fn GetPosition(&self, _cx: *mut JSContext) -> Option<NonZero<*mut JSObject>> {
+    unsafe fn GetPosition(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
         heap_to_option(&self.position)
     }
 
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vrpose-linearvelocity
-    unsafe fn GetLinearVelocity(&self, _cx: *mut JSContext) -> Option<NonZero<*mut JSObject>> {
+    unsafe fn GetLinearVelocity(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
         heap_to_option(&self.linear_vel)
     }
 
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vrpose-linearacceleration
-    unsafe fn GetLinearAcceleration(&self, _cx: *mut JSContext) -> Option<NonZero<*mut JSObject>> {
+    unsafe fn GetLinearAcceleration(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
         heap_to_option(&self.linear_acc)
     }
 
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vrpose-orientation
-    unsafe fn GetOrientation(&self, _cx: *mut JSContext) -> Option<NonZero<*mut JSObject>> {
+    unsafe fn GetOrientation(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
         heap_to_option(&self.orientation)
     }
 
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vrpose-angularvelocity
-    unsafe fn GetAngularVelocity(&self, _cx: *mut JSContext) -> Option<NonZero<*mut JSObject>> {
+    unsafe fn GetAngularVelocity(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
         heap_to_option(&self.angular_vel)
     }
 
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vrpose-angularacceleration
-    unsafe fn GetAngularAcceleration(&self, _cx: *mut JSContext) -> Option<NonZero<*mut JSObject>> {
+    unsafe fn GetAngularAcceleration(&self, _cx: *mut JSContext) -> Option<NonNullJSObjectPtr> {
         heap_to_option(&self.angular_acc)
     }
 }
diff --git a/servo/components/script/dom/vrstageparameters.rs b/servo/components/script/dom/vrstageparameters.rs
index d7287249a89c..a2a185fd6ccd 100644
--- a/servo/components/script/dom/vrstageparameters.rs
+++ b/servo/components/script/dom/vrstageparameters.rs
@@ -2,10 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use core::nonzero::NonZero;
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::VRStageParametersBinding;
 use dom::bindings::codegen::Bindings::VRStageParametersBinding::VRStageParametersMethods;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::num::Finite;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::DomRoot;
@@ -44,7 +44,7 @@ impl VRStageParameters {
                                                                array.handle_mut());
         }
 
-        let stage_parameters  = reflect_dom_object(box VRStageParameters::new_inherited(parameters),
+        let stage_parameters  = reflect_dom_object(Box::new(VRStageParameters::new_inherited(parameters)),
                                                    global,
                                                    VRStageParametersBinding::Wrap);
 
@@ -69,8 +69,8 @@ impl VRStageParameters {
 impl VRStageParametersMethods for VRStageParameters {
     #[allow(unsafe_code)]
     // https://w3c.github.io/webvr/#dom-vrstageparameters-sittingtostandingtransform
-    unsafe fn SittingToStandingTransform(&self, _cx: *mut JSContext) -> NonZero<*mut JSObject> {
-        NonZero::new_unchecked(self.transform.get())
+    unsafe fn SittingToStandingTransform(&self, _cx: *mut JSContext) -> NonNullJSObjectPtr {
+        NonNullJSObjectPtr::new_unchecked(self.transform.get())
     }
 
     // https://w3c.github.io/webvr/#dom-vrstageparameters-sizex
diff --git a/servo/components/script/dom/webgl_extensions/ext/oesstandardderivatives.rs b/servo/components/script/dom/webgl_extensions/ext/oesstandardderivatives.rs
index 3740db147513..6ede450e6210 100644
--- a/servo/components/script/dom/webgl_extensions/ext/oesstandardderivatives.rs
+++ b/servo/components/script/dom/webgl_extensions/ext/oesstandardderivatives.rs
@@ -26,7 +26,7 @@ impl OESStandardDerivatives {
 impl WebGLExtension for OESStandardDerivatives {
     type Extension = OESStandardDerivatives;
     fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESStandardDerivatives> {
-        reflect_dom_object(box OESStandardDerivatives::new_inherited(),
+        reflect_dom_object(Box::new(OESStandardDerivatives::new_inherited()),
                            &*ctx.global(),
                            OESStandardDerivativesBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webgl_extensions/ext/oestexturefloat.rs b/servo/components/script/dom/webgl_extensions/ext/oestexturefloat.rs
index 967df546cc9c..532339058571 100644
--- a/servo/components/script/dom/webgl_extensions/ext/oestexturefloat.rs
+++ b/servo/components/script/dom/webgl_extensions/ext/oestexturefloat.rs
@@ -25,7 +25,7 @@ impl OESTextureFloat {
 impl WebGLExtension for OESTextureFloat {
     type Extension = OESTextureFloat;
     fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESTextureFloat> {
-        reflect_dom_object(box OESTextureFloat::new_inherited(),
+        reflect_dom_object(Box::new(OESTextureFloat::new_inherited()),
                            &*ctx.global(),
                            OESTextureFloatBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webgl_extensions/ext/oestexturefloatlinear.rs b/servo/components/script/dom/webgl_extensions/ext/oestexturefloatlinear.rs
index 2a730f2e85fd..ec7a02b34bb0 100644
--- a/servo/components/script/dom/webgl_extensions/ext/oestexturefloatlinear.rs
+++ b/servo/components/script/dom/webgl_extensions/ext/oestexturefloatlinear.rs
@@ -25,7 +25,7 @@ impl OESTextureFloatLinear {
 impl WebGLExtension for OESTextureFloatLinear {
     type Extension = OESTextureFloatLinear;
     fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESTextureFloatLinear> {
-        reflect_dom_object(box OESTextureFloatLinear::new_inherited(),
+        reflect_dom_object(Box::new(OESTextureFloatLinear::new_inherited()),
                            &*ctx.global(),
                            OESTextureFloatLinearBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webgl_extensions/ext/oestexturehalffloat.rs b/servo/components/script/dom/webgl_extensions/ext/oestexturehalffloat.rs
index f5db59e097df..a9e32c7a8f5b 100644
--- a/servo/components/script/dom/webgl_extensions/ext/oestexturehalffloat.rs
+++ b/servo/components/script/dom/webgl_extensions/ext/oestexturehalffloat.rs
@@ -25,7 +25,7 @@ impl OESTextureHalfFloat {
 impl WebGLExtension for OESTextureHalfFloat {
     type Extension = OESTextureHalfFloat;
     fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESTextureHalfFloat> {
-        reflect_dom_object(box OESTextureHalfFloat::new_inherited(),
+        reflect_dom_object(Box::new(OESTextureHalfFloat::new_inherited()),
                            &*ctx.global(),
                            OESTextureHalfFloatBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webgl_extensions/ext/oestexturehalffloatlinear.rs b/servo/components/script/dom/webgl_extensions/ext/oestexturehalffloatlinear.rs
index 52f15ada5c2d..a94702321eba 100644
--- a/servo/components/script/dom/webgl_extensions/ext/oestexturehalffloatlinear.rs
+++ b/servo/components/script/dom/webgl_extensions/ext/oestexturehalffloatlinear.rs
@@ -26,7 +26,7 @@ impl OESTextureHalfFloatLinear {
 impl WebGLExtension for OESTextureHalfFloatLinear {
     type Extension = OESTextureHalfFloatLinear;
     fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESTextureHalfFloatLinear> {
-        reflect_dom_object(box OESTextureHalfFloatLinear::new_inherited(),
+        reflect_dom_object(Box::new(OESTextureHalfFloatLinear::new_inherited()),
                            &*ctx.global(),
                            OESTextureHalfFloatLinearBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webgl_extensions/ext/oesvertexarrayobject.rs b/servo/components/script/dom/webgl_extensions/ext/oesvertexarrayobject.rs
index cf2f3ab0f506..9ba3f4709abb 100644
--- a/servo/components/script/dom/webgl_extensions/ext/oesvertexarrayobject.rs
+++ b/servo/components/script/dom/webgl_extensions/ext/oesvertexarrayobject.rs
@@ -133,7 +133,7 @@ impl OESVertexArrayObjectMethods for OESVertexArrayObject {
 impl WebGLExtension for OESVertexArrayObject {
     type Extension = OESVertexArrayObject;
     fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESVertexArrayObject> {
-        reflect_dom_object(box OESVertexArrayObject::new_inherited(ctx),
+        reflect_dom_object(Box::new(OESVertexArrayObject::new_inherited(ctx)),
                            &*ctx.global(),
                            OESVertexArrayObjectBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webgl_extensions/ext/webglvertexarrayobjectoes.rs b/servo/components/script/dom/webgl_extensions/ext/webglvertexarrayobjectoes.rs
index 8433b3453281..4ca8c7b7adde 100644
--- a/servo/components/script/dom/webgl_extensions/ext/webglvertexarrayobjectoes.rs
+++ b/servo/components/script/dom/webgl_extensions/ext/webglvertexarrayobjectoes.rs
@@ -3,8 +3,6 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use canvas_traits::webgl::WebGLVertexArrayId;
-use core::cell::Ref;
-use core::iter::FromIterator;
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::WebGLVertexArrayObjectOESBinding;
 use dom::bindings::reflector::reflect_dom_object;
@@ -13,8 +11,9 @@ use dom::globalscope::GlobalScope;
 use dom::webglbuffer::WebGLBuffer;
 use dom::webglobject::WebGLObject;
 use dom_struct::dom_struct;
-use std::cell::Cell;
+use std::cell::{Cell, Ref};
 use std::collections::HashMap;
+use std::iter::FromIterator;
 
 #[dom_struct]
 pub struct WebGLVertexArrayObjectOES {
@@ -39,7 +38,7 @@ impl WebGLVertexArrayObjectOES {
     }
 
     pub fn new(global: &GlobalScope, id: WebGLVertexArrayId) -> DomRoot<WebGLVertexArrayObjectOES> {
-        reflect_dom_object(box WebGLVertexArrayObjectOES::new_inherited(id),
+        reflect_dom_object(Box::new(WebGLVertexArrayObjectOES::new_inherited(id)),
                            global,
                            WebGLVertexArrayObjectOESBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webgl_extensions/extensions.rs b/servo/components/script/dom/webgl_extensions/extensions.rs
index 8f340b7835d8..9b022ac7defc 100644
--- a/servo/components/script/dom/webgl_extensions/extensions.rs
+++ b/servo/components/script/dom/webgl_extensions/extensions.rs
@@ -3,23 +3,23 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use canvas_traits::webgl::WebGLError;
-use core::iter::FromIterator;
-use core::nonzero::NonZero;
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::OESStandardDerivativesBinding::OESStandardDerivativesConstants;
 use dom::bindings::codegen::Bindings::OESTextureHalfFloatBinding::OESTextureHalfFloatConstants;
 use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::root::DomRoot;
 use dom::bindings::trace::JSTraceable;
 use dom::webglrenderingcontext::WebGLRenderingContext;
 use fnv::{FnvHashMap, FnvHashSet};
 use gleam::gl::GLenum;
 use heapsize::HeapSizeOf;
-use js::jsapi::{JSContext, JSObject};
+use js::jsapi::JSContext;
 use js::jsval::JSVal;
 use ref_filter_map::ref_filter_map;
 use std::cell::Ref;
 use std::collections::HashMap;
+use std::iter::FromIterator;
 use super::{ext, WebGLExtension};
 use super::wrapper::{WebGLExtensionWrapper, TypedWebGLExtensionWrapper};
 
@@ -99,7 +99,7 @@ impl WebGLExtensions {
 
     pub fn register<T:'static + WebGLExtension + JSTraceable + HeapSizeOf>(&self) {
         let name = T::name().to_uppercase();
-        self.extensions.borrow_mut().insert(name, box TypedWebGLExtensionWrapper::<T>::new());
+        self.extensions.borrow_mut().insert(name, Box::new(TypedWebGLExtensionWrapper::<T>::new()));
     }
 
     pub fn get_suported_extensions(&self) -> Vec<&'static str> {
@@ -109,7 +109,7 @@ impl WebGLExtensions {
                                 .collect()
     }
 
-    pub fn get_or_init_extension(&self, name: &str, ctx: &WebGLRenderingContext) -> Option<NonZero<*mut JSObject>> {
+    pub fn get_or_init_extension(&self, name: &str, ctx: &WebGLRenderingContext) -> Option<NonNullJSObjectPtr> {
         let name = name.to_uppercase();
         self.extensions.borrow().get(&name).and_then(|extension| {
             if extension.is_supported(self) {
diff --git a/servo/components/script/dom/webgl_extensions/wrapper.rs b/servo/components/script/dom/webgl_extensions/wrapper.rs
index 7b4452ad7dc8..49d698bf14ca 100644
--- a/servo/components/script/dom/webgl_extensions/wrapper.rs
+++ b/servo/components/script/dom/webgl_extensions/wrapper.rs
@@ -2,13 +2,12 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use core::nonzero::NonZero;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::DomObject;
 use dom::bindings::root::{DomRoot, MutNullableDom};
 use dom::bindings::trace::JSTraceable;
 use dom::webglrenderingcontext::WebGLRenderingContext;
 use heapsize::HeapSizeOf;
-use js::jsapi::JSObject;
 use std::any::Any;
 use super::{WebGLExtension, WebGLExtensions};
 
@@ -18,7 +17,7 @@ pub trait WebGLExtensionWrapper: JSTraceable + HeapSizeOf {
     fn instance_or_init(&self,
                         ctx: &WebGLRenderingContext,
                         ext: &WebGLExtensions)
-                        -> NonZero<*mut JSObject>;
+                        -> NonNullJSObjectPtr;
     fn is_supported(&self, &WebGLExtensions) -> bool;
     fn is_enabled(&self) -> bool;
     fn enable(&self, ext: &WebGLExtensions);
@@ -48,7 +47,7 @@ impl<T> WebGLExtensionWrapper for TypedWebGLExtensionWrapper<T>
     fn instance_or_init(&self,
                         ctx: &WebGLRenderingContext,
                         ext: &WebGLExtensions)
-                        -> NonZero<*mut JSObject> {
+                        -> NonNullJSObjectPtr {
         let mut enabled = true;
         let extension = self.extension.or_init(|| {
             enabled = false;
@@ -58,7 +57,7 @@ impl<T> WebGLExtensionWrapper for TypedWebGLExtensionWrapper<T>
             self.enable(ext);
         }
         unsafe {
-            NonZero::new_unchecked(extension.reflector().get_jsobject().get())
+            NonNullJSObjectPtr::new_unchecked(extension.reflector().get_jsobject().get())
         }
     }
 
diff --git a/servo/components/script/dom/webglactiveinfo.rs b/servo/components/script/dom/webglactiveinfo.rs
index 6712e61fea4e..245f61941051 100644
--- a/servo/components/script/dom/webglactiveinfo.rs
+++ b/servo/components/script/dom/webglactiveinfo.rs
@@ -31,7 +31,11 @@ impl WebGLActiveInfo {
     }
 
     pub fn new(window: &Window, size: i32, ty: u32, name: DOMString) -> DomRoot<WebGLActiveInfo> {
-        reflect_dom_object(box WebGLActiveInfo::new_inherited(size, ty, name), window, WebGLActiveInfoBinding::Wrap)
+        reflect_dom_object(
+            Box::new(WebGLActiveInfo::new_inherited(size, ty, name)),
+            window,
+            WebGLActiveInfoBinding::Wrap
+        )
     }
 }
 
diff --git a/servo/components/script/dom/webglbuffer.rs b/servo/components/script/dom/webglbuffer.rs
index 4510a74fd1b2..fc916f99a6cd 100644
--- a/servo/components/script/dom/webglbuffer.rs
+++ b/servo/components/script/dom/webglbuffer.rs
@@ -60,7 +60,7 @@ impl WebGLBuffer {
                renderer: WebGLMsgSender,
                id: WebGLBufferId)
               -> DomRoot<WebGLBuffer> {
-        reflect_dom_object(box WebGLBuffer::new_inherited(renderer, id),
+        reflect_dom_object(Box::new(WebGLBuffer::new_inherited(renderer, id)),
                            window, WebGLBufferBinding::Wrap)
     }
 }
diff --git a/servo/components/script/dom/webglcontextevent.rs b/servo/components/script/dom/webglcontextevent.rs
index 3e28af76d6e1..aeec60f8cf19 100644
--- a/servo/components/script/dom/webglcontextevent.rs
+++ b/servo/components/script/dom/webglcontextevent.rs
@@ -48,7 +48,7 @@ impl WebGLContextEvent {
         // available.
         let status_message = DOMString::new();
         reflect_dom_object(
-                        box WebGLContextEvent::new_inherited(status_message),
+                        Box::new(WebGLContextEvent::new_inherited(status_message)),
                         window,
                         WebGLContextEventBinding::Wrap)
     }
@@ -59,7 +59,7 @@ impl WebGLContextEvent {
                cancelable: EventCancelable,
                status_message: DOMString) -> DomRoot<WebGLContextEvent> {
         let event = reflect_dom_object(
-                        box WebGLContextEvent::new_inherited(status_message),
+                        Box::new(WebGLContextEvent::new_inherited(status_message)),
                         window,
                         WebGLContextEventBinding::Wrap);
 
diff --git a/servo/components/script/dom/webglframebuffer.rs b/servo/components/script/dom/webglframebuffer.rs
index 211a4a5d8b90..1fcfbf83f515 100644
--- a/servo/components/script/dom/webglframebuffer.rs
+++ b/servo/components/script/dom/webglframebuffer.rs
@@ -77,7 +77,7 @@ impl WebGLFramebuffer {
                renderer: WebGLMsgSender,
                id: WebGLFramebufferId)
                -> DomRoot<WebGLFramebuffer> {
-        reflect_dom_object(box WebGLFramebuffer::new_inherited(renderer, id),
+        reflect_dom_object(Box::new(WebGLFramebuffer::new_inherited(renderer, id)),
                            window,
                            WebGLFramebufferBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webglprogram.rs b/servo/components/script/dom/webglprogram.rs
index 50c61397bb85..58b4b51f6456 100644
--- a/servo/components/script/dom/webglprogram.rs
+++ b/servo/components/script/dom/webglprogram.rs
@@ -60,7 +60,7 @@ impl WebGLProgram {
                renderer: WebGLMsgSender,
                id: WebGLProgramId)
                -> DomRoot<WebGLProgram> {
-        reflect_dom_object(box WebGLProgram::new_inherited(renderer, id),
+        reflect_dom_object(Box::new(WebGLProgram::new_inherited(renderer, id)),
                            window,
                            WebGLProgramBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webglrenderbuffer.rs b/servo/components/script/dom/webglrenderbuffer.rs
index 89151a07f8de..c1cc99955b4f 100644
--- a/servo/components/script/dom/webglrenderbuffer.rs
+++ b/servo/components/script/dom/webglrenderbuffer.rs
@@ -53,7 +53,7 @@ impl WebGLRenderbuffer {
                renderer: WebGLMsgSender,
                id: WebGLRenderbufferId)
                -> DomRoot<WebGLRenderbuffer> {
-        reflect_dom_object(box WebGLRenderbuffer::new_inherited(renderer, id),
+        reflect_dom_object(Box::new(WebGLRenderbuffer::new_inherited(renderer, id)),
                            window,
                            WebGLRenderbufferBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webglrenderingcontext.rs b/servo/components/script/dom/webglrenderingcontext.rs
index 30375b53c3f4..98076fa4889c 100644
--- a/servo/components/script/dom/webglrenderingcontext.rs
+++ b/servo/components/script/dom/webglrenderingcontext.rs
@@ -6,11 +6,9 @@ use byteorder::{NativeEndian, ReadBytesExt, WriteBytesExt};
 use canvas_traits::canvas::{byte_swap, multiply_u8_pixel};
 use canvas_traits::webgl::{WebGLContextShareMode, WebGLCommand, WebGLError};
 use canvas_traits::webgl::{WebGLFramebufferBindingRequest, WebGLMsg, WebGLMsgSender, WebGLParameter, WebVRCommand};
+use canvas_traits::webgl::DOMToTextureCommand;
 use canvas_traits::webgl::WebGLError::*;
 use canvas_traits::webgl::webgl_channel;
-use core::cell::Ref;
-use core::iter::FromIterator;
-use core::nonzero::NonZero;
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::{self, WebGLContextAttributes};
 use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
@@ -19,12 +17,14 @@ use dom::bindings::codegen::UnionTypes::ImageDataOrHTMLImageElementOrHTMLCanvasE
 use dom::bindings::conversions::{ConversionResult, FromJSValConvertible, ToJSValConvertible};
 use dom::bindings::error::{Error, Fallible};
 use dom::bindings::inheritance::Castable;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot, LayoutDom, MutNullableDom};
 use dom::bindings::str::DOMString;
 use dom::event::{Event, EventBubbles, EventCancelable};
 use dom::htmlcanvaselement::HTMLCanvasElement;
 use dom::htmlcanvaselement::utils as canvas_utils;
+use dom::htmliframeelement::HTMLIFrameElement;
 use dom::node::{Node, NodeDamage, window_from_node};
 use dom::webgl_extensions::WebGLExtensions;
 use dom::webgl_validations::WebGLValidator;
@@ -55,7 +55,8 @@ use net_traits::image_cache::ImageResponse;
 use offscreen_gl_context::{GLContextAttributes, GLLimits};
 use script_layout_interface::HTMLCanvasDataSource;
 use servo_config::prefs::PREFS;
-use std::cell::Cell;
+use std::cell::{Cell, Ref};
+use std::iter::FromIterator;
 use webrender_api;
 
 type ImagePixelResult = Result<(Vec<u8>, Size2D<i32>, bool), ()>;
@@ -256,7 +257,7 @@ impl WebGLRenderingContext {
     pub fn new(window: &Window, canvas: &HTMLCanvasElement, size: Size2D<i32>, attrs: GLContextAttributes)
                -> Option<DomRoot<WebGLRenderingContext>> {
         match WebGLRenderingContext::new_inherited(window, canvas, size, attrs) {
-            Ok(ctx) => Some(reflect_dom_object(box ctx, window, WebGLRenderingContextBinding::Wrap)),
+            Ok(ctx) => Some(reflect_dom_object(Box::new(ctx), window, WebGLRenderingContextBinding::Wrap)),
             Err(msg) => {
                 error!("Couldn't create WebGLRenderingContext: {}", msg);
                 let event = WebGLContextEvent::new(window,
@@ -1377,7 +1378,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     #[allow(unsafe_code)]
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.14
     unsafe fn GetExtension(&self, _cx: *mut JSContext, name: DOMString)
-                    -> Option<NonZero<*mut JSObject>> {
+                    -> Option<NonNullJSObjectPtr> {
         self.extension_manager.init_once(|| {
             self.get_gl_extensions()
         });
@@ -3260,6 +3261,45 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
         Ok(())
     }
 
+    // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.8
+    fn TexImageDOM(&self,
+                   target: u32,
+                   level: i32,
+                   internal_format: u32,
+                   width: i32,
+                   height: i32,
+                   format: u32,
+                   data_type: u32,
+                   source: &HTMLIFrameElement) -> Fallible<()> {
+        // Currently DOMToTexture only supports TEXTURE_2D, RGBA, UNSIGNED_BYTE and no levels.
+        if target != constants::TEXTURE_2D || level != 0 || internal_format != constants::RGBA ||
+            format != constants::RGBA || data_type != constants::UNSIGNED_BYTE {
+            return Ok(self.webgl_error(InvalidValue));
+        }
+
+        // Get bound texture
+        let texture = match self.bound_texture(constants::TEXTURE_2D) {
+            Some(texture) => texture,
+            None => {
+                return Ok(self.webgl_error(InvalidOperation));
+            }
+        };
+
+        let pipeline_id = source.pipeline_id().ok_or(Error::InvalidState)?;
+        let document_id  = self.global().downcast::<Window>().ok_or(Error::InvalidState)?.webrender_document();
+
+        texture.set_attached_to_dom();
+
+        let command = DOMToTextureCommand::Attach(self.webgl_sender.context_id(),
+                                                  texture.id(),
+                                                  document_id,
+                                                  pipeline_id.to_webrender(),
+                                                  Size2D::new(width, height));
+        self.webgl_sender.send_dom_to_texture(command).unwrap();
+
+        Ok(())
+    }
+
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.8
     #[allow(unsafe_code)]
     unsafe fn TexSubImage2D(&self,
diff --git a/servo/components/script/dom/webglshader.rs b/servo/components/script/dom/webglshader.rs
index 2a48ca21e73a..d2060b1756c3 100644
--- a/servo/components/script/dom/webglshader.rs
+++ b/servo/components/script/dom/webglshader.rs
@@ -82,7 +82,7 @@ impl WebGLShader {
                id: WebGLShaderId,
                shader_type: u32)
                -> DomRoot<WebGLShader> {
-        reflect_dom_object(box WebGLShader::new_inherited(renderer, id, shader_type),
+        reflect_dom_object(Box::new(WebGLShader::new_inherited(renderer, id, shader_type)),
                            window,
                            WebGLShaderBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webglshaderprecisionformat.rs b/servo/components/script/dom/webglshaderprecisionformat.rs
index 5ea5d8e83cf9..17f32c8375df 100644
--- a/servo/components/script/dom/webglshaderprecisionformat.rs
+++ b/servo/components/script/dom/webglshaderprecisionformat.rs
@@ -35,7 +35,7 @@ impl WebGLShaderPrecisionFormat {
                range_max: i32,
                precision: i32) -> DomRoot<WebGLShaderPrecisionFormat> {
         reflect_dom_object(
-            box WebGLShaderPrecisionFormat::new_inherited(range_min, range_max, precision),
+            Box::new(WebGLShaderPrecisionFormat::new_inherited(range_min, range_max, precision)),
             window,
             WebGLShaderPrecisionFormatBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webgltexture.rs b/servo/components/script/dom/webgltexture.rs
index ec8dee281720..6927fd10a481 100644
--- a/servo/components/script/dom/webgltexture.rs
+++ b/servo/components/script/dom/webgltexture.rs
@@ -5,6 +5,7 @@
 // https://www.khronos.org/registry/webgl/specs/latest/1.0/webgl.idl
 
 use canvas_traits::webgl::{webgl_channel, WebGLCommand, WebGLError, WebGLMsgSender, WebGLResult, WebGLTextureId};
+use canvas_traits::webgl::DOMToTextureCommand;
 use dom::bindings::cell::DomRefCell;
 use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
 use dom::bindings::codegen::Bindings::WebGLTextureBinding;
@@ -45,6 +46,8 @@ pub struct WebGLTexture {
     mag_filter: Cell<Option<u32>>,
     #[ignore_heap_size_of = "Defined in ipc-channel"]
     renderer: WebGLMsgSender,
+    /// True if this texture is used for the DOMToTexture feature.
+    attached_to_dom: Cell<bool>,
 }
 
 impl WebGLTexture {
@@ -62,6 +65,7 @@ impl WebGLTexture {
             mag_filter: Cell::new(None),
             image_info_array: DomRefCell::new([ImageInfo::new(); MAX_LEVEL_COUNT * MAX_FACE_COUNT]),
             renderer: renderer,
+            attached_to_dom: Cell::new(false),
         }
     }
 
@@ -78,7 +82,7 @@ impl WebGLTexture {
                renderer: WebGLMsgSender,
                id: WebGLTextureId)
                -> DomRoot<WebGLTexture> {
-        reflect_dom_object(box WebGLTexture::new_inherited(renderer, id),
+        reflect_dom_object(Box::new(WebGLTexture::new_inherited(renderer, id)),
                            window,
                            WebGLTextureBinding::Wrap)
     }
@@ -179,6 +183,10 @@ impl WebGLTexture {
     pub fn delete(&self) {
         if !self.is_deleted.get() {
             self.is_deleted.set(true);
+            // Notify WR to release the frame output when using DOMToTexture feature
+            if self.attached_to_dom.get() {
+                let _ = self.renderer.send_dom_to_texture(DOMToTextureCommand::Detach(self.id));
+            }
             let _ = self.renderer.send(WebGLCommand::DeleteTexture(self.id));
         }
     }
@@ -374,6 +382,10 @@ impl WebGLTexture {
 
         Some(self.image_info_at_face(0, self.base_mipmap_level))
     }
+
+    pub fn set_attached_to_dom(&self) {
+        self.attached_to_dom.set(true);
+    }
 }
 
 impl Drop for WebGLTexture {
diff --git a/servo/components/script/dom/webgluniformlocation.rs b/servo/components/script/dom/webgluniformlocation.rs
index 080dda92d8b6..45662a446d3f 100644
--- a/servo/components/script/dom/webgluniformlocation.rs
+++ b/servo/components/script/dom/webgluniformlocation.rs
@@ -32,7 +32,7 @@ impl WebGLUniformLocation {
                id: i32,
                program_id: WebGLProgramId)
                -> DomRoot<WebGLUniformLocation> {
-        reflect_dom_object(box WebGLUniformLocation::new_inherited(id, program_id),
+        reflect_dom_object(Box::new(WebGLUniformLocation::new_inherited(id, program_id)),
                            window,
                            WebGLUniformLocationBinding::Wrap)
     }
diff --git a/servo/components/script/dom/webidls/WebGLRenderingContext.webidl b/servo/components/script/dom/webidls/WebGLRenderingContext.webidl
index 885ad9486bb3..ec729d1b5fbd 100644
--- a/servo/components/script/dom/webidls/WebGLRenderingContext.webidl
+++ b/servo/components/script/dom/webidls/WebGLRenderingContext.webidl
@@ -654,6 +654,9 @@ interface WebGLRenderingContextBase
     [Throws]
     void texImage2D(GLenum target, GLint level, GLenum internalformat,
                     GLenum format, GLenum type, TexImageSource? source); // May throw DOMException
+    [Throws, Pref="dom.webgl.dom_to_texture.enabled"]
+    void texImageDOM(GLenum target, GLint level, GLenum internalformat, GLsizei width, GLsizei height,
+                     GLenum format, GLenum type, HTMLIFrameElement source); // May throw DOMException
 
     void texParameterf(GLenum target, GLenum pname, GLfloat param);
     void texParameteri(GLenum target, GLenum pname, GLint param);
diff --git a/servo/components/script/dom/websocket.rs b/servo/components/script/dom/websocket.rs
index 49a77dd3db5d..e97f8ff0cf0a 100644
--- a/servo/components/script/dom/websocket.rs
+++ b/servo/components/script/dom/websocket.rs
@@ -125,7 +125,7 @@ impl WebSocket {
     }
 
     fn new(global: &GlobalScope, url: ServoUrl) -> DomRoot<WebSocket> {
-        reflect_dom_object(box WebSocket::new_inherited(url),
+        reflect_dom_object(Box::new(WebSocket::new_inherited(url)),
                            global, WebSocketBinding::Wrap)
     }
 
@@ -259,9 +259,9 @@ impl WebSocket {
         if !self.clearing_buffer.get() && self.ready_state.get() == WebSocketRequestState::Open {
             self.clearing_buffer.set(true);
 
-            let task = box BufferedAmountTask {
+            let task = Box::new(BufferedAmountTask {
                 address: address,
-            };
+            });
 
             self.global()
                 .script_chan()
diff --git a/servo/components/script/dom/window.rs b/servo/components/script/dom/window.rs
index ed8e7cf9f49e..1f8e32820642 100644
--- a/servo/components/script/dom/window.rs
+++ b/servo/components/script/dom/window.rs
@@ -123,7 +123,7 @@ use timers::{IsInterval, TimerCallback};
 use tinyfiledialogs::{self, MessageBoxIcon};
 use url::Position;
 use webdriver_handlers::jsval_to_webdriver;
-use webrender_api::ClipId;
+use webrender_api::{ClipId, DocumentId};
 use webvr_traits::WebVRMsg;
 
 /// Current state of the window object
@@ -289,6 +289,9 @@ pub struct Window {
     test_worklet: MutNullableDom<Worklet>,
     /// https://drafts.css-houdini.org/css-paint-api-1/#paint-worklet
     paint_worklet: MutNullableDom<Worklet>,
+    /// The Webrender Document id associated with this window.
+    #[ignore_heap_size_of = "defined in webrender_api"]
+    webrender_document: DocumentId,
 }
 
 impl Window {
@@ -344,7 +347,7 @@ impl Window {
 
     pub fn new_script_pair(&self) -> (Box<ScriptChan + Send>, Box<ScriptPort + Send>) {
         let (tx, rx) = channel();
-        (box SendableMainThreadScriptChan(tx), box rx)
+        (Box::new(SendableMainThreadScriptChan(tx)), Box::new(rx))
     }
 
     pub fn image_cache(&self) -> Arc<ImageCache> {
@@ -805,6 +808,7 @@ impl WindowMethods for Window {
 
     #[allow(unsafe_code)]
     fn Trap(&self) {
+        #[cfg(feature = "unstable")]
         unsafe { ::std::intrinsics::breakpoint() }
     }
 
@@ -1297,9 +1301,9 @@ impl Window {
                 let (responder, responder_listener) = ipc::channel().unwrap();
                 let pipeline = self.upcast::<GlobalScope>().pipeline_id();
                 let image_cache_chan = self.image_cache_chan.clone();
-                ROUTER.add_route(responder_listener.to_opaque(), box move |message| {
+                ROUTER.add_route(responder_listener.to_opaque(), Box::new(move |message| {
                     let _ = image_cache_chan.send((pipeline, message.to().unwrap()));
-                });
+                }));
                 self.image_cache.add_listener(id, ImageResponder::new(responder, id));
                 nodes.push(Dom::from_ref(&*node));
             }
@@ -1760,6 +1764,10 @@ impl Window {
             .send(msg)
             .unwrap();
     }
+
+    pub fn webrender_document(&self) -> DocumentId {
+        self.webrender_document
+    }
 }
 
 impl Window {
@@ -1794,6 +1802,7 @@ impl Window {
         webgl_chan: WebGLChan,
         webvr_chan: Option<IpcSender<WebVRMsg>>,
         microtask_queue: Rc<MicrotaskQueue>,
+        webrender_document: DocumentId,
     ) -> DomRoot<Self> {
         let layout_rpc: Box<LayoutRPC + Send> = {
             let (rpc_send, rpc_recv) = channel();
@@ -1804,7 +1813,7 @@ impl Window {
             pipelineid,
             script_chan: Arc::new(Mutex::new(control_chan)),
         };
-        let win = box Self {
+        let win = Box::new(Self {
             globalscope: GlobalScope::new_inherited(
                 pipelineid,
                 devtools_chan,
@@ -1868,7 +1877,8 @@ impl Window {
             unminified_js_dir: Default::default(),
             test_worklet: Default::default(),
             paint_worklet: Default::default(),
-        };
+            webrender_document,
+        });
 
         unsafe {
             WindowBinding::Wrap(runtime.cx(), win)
@@ -1982,7 +1992,7 @@ impl Window {
         // TODO(#12718): Use the "posted message task source".
         let _ = self.script_chan.send(CommonScriptMsg::Task(
             ScriptThreadEventCategory::DomEvent,
-            box self.task_canceller().wrap_task(task),
+            Box::new(self.task_canceller().wrap_task(task)),
         ));
     }
 }
diff --git a/servo/components/script/dom/windowproxy.rs b/servo/components/script/dom/windowproxy.rs
index 3d5faba1ad33..663b6fd7030c 100644
--- a/servo/components/script/dom/windowproxy.rs
+++ b/servo/components/script/dom/windowproxy.rs
@@ -115,11 +115,13 @@ impl WindowProxy {
 
             // Create a new browsing context.
             let current = Some(window.global().pipeline_id());
-            let mut window_proxy = box WindowProxy::new_inherited(browsing_context_id,
-                                                                  top_level_browsing_context_id,
-                                                                  current,
-                                                                  frame_element,
-                                                                  parent);
+            let mut window_proxy = Box::new(WindowProxy::new_inherited(
+                browsing_context_id,
+                top_level_browsing_context_id,
+                current,
+                frame_element,
+                parent
+            ));
 
             // The window proxy owns the browsing context.
             // When we finalize the window proxy, it drops the browsing context it owns.
@@ -149,11 +151,13 @@ impl WindowProxy {
             let cx = global_to_clone_from.get_cx();
 
             // Create a new browsing context.
-            let mut window_proxy = box WindowProxy::new_inherited(browsing_context_id,
-                                                                  top_level_browsing_context_id,
-                                                                  None,
-                                                                  None,
-                                                                  parent);
+            let mut window_proxy = Box::new(WindowProxy::new_inherited(
+                browsing_context_id,
+                top_level_browsing_context_id,
+                None,
+                None,
+                parent
+            ));
 
             // Create a new dissimilar-origin window.
             let window = DissimilarOriginWindow::new(global_to_clone_from, &*window_proxy);
diff --git a/servo/components/script/dom/worker.rs b/servo/components/script/dom/worker.rs
index d437b19c1489..4963b57c3aaa 100644
--- a/servo/components/script/dom/worker.rs
+++ b/servo/components/script/dom/worker.rs
@@ -61,7 +61,7 @@ impl Worker {
     pub fn new(global: &GlobalScope,
                sender: Sender<(TrustedWorkerAddress, WorkerScriptMsg)>,
                closing: Arc<AtomicBool>) -> DomRoot<Worker> {
-        reflect_dom_object(box Worker::new_inherited(sender, closing),
+        reflect_dom_object(Box::new(Worker::new_inherited(sender, closing)),
                            global,
                            WorkerBinding::Wrap)
     }
diff --git a/servo/components/script/dom/workerlocation.rs b/servo/components/script/dom/workerlocation.rs
index ca7d30d4d3cb..0a20874c5776 100644
--- a/servo/components/script/dom/workerlocation.rs
+++ b/servo/components/script/dom/workerlocation.rs
@@ -28,7 +28,7 @@ impl WorkerLocation {
     }
 
     pub fn new(global: &WorkerGlobalScope, url: ServoUrl) -> DomRoot<WorkerLocation> {
-        reflect_dom_object(box WorkerLocation::new_inherited(url),
+        reflect_dom_object(Box::new(WorkerLocation::new_inherited(url)),
                            global,
                            WorkerLocationBinding::Wrap)
     }
diff --git a/servo/components/script/dom/workernavigator.rs b/servo/components/script/dom/workernavigator.rs
index e11347c34c64..47c48df9226a 100644
--- a/servo/components/script/dom/workernavigator.rs
+++ b/servo/components/script/dom/workernavigator.rs
@@ -28,7 +28,7 @@ impl WorkerNavigator {
     }
 
     pub fn new(global: &WorkerGlobalScope) -> DomRoot<WorkerNavigator> {
-        reflect_dom_object(box WorkerNavigator::new_inherited(),
+        reflect_dom_object(Box::new(WorkerNavigator::new_inherited()),
                            global,
                            WorkerNavigatorBinding::Wrap)
     }
diff --git a/servo/components/script/dom/worklet.rs b/servo/components/script/dom/worklet.rs
index 5b822ab9d4f7..80cf89772dda 100644
--- a/servo/components/script/dom/worklet.rs
+++ b/servo/components/script/dom/worklet.rs
@@ -94,7 +94,7 @@ impl Worklet {
 
     pub fn new(window: &Window, global_type: WorkletGlobalScopeType) -> DomRoot<Worklet> {
         debug!("Creating worklet {:?}.", global_type);
-        reflect_dom_object(box Worklet::new_inherited(window, global_type), window, Wrap)
+        reflect_dom_object(Box::new(Worklet::new_inherited(window, global_type)), window, Wrap)
     }
 
     pub fn worklet_id(&self) -> WorkletId {
@@ -646,7 +646,7 @@ impl WorkletThread {
     where
         T: TaskBox + 'static,
     {
-        let msg = CommonScriptMsg::Task(ScriptThreadEventCategory::WorkletEvent, box task);
+        let msg = CommonScriptMsg::Task(ScriptThreadEventCategory::WorkletEvent, Box::new(task));
         let msg = MainThreadScriptMsg::Common(msg);
         self.global_init.to_script_thread_sender.send(msg).expect("Worklet thread outlived script thread.");
     }
diff --git a/servo/components/script/dom/xmldocument.rs b/servo/components/script/dom/xmldocument.rs
index f5ef640abce9..acbdea33582a 100644
--- a/servo/components/script/dom/xmldocument.rs
+++ b/servo/components/script/dom/xmldocument.rs
@@ -2,11 +2,11 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use core::nonzero::NonZero;
 use document_loader::DocumentLoader;
 use dom::bindings::codegen::Bindings::DocumentBinding::DocumentMethods;
 use dom::bindings::codegen::Bindings::XMLDocumentBinding::{self, XMLDocumentMethods};
 use dom::bindings::inheritance::Castable;
+use dom::bindings::nonnull::NonNullJSObjectPtr;
 use dom::bindings::reflector::reflect_dom_object;
 use dom::bindings::root::DomRoot;
 use dom::bindings::str::DOMString;
@@ -15,7 +15,7 @@ use dom::location::Location;
 use dom::node::Node;
 use dom::window::Window;
 use dom_struct::dom_struct;
-use js::jsapi::{JSContext, JSObject};
+use js::jsapi::JSContext;
 use script_traits::DocumentActivity;
 use servo_url::{MutableOrigin, ServoUrl};
 
@@ -64,18 +64,21 @@ impl XMLDocument {
                doc_loader: DocumentLoader)
                -> DomRoot<XMLDocument> {
         let doc = reflect_dom_object(
-            box XMLDocument::new_inherited(window,
-                                           has_browsing_context,
-                                           url,
-                                           origin,
-                                           doctype,
-                                           content_type,
-                                           last_modified,
-                                           activity,
-                                           source,
-                                           doc_loader),
+            Box::new(XMLDocument::new_inherited(
+                window,
+                has_browsing_context,
+                url,
+                origin,
+                doctype,
+                content_type,
+                last_modified,
+                activity,
+                source,
+                doc_loader
+            )),
             window,
-            XMLDocumentBinding::Wrap);
+            XMLDocumentBinding::Wrap
+        );
         {
             let node = doc.upcast::<Node>();
             node.set_owner_doc(&doc.document);
@@ -97,7 +100,7 @@ impl XMLDocumentMethods for XMLDocument {
 
     #[allow(unsafe_code)]
     // https://html.spec.whatwg.org/multipage/#dom-tree-accessors:dom-document-nameditem-filter
-    unsafe fn NamedGetter(&self, _cx: *mut JSContext, name: DOMString) -> Option<NonZero<*mut JSObject>> {
+    unsafe fn NamedGetter(&self, _cx: *mut JSContext, name: DOMString) -> Option<NonNullJSObjectPtr> {
         self.upcast::<Document>().NamedGetter(_cx, name)
     }
 }
diff --git a/servo/components/script/dom/xmlhttprequest.rs b/servo/components/script/dom/xmlhttprequest.rs
index 4b9b2b45a4c7..2baa73510342 100644
--- a/servo/components/script/dom/xmlhttprequest.rs
+++ b/servo/components/script/dom/xmlhttprequest.rs
@@ -204,7 +204,7 @@ impl XMLHttpRequest {
         }
     }
     pub fn new(global: &GlobalScope) -> DomRoot<XMLHttpRequest> {
-        reflect_dom_object(box XMLHttpRequest::new_inherited(global),
+        reflect_dom_object(Box::new(XMLHttpRequest::new_inherited(global)),
                            global,
                            XMLHttpRequestBinding::Wrap)
     }
@@ -263,9 +263,9 @@ impl XMLHttpRequest {
             task_source: task_source,
             canceller: Some(global.task_canceller())
         };
-        ROUTER.add_route(action_receiver.to_opaque(), box move |message| {
+        ROUTER.add_route(action_receiver.to_opaque(), Box::new(move |message| {
             listener.notify_fetch(message.to().unwrap());
-        });
+        }));
         global.core_resource_thread().send(Fetch(init, action_sender)).unwrap();
     }
 }
diff --git a/servo/components/script/dom/xmlhttprequestupload.rs b/servo/components/script/dom/xmlhttprequestupload.rs
index 7c6a1a4f5131..83a7f1d0e775 100644
--- a/servo/components/script/dom/xmlhttprequestupload.rs
+++ b/servo/components/script/dom/xmlhttprequestupload.rs
@@ -21,7 +21,7 @@ impl XMLHttpRequestUpload {
         }
     }
     pub fn new(global: &GlobalScope) -> DomRoot<XMLHttpRequestUpload> {
-        reflect_dom_object(box XMLHttpRequestUpload::new_inherited(),
+        reflect_dom_object(Box::new(XMLHttpRequestUpload::new_inherited()),
                            global,
                            XMLHttpRequestUploadBinding::Wrap)
     }
diff --git a/servo/components/script/fetch.rs b/servo/components/script/fetch.rs
index 7a6f63f7b406..edfe9040c419 100644
--- a/servo/components/script/fetch.rs
+++ b/servo/components/script/fetch.rs
@@ -105,9 +105,9 @@ pub fn Fetch(global: &GlobalScope, input: RequestInfo, init: RootedTraceableBox<
         canceller: Some(global.task_canceller())
     };
 
-    ROUTER.add_route(action_receiver.to_opaque(), box move |message| {
+    ROUTER.add_route(action_receiver.to_opaque(), Box::new(move |message| {
         listener.notify_fetch(message.to().unwrap());
-    });
+    }));
     core_resource_thread.send(NetTraitsFetch(request_init, action_sender)).unwrap();
 
     promise
diff --git a/servo/components/script/layout_image.rs b/servo/components/script/layout_image.rs
index 83f4510cf846..4877be1907e8 100644
--- a/servo/components/script/layout_image.rs
+++ b/servo/components/script/layout_image.rs
@@ -64,9 +64,9 @@ pub fn fetch_image_for_layout(url: ServoUrl,
         task_source: window.networking_task_source(),
         canceller: Some(window.task_canceller()),
     };
-    ROUTER.add_route(action_receiver.to_opaque(), box move |message| {
+    ROUTER.add_route(action_receiver.to_opaque(), Box::new(move |message| {
         listener.notify_fetch(message.to().unwrap());
-    });
+    }));
 
     let request = FetchRequestInit {
         url: url,
diff --git a/servo/components/script/lib.rs b/servo/components/script/lib.rs
index cf7f26db0948..5f33f1e11510 100644
--- a/servo/components/script/lib.rs
+++ b/servo/components/script/lib.rs
@@ -2,15 +2,11 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#![feature(box_syntax)]
+#![cfg_attr(feature = "unstable", feature(core_intrinsics))]
+#![cfg_attr(feature = "unstable", feature(on_unimplemented))]
 #![feature(conservative_impl_trait)]
 #![feature(const_fn)]
-#![feature(const_ptr_null)]
-#![feature(const_ptr_null_mut)]
-#![feature(core_intrinsics)]
 #![feature(mpsc_select)]
-#![feature(nonzero)]
-#![feature(on_unimplemented)]
 #![feature(plugin)]
 #![feature(proc_macro)]
 
@@ -32,7 +28,6 @@ extern crate byteorder;
 extern crate canvas_traits;
 extern crate caseless;
 extern crate cookie as cookie_rs;
-extern crate core;
 #[macro_use] extern crate cssparser;
 #[macro_use] extern crate deny_public_fields;
 extern crate devtools_traits;
@@ -68,6 +63,7 @@ extern crate mime_guess;
 extern crate mitochondria;
 extern crate msg;
 extern crate net_traits;
+extern crate nonzero;
 extern crate num_traits;
 extern crate offscreen_gl_context;
 extern crate open;
diff --git a/servo/components/script/script_thread.rs b/servo/components/script/script_thread.rs
index 244038e08f34..6c722cec865a 100644
--- a/servo/components/script/script_thread.rs
+++ b/servo/components/script/script_thread.rs
@@ -124,6 +124,7 @@ use time::{get_time, precise_time_ns, Tm};
 use url::Position;
 use url::percent_encoding::percent_decode;
 use webdriver_handlers;
+use webrender_api::DocumentId;
 use webvr_traits::{WebVREvent, WebVRMsg};
 
 pub type ImageCacheMsg = (PipelineId, PendingImageResponse);
@@ -290,7 +291,7 @@ impl ScriptChan for SendableMainThreadScriptChan {
     }
 
     fn clone(&self) -> Box<ScriptChan + Send> {
-        box SendableMainThreadScriptChan((&self.0).clone())
+        Box::new(SendableMainThreadScriptChan((&self.0).clone()))
     }
 }
 
@@ -304,7 +305,7 @@ impl ScriptChan for MainThreadScriptChan {
     }
 
     fn clone(&self) -> Box<ScriptChan + Send> {
-        box MainThreadScriptChan((&self.0).clone())
+        Box::new(MainThreadScriptChan((&self.0).clone()))
     }
 }
 
@@ -495,6 +496,9 @@ pub struct ScriptThread {
 
     /// https://html.spec.whatwg.org/multipage/#custom-element-reactions-stack
     custom_element_reaction_stack: CustomElementReactionStack,
+
+    /// The Webrender Document ID associated with this thread.
+    webrender_document: DocumentId,
 }
 
 /// In the event of thread panic, all data on the stack runs its destructor. However, there
@@ -804,7 +808,7 @@ impl ScriptThread {
         // Ask the router to proxy IPC messages from the control port to us.
         let control_port = ROUTER.route_ipc_receiver_to_new_mpsc_receiver(state.control_port);
 
-        let boxed_script_sender = box MainThreadScriptChan(chan.clone());
+        let boxed_script_sender = Box::new(MainThreadScriptChan(chan.clone()));
 
         let (image_cache_channel, image_cache_port) = channel();
 
@@ -871,6 +875,8 @@ impl ScriptThread {
             transitioning_nodes: Default::default(),
 
             custom_element_reaction_stack: CustomElementReactionStack::new(),
+
+            webrender_document: state.webrender_document,
         }
     }
 
@@ -2062,6 +2068,7 @@ impl ScriptThread {
             self.webgl_chan.channel(),
             self.webvr_chan.clone(),
             self.microtask_queue.clone(),
+            self.webrender_document,
         );
 
         // Initialize the browsing context for the window.
diff --git a/servo/components/script/stylesheet_loader.rs b/servo/components/script/stylesheet_loader.rs
index e789d32e7b04..3444cb0af020 100644
--- a/servo/components/script/stylesheet_loader.rs
+++ b/servo/components/script/stylesheet_loader.rs
@@ -231,9 +231,9 @@ impl<'a> StylesheetLoader<'a> {
             task_source: document.window().networking_task_source(),
             canceller: Some(document.window().task_canceller())
         };
-        ROUTER.add_route(action_receiver.to_opaque(), box move |message| {
+        ROUTER.add_route(action_receiver.to_opaque(), Box::new(move |message| {
             listener.notify_fetch(message.to().unwrap());
-        });
+        }));
 
 
         let owner = self.elem.upcast::<Element>().as_stylesheet_owner()
diff --git a/servo/components/script/task.rs b/servo/components/script/task.rs
index e90fc21c55cd..eab786c8c20d 100644
--- a/servo/components/script/task.rs
+++ b/servo/components/script/task.rs
@@ -5,7 +5,6 @@
 //! Machinery for [tasks](https://html.spec.whatwg.org/multipage/#concept-task).
 
 use std::fmt;
-use std::intrinsics;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, Ordering};
 
@@ -33,7 +32,10 @@ macro_rules! task {
 pub trait TaskOnce: Send {
     #[allow(unsafe_code)]
     fn name(&self) -> &'static str {
-        unsafe { intrinsics::type_name::<Self>() }
+        #[cfg(feature = "unstable")]
+        unsafe { ::std::intrinsics::type_name::<Self>() }
+        #[cfg(not(feature = "unstable"))]
+        { "(task name unknown)" }
     }
 
     fn run_once(self);
diff --git a/servo/components/script/task_source/dom_manipulation.rs b/servo/components/script/task_source/dom_manipulation.rs
index 30dd3df88518..5eb20d2d274f 100644
--- a/servo/components/script/task_source/dom_manipulation.rs
+++ b/servo/components/script/task_source/dom_manipulation.rs
@@ -36,7 +36,7 @@ impl TaskSource for DOMManipulationTaskSource {
     {
         let msg = MainThreadScriptMsg::Common(CommonScriptMsg::Task(
             ScriptThreadEventCategory::ScriptEvent,
-            box canceller.wrap_task(task),
+            Box::new(canceller.wrap_task(task)),
         ));
         self.0.send(msg).map_err(|_| ())
     }
diff --git a/servo/components/script/task_source/file_reading.rs b/servo/components/script/task_source/file_reading.rs
index fc9af75794c5..fe2ae2e4d179 100644
--- a/servo/components/script/task_source/file_reading.rs
+++ b/servo/components/script/task_source/file_reading.rs
@@ -29,7 +29,7 @@ impl TaskSource for FileReadingTaskSource {
     {
         self.0.send(CommonScriptMsg::Task(
             ScriptThreadEventCategory::FileRead,
-            box canceller.wrap_task(task),
+            Box::new(canceller.wrap_task(task)),
         ))
     }
 }
diff --git a/servo/components/script/task_source/history_traversal.rs b/servo/components/script/task_source/history_traversal.rs
index e5887264cf64..ffd657adada5 100644
--- a/servo/components/script/task_source/history_traversal.rs
+++ b/servo/components/script/task_source/history_traversal.rs
@@ -15,6 +15,6 @@ impl ScriptChan for HistoryTraversalTaskSource {
     }
 
     fn clone(&self) -> Box<ScriptChan + Send> {
-        box HistoryTraversalTaskSource((&self.0).clone())
+        Box::new(HistoryTraversalTaskSource((&self.0).clone()))
     }
 }
diff --git a/servo/components/script/task_source/networking.rs b/servo/components/script/task_source/networking.rs
index 8b167c5d9053..41795227e5d4 100644
--- a/servo/components/script/task_source/networking.rs
+++ b/servo/components/script/task_source/networking.rs
@@ -26,7 +26,7 @@ impl TaskSource for NetworkingTaskSource {
     {
         self.0.send(CommonScriptMsg::Task(
             ScriptThreadEventCategory::NetworkEvent,
-            box canceller.wrap_task(task),
+            Box::new(canceller.wrap_task(task)),
         ))
     }
 }
@@ -40,7 +40,7 @@ impl NetworkingTaskSource {
     {
         self.0.send(CommonScriptMsg::Task(
             ScriptThreadEventCategory::NetworkEvent,
-            box task,
+            Box::new(task),
         ))
     }
 }
diff --git a/servo/components/script/task_source/performance_timeline.rs b/servo/components/script/task_source/performance_timeline.rs
index 1a3ffeb7fc72..0de171c4949c 100644
--- a/servo/components/script/task_source/performance_timeline.rs
+++ b/servo/components/script/task_source/performance_timeline.rs
@@ -40,7 +40,7 @@ impl TaskSource for PerformanceTimelineTaskSource {
     {
         let msg = CommonScriptMsg::Task(
             ScriptThreadEventCategory::PerformanceTimelineTask,
-            box canceller.wrap_task(task)
+            Box::new(canceller.wrap_task(task))
         );
         self.0.send(msg).map_err(|_| ())
     }
diff --git a/servo/components/script/task_source/user_interaction.rs b/servo/components/script/task_source/user_interaction.rs
index 9891f4745296..c10e870ac7e7 100644
--- a/servo/components/script/task_source/user_interaction.rs
+++ b/servo/components/script/task_source/user_interaction.rs
@@ -36,7 +36,7 @@ impl TaskSource for UserInteractionTaskSource {
     {
         let msg = MainThreadScriptMsg::Common(CommonScriptMsg::Task(
             ScriptThreadEventCategory::InputEvent,
-            box canceller.wrap_task(task),
+            Box::new(canceller.wrap_task(task)),
         ));
         self.0.send(msg).map_err(|_| ())
     }
diff --git a/servo/components/script_layout_interface/Cargo.toml b/servo/components/script_layout_interface/Cargo.toml
index 9dfad06a89cf..47e47222c7d2 100644
--- a/servo/components/script_layout_interface/Cargo.toml
+++ b/servo/components/script_layout_interface/Cargo.toml
@@ -19,7 +19,7 @@ gfx_traits = {path = "../gfx_traits"}
 heapsize = "0.4"
 heapsize_derive = "0.1"
 html5ever = "0.20.0"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 libc = "0.2"
 log = "0.3.5"
 metrics = {path = "../metrics"}
diff --git a/servo/components/script_layout_interface/lib.rs b/servo/components/script_layout_interface/lib.rs
index 7b45d9688f19..0216ca845436 100644
--- a/servo/components/script_layout_interface/lib.rs
+++ b/servo/components/script_layout_interface/lib.rs
@@ -45,10 +45,9 @@ use canvas_traits::canvas::CanvasMsg;
 use ipc_channel::ipc::IpcSender;
 use libc::c_void;
 use net_traits::image_cache::PendingImageId;
-use nonzero::NonZeroUsize;
+use nonzero::NonZero;
 use script_traits::UntrustedNodeAddress;
 use servo_url::ServoUrl;
-use std::marker::PhantomData;
 use std::sync::atomic::AtomicIsize;
 use style::data::ElementData;
 
@@ -78,8 +77,7 @@ pub struct OpaqueStyleAndLayoutData {
     // NB: We really store a `StyleAndLayoutData` here, so be careful!
     #[ignore_heap_size_of = "TODO(#6910) Box value that should be counted but \
                              the type lives in layout"]
-    pub ptr: NonZeroUsize,
-    pub phantom: PhantomData<*mut StyleData>,
+    pub ptr: NonZero<*mut StyleData>,
 }
 
 #[allow(unsafe_code)]
diff --git a/servo/components/script_traits/Cargo.toml b/servo/components/script_traits/Cargo.toml
index 3e957cf29aed..88fb50c33848 100644
--- a/servo/components/script_traits/Cargo.toml
+++ b/servo/components/script_traits/Cargo.toml
@@ -20,7 +20,7 @@ heapsize = "0.4"
 heapsize_derive = "0.1"
 hyper = "0.10"
 hyper_serde = "0.7"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 libc = "0.2"
 msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
diff --git a/servo/components/script_traits/lib.rs b/servo/components/script_traits/lib.rs
index 8b2c98b1eb62..e8081c9eeafa 100644
--- a/servo/components/script_traits/lib.rs
+++ b/servo/components/script_traits/lib.rs
@@ -69,7 +69,7 @@ use std::sync::mpsc::{Receiver, Sender, RecvTimeoutError};
 use style_traits::CSSPixel;
 use style_traits::SpeculativePainter;
 use webdriver_msg::{LoadStatus, WebDriverScriptCommand};
-use webrender_api::{ClipId, DevicePixel, ImageKey};
+use webrender_api::{ClipId, DevicePixel, DocumentId, ImageKey};
 use webvr_traits::{WebVREvent, WebVRMsg};
 
 pub use script_msg::{LayoutMsg, ScriptMsg, EventResult, LogEntry};
@@ -554,7 +554,9 @@ pub struct InitialScriptState {
     /// A channel to the webgl thread used in this pipeline.
     pub webgl_chan: WebGLPipeline,
     /// A channel to the webvr thread, if available.
-    pub webvr_chan: Option<IpcSender<WebVRMsg>>
+    pub webvr_chan: Option<IpcSender<WebVRMsg>>,
+    /// The Webrender document ID associated with this thread.
+    pub webrender_document: DocumentId,
 }
 
 /// This trait allows creating a `ScriptThread` without depending on the `script`
diff --git a/servo/components/selectors/matching.rs b/servo/components/selectors/matching.rs
index 711bec885d46..596fa8afe9f6 100644
--- a/servo/components/selectors/matching.rs
+++ b/servo/components/selectors/matching.rs
@@ -299,11 +299,10 @@ where
 /// Whether a compound selector matched, and whether it was the rightmost
 /// selector inside the complex selector.
 pub enum CompoundSelectorMatchingResult {
+    /// The selector was fully matched.
+    FullyMatched,
     /// The compound selector matched, and the next combinator offset is
     /// `next_combinator_offset`.
-    ///
-    /// If the next combinator offset is zero, it means that it's the rightmost
-    /// selector.
     Matched { next_combinator_offset: usize, },
     /// The selector didn't match.
     NotMatched,
@@ -325,8 +324,9 @@ pub fn matches_compound_selector<E>(
 where
     E: Element
 {
+    debug_assert_ne!(from_offset, 0);
     if cfg!(debug_assertions) {
-        selector.combinator_at(from_offset); // This asserts.
+        selector.combinator_at_parse_order(from_offset - 1); // This asserts.
     }
 
     let mut local_context = LocalMatchingContext {
@@ -334,10 +334,11 @@ where
         matches_hover_and_active_quirk: false,
     };
 
-    for component in selector.iter_raw_parse_order_from(from_offset - 1) {
+    for component in selector.iter_raw_parse_order_from(from_offset) {
         if matches!(*component, Component::Combinator(..)) {
+            debug_assert_ne!(from_offset, 0, "Selector started with a combinator?");
             return CompoundSelectorMatchingResult::Matched {
-                next_combinator_offset: from_offset - 1,
+                next_combinator_offset: from_offset,
             }
         }
 
@@ -350,12 +351,10 @@ where
             return CompoundSelectorMatchingResult::NotMatched;
         }
 
-        from_offset -= 1;
+        from_offset += 1;
     }
 
-    return CompoundSelectorMatchingResult::Matched {
-        next_combinator_offset: 0,
-    }
+    CompoundSelectorMatchingResult::FullyMatched
 }
 
 /// Matches a complex selector.
diff --git a/servo/components/selectors/parser.rs b/servo/components/selectors/parser.rs
index 6b87ed96720a..093ccf366e17 100644
--- a/servo/components/selectors/parser.rs
+++ b/servo/components/selectors/parser.rs
@@ -440,12 +440,11 @@ impl<Impl: SelectorImpl> Selector<Impl> {
         }
     }
 
-    /// Returns the combinator at index `index` (one-indexed from the right),
+    /// Returns the combinator at index `index` (zero-indexed from the right),
     /// or panics if the component is not a combinator.
-    ///
-    /// FIXME(bholley): Use more intuitive indexing.
-    pub fn combinator_at(&self, index: usize) -> Combinator {
-        match self.0.slice[index - 1] {
+    #[inline]
+    pub fn combinator_at_match_order(&self, index: usize) -> Combinator {
+        match self.0.slice[index] {
             Component::Combinator(c) => c,
             ref other => {
                 panic!("Not a combinator: {:?}, {:?}, index: {}",
@@ -460,16 +459,24 @@ impl<Impl: SelectorImpl> Selector<Impl> {
         self.0.slice.iter()
     }
 
+    /// Returns the combinator at index `index` (zero-indexed from the left),
+    /// or panics if the component is not a combinator.
+    #[inline]
+    pub fn combinator_at_parse_order(&self, index: usize) -> Combinator {
+        match self.0.slice[self.len() - index - 1] {
+            Component::Combinator(c) => c,
+            ref other => {
+                panic!("Not a combinator: {:?}, {:?}, index: {}",
+                       other, self, index)
+            }
+        }
+    }
+
     /// Returns an iterator over the sequence of simple selectors and
-    /// combinators, in parse order (from left to right), _starting_
-    /// 'offset_from_right' entries from the past-the-end sentinel on
-    /// the right. So "0" panics,. "1" iterates nothing, and "len"
-    /// iterates the entire sequence.
-    ///
-    /// FIXME(bholley): This API is rather unintuive, and should really
-    /// be changed to accept an offset from the left. Same for combinator_at.
-    pub fn iter_raw_parse_order_from(&self, offset_from_right: usize) -> Rev<slice::Iter<Component<Impl>>> {
-        self.0.slice[..offset_from_right].iter().rev()
+    /// combinators, in parse order (from left to right), starting from
+    /// `offset`.
+    pub fn iter_raw_parse_order_from(&self, offset: usize) -> Rev<slice::Iter<Component<Impl>>> {
+        self.0.slice[..self.len() - offset].iter().rev()
     }
 
     /// Creates a Selector from a vec of Components, specified in parse order. Used in tests.
diff --git a/servo/components/servo/Cargo.toml b/servo/components/servo/Cargo.toml
index 3f7f3c825983..9149a2918b1f 100644
--- a/servo/components/servo/Cargo.toml
+++ b/servo/components/servo/Cargo.toml
@@ -23,6 +23,7 @@ unstable = [
     "gfx/unstable",
     "msg/unstable",
     "profile/unstable",
+    "script/unstable",
 ]
 
 [dependencies]
@@ -39,7 +40,7 @@ env_logger = "0.4"
 euclid = "0.15"
 gfx = {path = "../gfx"}
 gleam = "0.4"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 layout_thread = {path = "../layout_thread"}
 log = "0.3"
 msg = {path = "../msg"}
diff --git a/servo/components/servo/lib.rs b/servo/components/servo/lib.rs
index 262f5a221302..d5462459e9ad 100644
--- a/servo/components/servo/lib.rs
+++ b/servo/components/servo/lib.rs
@@ -183,7 +183,7 @@ impl<Window> Servo<Window> where Window: WindowMethods + 'static {
             };
 
             let mut debug_flags = webrender::DebugFlags::empty();
-            debug_flags.set(webrender::PROFILER_DBG, opts.webrender_stats);
+            debug_flags.set(webrender::DebugFlags::PROFILER_DBG, opts.webrender_stats);
 
             webrender::Renderer::new(window.gl(), webrender::RendererOptions {
                 device_pixel_ratio: device_pixel_ratio,
@@ -553,13 +553,18 @@ fn create_constellation(user_agent: Cow<'static, str>,
     };
 
     // Initialize WebGL Thread entry point.
-    let (webgl_threads, image_handler) = WebGLThreads::new(gl_factory,
-                                                           window_gl,
-                                                           webrender_api_sender.clone(),
-                                                           webvr_compositor.map(|c| c as Box<_>));
+    let (webgl_threads, image_handler, output_handler) = WebGLThreads::new(gl_factory,
+                                                                           window_gl,
+                                                                           webrender_api_sender.clone(),
+                                                                           webvr_compositor.map(|c| c as Box<_>));
     // Set webrender external image handler for WebGL textures
     webrender.set_external_image_handler(image_handler);
 
+    // Set DOM to texture handler, if enabled.
+    if let Some(output_handler) = output_handler {
+        webrender.set_output_image_handler(output_handler);
+    }
+
     let initial_state = InitialConstellationState {
         compositor_proxy,
         embedder_proxy,
diff --git a/servo/components/style/Cargo.toml b/servo/components/style/Cargo.toml
index 1e61fbc22993..140c1b7d0945 100644
--- a/servo/components/style/Cargo.toml
+++ b/servo/components/style/Cargo.toml
@@ -60,7 +60,6 @@ num-traits = "0.1.32"
 ordered-float = "0.4"
 owning_ref = "0.3.3"
 parking_lot = "0.4"
-pdqsort = "0.1.0"
 precomputed-hash = "0.1.1"
 rayon = "0.8.2"
 selectors = { path = "../selectors" }
diff --git a/servo/components/style/dom.rs b/servo/components/style/dom.rs
index ed8b52f02efa..1733b580184f 100644
--- a/servo/components/style/dom.rs
+++ b/servo/components/style/dom.rs
@@ -20,8 +20,8 @@ use properties::{AnimationRules, ComputedValues, PropertyDeclarationBlock};
 #[cfg(feature = "gecko")] use properties::LonghandId;
 #[cfg(feature = "gecko")] use properties::animated_properties::AnimationValue;
 use rule_tree::CascadeLevel;
-use selector_parser::{AttrValue, ElementExt};
-use selector_parser::{PseudoClassStringArg, PseudoElement};
+use selector_parser::{AttrValue, PseudoClassStringArg, PseudoElement, SelectorImpl};
+use selectors::Element as SelectorsElement;
 use selectors::matching::{ElementSelectorFlags, VisitedHandlingMode};
 use selectors::sink::Push;
 use servo_arc::{Arc, ArcBorrow};
@@ -242,8 +242,17 @@ pub trait PresentationalHintsSynthesizer {
 }
 
 /// The element trait, the main abstraction the style crate acts over.
-pub trait TElement : Eq + PartialEq + Debug + Hash + Sized + Copy + Clone +
-                     ElementExt + PresentationalHintsSynthesizer {
+pub trait TElement
+    : Eq
+    + PartialEq
+    + Debug
+    + Hash
+    + Sized
+    + Copy
+    + Clone
+    + SelectorsElement<Impl = SelectorImpl>
+    + PresentationalHintsSynthesizer
+{
     /// The concrete node type.
     type ConcreteNode: TNode<ConcreteElement = Self>;
 
@@ -263,6 +272,11 @@ pub trait TElement : Eq + PartialEq + Debug + Hash + Sized + Copy + Clone +
     /// font-size used for rem units.
     fn owner_doc_matches_for_testing(&self, _: &Device) -> bool { true }
 
+    /// Whether this element should match user and author rules.
+    ///
+    /// We use this for Native Anonymous Content in Gecko.
+    fn matches_user_and_author_rules(&self) -> bool { true }
+
     /// Returns the depth of this element in the DOM.
     fn depth(&self) -> usize {
         let mut depth = 0;
diff --git a/servo/components/style/gecko/wrapper.rs b/servo/components/style/gecko/wrapper.rs
index 052fb627f9e2..e259422c6298 100644
--- a/servo/components/style/gecko/wrapper.rs
+++ b/servo/components/style/gecko/wrapper.rs
@@ -75,7 +75,7 @@ use properties::animated_properties::{AnimationValue, AnimationValueMap};
 use properties::animated_properties::TransitionProperty;
 use properties::style_structs::Font;
 use rule_tree::CascadeLevel as ServoCascadeLevel;
-use selector_parser::{AttrValue, ElementExt, PseudoClassStringArg};
+use selector_parser::{AttrValue, PseudoClassStringArg};
 use selectors::{Element, OpaqueElement};
 use selectors::attr::{AttrSelectorOperation, AttrSelectorOperator, CaseSensitivity, NamespaceConstraint};
 use selectors::matching::{ElementSelectorFlags, MatchingContext};
@@ -1105,6 +1105,11 @@ impl<'le> TElement for GeckoElement<'le> {
         self.flags() & (NODE_IS_NATIVE_ANONYMOUS as u32) != 0
     }
 
+    #[inline]
+    fn matches_user_and_author_rules(&self) -> bool {
+        !self.is_in_native_anonymous_subtree()
+    }
+
     fn implemented_pseudo_element(&self) -> Option<PseudoElement> {
         if !self.is_native_anonymous() {
             return None;
@@ -2069,10 +2074,3 @@ impl<'a> NamespaceConstraintHelpers for NamespaceConstraint<&'a Namespace> {
         }
     }
 }
-
-impl<'le> ElementExt for GeckoElement<'le> {
-    #[inline]
-    fn matches_user_and_author_rules(&self) -> bool {
-        !self.is_in_native_anonymous_subtree()
-    }
-}
diff --git a/servo/components/style/invalidation/element/collector.rs b/servo/components/style/invalidation/element/collector.rs
index 82d99c025dcc..b1971bfab196 100644
--- a/servo/components/style/invalidation/element/collector.rs
+++ b/servo/components/style/invalidation/element/collector.rs
@@ -463,16 +463,18 @@ where
 
         if dependency.affects_descendants() {
             debug_assert_ne!(dependency.selector_offset, 0);
+            debug_assert_ne!(dependency.selector_offset, dependency.selector.len());
             debug_assert!(!dependency.affects_later_siblings());
             self.descendant_invalidations.push(Invalidation::new(
                 dependency.selector.clone(),
-                dependency.selector_offset,
+                dependency.selector.len() - dependency.selector_offset + 1,
             ));
         } else if dependency.affects_later_siblings() {
             debug_assert_ne!(dependency.selector_offset, 0);
+            debug_assert_ne!(dependency.selector_offset, dependency.selector.len());
             self.sibling_invalidations.push(Invalidation::new(
                 dependency.selector.clone(),
-                dependency.selector_offset,
+                dependency.selector.len() - dependency.selector_offset + 1,
             ));
         }
     }
diff --git a/servo/components/style/invalidation/element/invalidation_map.rs b/servo/components/style/invalidation/element/invalidation_map.rs
index 2e4816aad348..bcc597330f10 100644
--- a/servo/components/style/invalidation/element/invalidation_map.rs
+++ b/servo/components/style/invalidation/element/invalidation_map.rs
@@ -79,7 +79,7 @@ impl Dependency {
             return None;
         }
 
-        Some(self.selector.combinator_at(self.selector_offset))
+        Some(self.selector.combinator_at_match_order(self.selector_offset - 1))
     }
 
     /// Whether this dependency affects the style of the element.
diff --git a/servo/components/style/invalidation/element/invalidator.rs b/servo/components/style/invalidation/element/invalidator.rs
index 8b269569af93..97edd7a42032 100644
--- a/servo/components/style/invalidation/element/invalidator.rs
+++ b/servo/components/style/invalidation/element/invalidator.rs
@@ -114,14 +114,13 @@ enum InvalidationKind {
 
 /// An `Invalidation` is a complex selector that describes which elements,
 /// relative to a current element we are processing, must be restyled.
-///
-/// When `offset` points to the right-most compound selector in `selector`,
-/// then the Invalidation `represents` the fact that the current element
-/// must be restyled if the compound selector matches.  Otherwise, if
-/// describes which descendants (or later siblings) must be restyled.
 #[derive(Clone)]
 pub struct Invalidation {
     selector: Selector<SelectorImpl>,
+    /// The offset of the selector pointing to a compound selector.
+    ///
+    /// This order is a "parse order" offset, that is, zero is the leftmost part
+    /// of the selector written as parsed / serialized.
     offset: usize,
     /// Whether the invalidation was already matched by any previous sibling or
     /// ancestor.
@@ -149,7 +148,7 @@ impl Invalidation {
         // for the weird pseudos in <input type="number">.
         //
         // We should be able to do better here!
-        match self.selector.combinator_at(self.offset) {
+        match self.selector.combinator_at_parse_order(self.offset - 1) {
             Combinator::NextSibling |
             Combinator::Child => false,
             _ => true,
@@ -157,7 +156,7 @@ impl Invalidation {
     }
 
     fn kind(&self) -> InvalidationKind {
-        if self.selector.combinator_at(self.offset).is_ancestor() {
+        if self.selector.combinator_at_parse_order(self.offset - 1).is_ancestor() {
             InvalidationKind::Descendant
         } else {
             InvalidationKind::Sibling
@@ -170,7 +169,7 @@ impl fmt::Debug for Invalidation {
         use cssparser::ToCss;
 
         f.write_str("Invalidation(")?;
-        for component in self.selector.iter_raw_parse_order_from(self.offset - 1) {
+        for component in self.selector.iter_raw_parse_order_from(self.offset) {
             if matches!(*component, Component::Combinator(..)) {
                 break;
             }
@@ -624,14 +623,14 @@ where
         let mut invalidated_self = false;
         let mut matched = false;
         match matching_result {
-            CompoundSelectorMatchingResult::Matched { next_combinator_offset: 0 } => {
+            CompoundSelectorMatchingResult::FullyMatched => {
                 debug!(" > Invalidation matched completely");
                 matched = true;
                 invalidated_self = true;
             }
             CompoundSelectorMatchingResult::Matched { next_combinator_offset } => {
                 let next_combinator =
-                    invalidation.selector.combinator_at(next_combinator_offset);
+                    invalidation.selector.combinator_at_parse_order(next_combinator_offset);
                 matched = true;
 
                 if matches!(next_combinator, Combinator::PseudoElement) {
@@ -640,7 +639,7 @@ where
                     // around, so there could also be state pseudo-classes.
                     let pseudo_selector =
                         invalidation.selector
-                            .iter_raw_parse_order_from(next_combinator_offset - 1)
+                            .iter_raw_parse_order_from(next_combinator_offset + 1)
                             .skip_while(|c| matches!(**c, Component::NonTSPseudoClass(..)))
                             .next()
                             .unwrap();
@@ -681,7 +680,7 @@ where
 
                 let next_invalidation = Invalidation {
                     selector: invalidation.selector.clone(),
-                    offset: next_combinator_offset,
+                    offset: next_combinator_offset + 1,
                     matched_by_any_previous: false,
                 };
 
diff --git a/servo/components/style/lib.rs b/servo/components/style/lib.rs
index b4b40cf56dba..00a83d1f39ab 100644
--- a/servo/components/style/lib.rs
+++ b/servo/components/style/lib.rs
@@ -73,7 +73,6 @@ extern crate num_traits;
 extern crate ordered_float;
 extern crate owning_ref;
 extern crate parking_lot;
-extern crate pdqsort;
 extern crate precomputed_hash;
 extern crate rayon;
 extern crate selectors;
diff --git a/servo/components/style/matching.rs b/servo/components/style/matching.rs
index 895fbe74320f..3b3ee3e01962 100644
--- a/servo/components/style/matching.rs
+++ b/servo/components/style/matching.rs
@@ -360,8 +360,8 @@ trait PrivateMatchMethods: TElement {
         debug!(" > style difference: {:?}", difference);
 
         // We need to cascade the children in order to ensure the correct
-        // propagation of computed value flags.
-        if old_values.flags != new_values.flags {
+        // propagation of inherited computed value flags.
+        if old_values.flags.inherited() != new_values.flags.inherited() {
             debug!(" > flags changed: {:?} != {:?}", old_values.flags, new_values.flags);
             return ChildCascadeRequirement::MustCascadeChildren;
         }
diff --git a/servo/components/style/properties/computed_value_flags.rs b/servo/components/style/properties/computed_value_flags.rs
index 0e5e5ecd266c..3c1b15474cdf 100644
--- a/servo/components/style/properties/computed_value_flags.rs
+++ b/servo/components/style/properties/computed_value_flags.rs
@@ -64,3 +64,11 @@ bitflags! {
         const IS_STYLE_IF_VISITED = 1 << 9,
     }
 }
+
+impl ComputedValueFlags {
+    /// Returns the flags that are inherited.
+    #[inline]
+    pub fn inherited(self) -> Self {
+        self & !(INHERITS_DISPLAY | INHERITS_CONTENT | INHERITS_RESET_STYLE)
+    }
+}
diff --git a/servo/components/style/properties/properties.mako.rs b/servo/components/style/properties/properties.mako.rs
index b33a91e81df0..df19f4d24dd9 100644
--- a/servo/components/style/properties/properties.mako.rs
+++ b/servo/components/style/properties/properties.mako.rs
@@ -2872,7 +2872,7 @@ impl<'a> StyleBuilder<'a> {
             /* rules = */ None,
             parent.custom_properties().cloned(),
             parent.writing_mode,
-            parent.flags,
+            parent.flags.inherited(),
             visited_style,
         )
     }
diff --git a/servo/components/style/selector_map.rs b/servo/components/style/selector_map.rs
index f44eea6fdddf..9e0f01a2c9f4 100644
--- a/servo/components/style/selector_map.rs
+++ b/servo/components/style/selector_map.rs
@@ -12,7 +12,6 @@ use dom::TElement;
 use fallible::FallibleVec;
 use hash::{HashMap, HashSet, DiagnosticHashMap};
 use hashglobe::FailedAllocationError;
-use pdqsort::sort_by;
 use precomputed_hash::PrecomputedHash;
 use rule_tree::CascadeLevel;
 use selector_parser::SelectorImpl;
@@ -111,11 +110,6 @@ pub struct SelectorMap<T: 'static> {
     pub count: usize,
 }
 
-#[inline]
-fn sort_by_key<T, F: Fn(&T) -> K, K: Ord>(v: &mut [T], f: F) {
-    sort_by(v, |a, b| f(a).cmp(&f(b)))
-}
-
 // FIXME(Manishearth) the 'static bound can be removed when
 // our HashMap fork (hashglobe) is able to use NonZero,
 // or when stdlib gets fallible collections
@@ -227,8 +221,7 @@ impl SelectorMap<Rule> {
                                         cascade_level);
 
         // Sort only the rules we just added.
-        sort_by_key(&mut matching_rules_list[init_len..],
-                    |block| (block.specificity, block.source_order()));
+        matching_rules_list[init_len..].sort_unstable_by_key(|block| (block.specificity, block.source_order()));
     }
 
     /// Adds rules in `rules` that match `element` to the `matching_rules` list.
@@ -523,4 +516,3 @@ impl<V: 'static> MaybeCaseInsensitiveHashMap<Atom, V> {
         self.0.end_mutation();
     }
 }
-
diff --git a/servo/components/style/selector_parser.rs b/servo/components/style/selector_parser.rs
index 316f360daf8e..85b4d09d7586 100644
--- a/servo/components/style/selector_parser.rs
+++ b/servo/components/style/selector_parser.rs
@@ -7,7 +7,6 @@
 #![deny(missing_docs)]
 
 use cssparser::{Parser as CssParser, ParserInput};
-use selectors::Element;
 use selectors::parser::SelectorList;
 use std::fmt::{self, Debug};
 use style_traits::ParseError;
@@ -103,14 +102,6 @@ pub enum PseudoElementCascadeType {
     Precomputed,
 }
 
-/// An extension to rust-selector's `Element` trait.
-pub trait ElementExt: Element<Impl=SelectorImpl> + Debug {
-    /// Whether this element should match user and author rules.
-    ///
-    /// We use this for Native Anonymous Content in Gecko.
-    fn matches_user_and_author_rules(&self) -> bool;
-}
-
 /// A per-functional-pseudo map, from a given pseudo to a `T`.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
diff --git a/servo/components/style/servo/selector_parser.rs b/servo/components/style/servo/selector_parser.rs
index 887503f9a11a..719e76f42f23 100644
--- a/servo/components/style/servo/selector_parser.rs
+++ b/servo/components/style/servo/selector_parser.rs
@@ -16,14 +16,12 @@ use invalidation::element::element_wrapper::ElementSnapshot;
 use properties::ComputedValues;
 use properties::PropertyFlags;
 use properties::longhands::display::computed_value as display;
-use selector_parser::{AttrValue as SelectorAttrValue, ElementExt, PseudoElementCascadeType, SelectorParser};
-use selectors::Element;
+use selector_parser::{AttrValue as SelectorAttrValue, PseudoElementCascadeType, SelectorParser};
 use selectors::attr::{AttrSelectorOperation, NamespaceConstraint, CaseSensitivity};
 use selectors::parser::{SelectorMethods, SelectorParseErrorKind};
 use selectors::visitor::SelectorVisitor;
 use std::ascii::AsciiExt;
 use std::fmt;
-use std::fmt::Debug;
 use std::mem;
 use std::ops::{Deref, DerefMut};
 use style_traits::{ParseError, StyleParseErrorKind};
@@ -715,13 +713,6 @@ impl ServoElementSnapshot {
     }
 }
 
-impl<E: Element<Impl=SelectorImpl> + Debug> ElementExt for E {
-    #[inline]
-    fn matches_user_and_author_rules(&self) -> bool {
-        true
-    }
-}
-
 /// Returns whether the language is matched, as defined by
 /// [RFC 4647](https://tools.ietf.org/html/rfc4647#section-3.3.2).
 pub fn extended_filtering(tag: &str, range: &str) -> bool {
diff --git a/servo/components/style/values/specified/color.rs b/servo/components/style/values/specified/color.rs
index bee0daecfea7..aae2674803ef 100644
--- a/servo/components/style/values/specified/color.rs
+++ b/servo/components/style/values/specified/color.rs
@@ -67,42 +67,7 @@ impl From<RGBA> for Color {
 
 impl Parse for Color {
     fn parse<'i, 't>(_: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
-        // Currently we only store authored value for color keywords,
-        // because all browsers serialize those values as keywords for
-        // specified value.
-        let start = input.state();
-        let authored = match input.next() {
-            Ok(&Token::Ident(ref s)) => Some(s.to_lowercase().into_boxed_str()),
-            _ => None,
-        };
-        input.reset(&start);
-        match input.try(CSSParserColor::parse) {
-            Ok(value) =>
-                Ok(match value {
-                    CSSParserColor::CurrentColor => Color::CurrentColor,
-                    CSSParserColor::RGBA(rgba) => Color::Numeric {
-                        parsed: rgba,
-                        authored: authored,
-                    },
-                }),
-            Err(e) => {
-                #[cfg(feature = "gecko")] {
-                    if let Ok(system) = input.try(SystemColor::parse) {
-                        return Ok(Color::System(system));
-                    } else if let Ok(c) = gecko::SpecialColorKeyword::parse(input) {
-                        return Ok(Color::Special(c));
-                    }
-                }
-                match e {
-                    BasicParseError { kind: BasicParseErrorKind::UnexpectedToken(t), location } => {
-                        Err(location.new_custom_error(
-                            StyleParseErrorKind::ValueError(ValueParseErrorKind::InvalidColor(t))
-                        ))
-                    }
-                    e => Err(e.into())
-                }
-            }
-        }
+        Color::parse_color(input)
     }
 }
 
@@ -244,6 +209,46 @@ impl Color {
             _ => true,
         }
     }
+
+    /// Parse a <color> value.
+    pub fn parse_color<'i, 't>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
+        // Currently we only store authored value for color keywords,
+        // because all browsers serialize those values as keywords for
+        // specified value.
+        let start = input.state();
+        let authored = match input.next() {
+            Ok(&Token::Ident(ref s)) => Some(s.to_lowercase().into_boxed_str()),
+            _ => None,
+        };
+        input.reset(&start);
+        match input.try(CSSParserColor::parse) {
+            Ok(value) =>
+                Ok(match value {
+                    CSSParserColor::CurrentColor => Color::CurrentColor,
+                    CSSParserColor::RGBA(rgba) => Color::Numeric {
+                        parsed: rgba,
+                        authored: authored,
+                    },
+                }),
+            Err(e) => {
+                #[cfg(feature = "gecko")] {
+                    if let Ok(system) = input.try(SystemColor::parse) {
+                        return Ok(Color::System(system));
+                    } else if let Ok(c) = gecko::SpecialColorKeyword::parse(input) {
+                        return Ok(Color::Special(c));
+                    }
+                }
+                match e {
+                    BasicParseError { kind: BasicParseErrorKind::UnexpectedToken(t), location } => {
+                        Err(location.new_custom_error(
+                            StyleParseErrorKind::ValueError(ValueParseErrorKind::InvalidColor(t))
+                        ))
+                    }
+                    e => Err(e.into())
+                }
+            }
+        }
+    }
 }
 
 #[cfg(feature = "gecko")]
@@ -252,53 +257,71 @@ fn convert_nscolor_to_computedcolor(color: nscolor) -> ComputedColor {
     ComputedColor::rgba(convert_nscolor_to_rgba(color))
 }
 
-impl ToComputedValue for Color {
-    type ComputedValue = ComputedColor;
-
-    fn to_computed_value(&self, context: &Context) -> ComputedColor {
+impl Color {
+    /// Converts this Color into a ComputedColor.
+    ///
+    /// If `context` is `None`, and the specified color requires data from
+    /// the context to resolve, then `None` is returned.
+    pub fn to_computed_color(
+        &self,
+        _context: Option<&Context>,
+    ) -> Option<ComputedColor> {
         match *self {
             Color::CurrentColor => {
-                if let Some(longhand) = context.for_non_inherited_property {
-                    if longhand.stores_complex_colors_lossily() {
-                        context.rule_cache_conditions.borrow_mut()
-                            .set_uncacheable();
-                    }
-                }
-                ComputedColor::currentcolor()
+                Some(ComputedColor::currentcolor())
+            }
+            Color::Numeric { ref parsed, .. } => {
+                Some(ComputedColor::rgba(*parsed))
             }
-            Color::Numeric { ref parsed, .. } => ComputedColor::rgba(*parsed),
             Color::Complex(ref complex) => {
-                if complex.foreground_ratio != 0 {
-                    if let Some(longhand) = context.for_non_inherited_property {
-                        if longhand.stores_complex_colors_lossily() {
-                            context.rule_cache_conditions.borrow_mut()
-                                .set_uncacheable();
-                        }
-                    }
-                }
-                *complex
+                Some(*complex)
             }
             #[cfg(feature = "gecko")]
-            Color::System(system) =>
-                convert_nscolor_to_computedcolor(system.to_computed_value(context)),
+            Color::System(system) => {
+                _context.map(|context| {
+                    convert_nscolor_to_computedcolor(
+                        system.to_computed_value(context)
+                    )
+                })
+            }
             #[cfg(feature = "gecko")]
             Color::Special(special) => {
                 use self::gecko::SpecialColorKeyword as Keyword;
-                let pres_context = context.device().pres_context();
-                convert_nscolor_to_computedcolor(match special {
-                    Keyword::MozDefaultColor => pres_context.mDefaultColor,
-                    Keyword::MozDefaultBackgroundColor => pres_context.mBackgroundColor,
-                    Keyword::MozHyperlinktext => pres_context.mLinkColor,
-                    Keyword::MozActiveHyperlinktext => pres_context.mActiveLinkColor,
-                    Keyword::MozVisitedHyperlinktext => pres_context.mVisitedLinkColor,
+                _context.map(|context| {
+                    let pres_context = context.device().pres_context();
+                    convert_nscolor_to_computedcolor(match special {
+                        Keyword::MozDefaultColor => pres_context.mDefaultColor,
+                        Keyword::MozDefaultBackgroundColor => pres_context.mBackgroundColor,
+                        Keyword::MozHyperlinktext => pres_context.mLinkColor,
+                        Keyword::MozActiveHyperlinktext => pres_context.mActiveLinkColor,
+                        Keyword::MozVisitedHyperlinktext => pres_context.mVisitedLinkColor,
+                    })
                 })
             }
             #[cfg(feature = "gecko")]
             Color::InheritFromBodyQuirk => {
-                ComputedColor::rgba(context.device().body_text_color())
+                _context.map(|context| {
+                    ComputedColor::rgba(context.device().body_text_color())
+                })
             },
         }
     }
+}
+
+impl ToComputedValue for Color {
+    type ComputedValue = ComputedColor;
+
+    fn to_computed_value(&self, context: &Context) -> ComputedColor {
+        let result = self.to_computed_color(Some(context)).unwrap();
+        if result.foreground_ratio != 0 {
+            if let Some(longhand) = context.for_non_inherited_property {
+                if longhand.stores_complex_colors_lossily() {
+                    context.rule_cache_conditions.borrow_mut().set_uncacheable();
+                }
+            }
+        }
+        result
+    }
 
     fn from_computed_value(computed: &ComputedColor) -> Self {
         if computed.is_numeric() {
diff --git a/servo/components/webdriver_server/Cargo.toml b/servo/components/webdriver_server/Cargo.toml
index 86df911fa7ca..7c51bf6a7ea9 100644
--- a/servo/components/webdriver_server/Cargo.toml
+++ b/servo/components/webdriver_server/Cargo.toml
@@ -15,7 +15,7 @@ cookie = "0.6"
 euclid = "0.15"
 hyper = "0.10"
 image = "0.16"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 log = "0.3.5"
 msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
diff --git a/servo/components/webvr/Cargo.toml b/servo/components/webvr/Cargo.toml
index 15622da20ad8..c3a5d56b397a 100644
--- a/servo/components/webvr/Cargo.toml
+++ b/servo/components/webvr/Cargo.toml
@@ -16,7 +16,7 @@ oculusvr = ['rust-webvr/oculusvr']
 [dependencies]
 canvas_traits = {path = "../canvas_traits"}
 euclid = "0.15"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 log = "0.3"
 msg = {path = "../msg"}
 rust-webvr = {version = "0.9", features = ["openvr"]}
diff --git a/servo/components/webvr_traits/Cargo.toml b/servo/components/webvr_traits/Cargo.toml
index 8e1b98f058ec..2582d2a3e4b5 100644
--- a/servo/components/webvr_traits/Cargo.toml
+++ b/servo/components/webvr_traits/Cargo.toml
@@ -10,7 +10,7 @@ name = "webvr_traits"
 path = "lib.rs"
 
 [dependencies]
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 msg = {path = "../msg"}
 rust-webvr-api = {version = "0.9", features = ["serde-serialization"]}
 serde = "1.0"
diff --git a/servo/dependencyci.yml b/servo/dependencyci.yml
index 56337afdbc7a..d7a74cffb546 100644
--- a/servo/dependencyci.yml
+++ b/servo/dependencyci.yml
@@ -3,4 +3,8 @@ platforms:
     charade:
       tests:
         removed: skip
-        unmaintained: skip
+        unmaintained: skip # https://github.com/w3c/web-platform-tests/issues/6269
+  cargo:
+    smallbitvec:
+      tests:
+        unlicensed: skip # https://github.com/librariesio/libraries.io/issues/1762
diff --git a/servo/etc/ci/buildbot_steps.yml b/servo/etc/ci/buildbot_steps.yml
index 317077c02874..09438dce9664 100644
--- a/servo/etc/ci/buildbot_steps.yml
+++ b/servo/etc/ci/buildbot_steps.yml
@@ -84,6 +84,7 @@ linux-dev:
   - env SERVO_RUSTC_LLVM_ASSERTIONS=1 ./mach test-unit
   - env SERVO_RUSTC_LLVM_ASSERTIONS=1 ./mach package --dev
   - env SERVO_RUSTC_LLVM_ASSERTIONS=1 ./mach build-cef
+  - env SERVO_RUSTC_LLVM_ASSERTIONS=1 ./mach build --dev --no-default-features --features default-except-unstable
   - ./mach build-geckolib
   - ./mach test-stylo
   - bash ./etc/ci/lockfile_changed.sh
diff --git a/servo/ports/cef/lib.rs b/servo/ports/cef/lib.rs
index ce73994b326b..269d106d1675 100644
--- a/servo/ports/cef/lib.rs
+++ b/servo/ports/cef/lib.rs
@@ -4,7 +4,6 @@
 
 #![allow(non_camel_case_types)]
 #![feature(core_intrinsics)]
-#![feature(link_args)]
 
 #[macro_use]
 extern crate log;
@@ -27,10 +26,6 @@ extern crate webrender_api;
 
 extern crate libc;
 
-#[cfg(target_os="macos")]
-#[link_args="-Xlinker -undefined -Xlinker dynamic_lookup"]
-extern { }
-
 #[cfg(target_os="macos")]
 extern crate cocoa;
 #[cfg(target_os="macos")]
diff --git a/servo/ports/geckolib/glue.rs b/servo/ports/geckolib/glue.rs
index 509d869c625c..9e7c2f22f2d3 100644
--- a/servo/ports/geckolib/glue.rs
+++ b/servo/ports/geckolib/glue.rs
@@ -44,7 +44,7 @@ use style::gecko_bindings::bindings::{RawServoMediaRule, RawServoMediaRuleBorrow
 use style::gecko_bindings::bindings::{RawServoNamespaceRule, RawServoNamespaceRuleBorrowed};
 use style::gecko_bindings::bindings::{RawServoPageRule, RawServoPageRuleBorrowed};
 use style::gecko_bindings::bindings::{RawServoSelectorListBorrowed, RawServoSelectorListOwned};
-use style::gecko_bindings::bindings::{RawServoStyleSetBorrowed, RawServoStyleSetOwned};
+use style::gecko_bindings::bindings::{RawServoStyleSetBorrowed, RawServoStyleSetBorrowedOrNull, RawServoStyleSetOwned};
 use style::gecko_bindings::bindings::{RawServoStyleSheetContentsBorrowed, ServoComputedDataBorrowed};
 use style::gecko_bindings::bindings::{RawServoStyleSheetContentsStrong, ServoStyleContextBorrowed};
 use style::gecko_bindings::bindings::{RawServoSupportsRule, RawServoSupportsRuleBorrowed};
@@ -145,6 +145,7 @@ use style::values::{CustomIdent, KeyframesName};
 use style::values::animated::{Animate, Procedure, ToAnimatedZero};
 use style::values::computed::{Context, ToComputedValue};
 use style::values::distance::ComputeSquaredDistance;
+use style::values::specified;
 use style_traits::{PARSING_MODE_DEFAULT, ToCss};
 use super::error_reporter::ErrorReporter;
 use super::stylesheet_loader::StylesheetLoader;
@@ -4206,3 +4207,66 @@ pub unsafe extern "C" fn Servo_SelectorList_Parse(
 pub unsafe extern "C" fn Servo_SelectorList_Drop(list: RawServoSelectorListOwned) {
     let _ = list.into_box::<::selectors::SelectorList<SelectorImpl>>();
 }
+
+fn parse_color(value: &str) -> Result<specified::Color, ()> {
+    let mut input = ParserInput::new(value);
+    let mut parser = Parser::new(&mut input);
+    parser.parse_entirely(specified::Color::parse_color).map_err(|_| ())
+}
+
+#[no_mangle]
+pub extern "C" fn Servo_IsValidCSSColor(
+    value: *const nsAString,
+) -> bool {
+    let value = unsafe { (*value).to_string() };
+    parse_color(&value).is_ok()
+}
+
+#[no_mangle]
+pub extern "C" fn Servo_ComputeColor(
+    raw_data: RawServoStyleSetBorrowedOrNull,
+    current_color: structs::nscolor,
+    value: *const nsAString,
+    result_color: *mut structs::nscolor,
+) -> bool {
+    use style::gecko;
+
+    let current_color = gecko::values::convert_nscolor_to_rgba(current_color);
+    let value = unsafe { (*value).to_string() };
+    let result_color = unsafe { result_color.as_mut().unwrap() };
+
+    match parse_color(&value) {
+        Ok(specified_color) => {
+            let computed_color = match raw_data {
+                Some(raw_data) => {
+                    let data = PerDocumentStyleData::from_ffi(raw_data).borrow();
+                    let metrics = get_metrics_provider_for_product();
+                    let mut conditions = Default::default();
+                    let context = create_context(
+                        &data,
+                        &metrics,
+                        data.stylist.device().default_computed_values(),
+                        /* parent_style = */ None,
+                        /* pseudo = */ None,
+                        /* for_smil_animation = */ false,
+                        &mut conditions,
+                    );
+                    specified_color.to_computed_color(Some(&context))
+                }
+                None => {
+                    specified_color.to_computed_color(None)
+                }
+            };
+
+            match computed_color {
+                Some(computed_color) => {
+                    let rgba = computed_color.to_rgba(current_color);
+                    *result_color = gecko::values::convert_rgba_to_nscolor(&rgba);
+                    true
+                }
+                None => false,
+            }
+        }
+        Err(_) => false,
+    }
+}
diff --git a/servo/ports/servo/main.rs b/servo/ports/servo/main.rs
index 19063d1176ae..b24737f2d19d 100644
--- a/servo/ports/servo/main.rs
+++ b/servo/ports/servo/main.rs
@@ -15,7 +15,7 @@
 //!
 //! [glutin]: https://github.com/tomaka/glutin
 
-#![feature(core_intrinsics)]
+#![cfg_attr(feature = "unstable", feature(core_intrinsics))]
 
 #[cfg(target_os = "android")]
 extern crate android_injected_glue;
@@ -26,7 +26,7 @@ extern crate glutin_app as app;
 extern crate log;
 // The Servo engine
 extern crate servo;
-#[cfg(not(target_os = "android"))]
+#[cfg(all(feature = "unstable", not(target_os = "android")))]
 #[macro_use]
 extern crate sig;
 
@@ -57,7 +57,7 @@ pub mod platform {
     pub fn deinit() {}
 }
 
-#[cfg(not(target_os = "android"))]
+#[cfg(all(feature = "unstable", not(target_os = "android")))]
 fn install_crash_handler() {
     use backtrace::Backtrace;
     use sig::ffi::Sig;
@@ -83,7 +83,7 @@ fn install_crash_handler() {
     signal!(Sig::BUS, handler); // handle invalid memory access
 }
 
-#[cfg(target_os = "android")]
+#[cfg(any(not(feature = "unstable"), target_os = "android"))]
 fn install_crash_handler() {}
 
 fn main() {
diff --git a/servo/python/servo/build_commands.py b/servo/python/servo/build_commands.py
index 0d0dbc0ebcd3..ec20f18af5a3 100644
--- a/servo/python/servo/build_commands.py
+++ b/servo/python/servo/build_commands.py
@@ -24,7 +24,7 @@ from mach.decorators import (
     Command,
 )
 
-from servo.command_base import CommandBase, cd, call, check_call, BIN_SUFFIX
+from servo.command_base import CommandBase, cd, call, check_call, BIN_SUFFIX, is_macosx
 from servo.util import host_triple
 
 
@@ -401,8 +401,14 @@ class MachCommands(CommandBase):
         if with_debug_assertions:
             env["RUSTFLAGS"] = "-C debug_assertions"
 
+        if is_macosx():
+            # Unlike RUSTFLAGS, these are only passed in the final rustc invocation
+            # so that `./mach build` followed by `./mach build-cef` both build
+            # common dependencies with the same flags.
+            opts += ["--", "-C", "link-args=-Xlinker -undefined -Xlinker dynamic_lookup"]
+
         with cd(path.join("ports", "cef")):
-            ret = call(["cargo", "build"] + opts,
+            ret = call(["cargo", "rustc"] + opts,
                        env=env,
                        verbose=verbose)
         elapsed = time() - build_start
diff --git a/servo/python/servo/util.py b/servo/python/servo/util.py
index b839d9e2ca2c..0a74f9fe7f1d 100644
--- a/servo/python/servo/util.py
+++ b/servo/python/servo/util.py
@@ -37,11 +37,7 @@ def host_platform():
     elif os_type == "android":
         os_type = "linux-androideabi"
     elif os_type == "windows":
-        # If we are in a Visual Studio environment, use msvc
-        if os.getenv("PLATFORM") is not None:
-            os_type = "pc-windows-msvc"
-        else:
-            os_type = "unknown"
+        os_type = "pc-windows-msvc"
     elif os_type == "freebsd":
         os_type = "unknown-freebsd"
     else:
@@ -52,16 +48,7 @@ def host_platform():
 def host_triple():
     os_type = host_platform()
     cpu_type = platform.machine().lower()
-    if os_type.endswith("-msvc"):
-        # vcvars*.bat should set it properly
-        platform_env = os.environ.get("PLATFORM").upper()
-        if platform_env == "X86":
-            cpu_type = "i686"
-        elif platform_env == "X64":
-            cpu_type = "x86_64"
-        else:
-            cpu_type = "unknown"
-    elif cpu_type in ["i386", "i486", "i686", "i768", "x86"]:
+    if cpu_type in ["i386", "i486", "i686", "i768", "x86"]:
         cpu_type = "i686"
     elif cpu_type in ["x86_64", "x86-64", "x64", "amd64"]:
         cpu_type = "x86_64"
diff --git a/servo/resources/prefs.json b/servo/resources/prefs.json
index 74d2302f68c9..f5d85ae9dc68 100644
--- a/servo/resources/prefs.json
+++ b/servo/resources/prefs.json
@@ -15,6 +15,7 @@
   "dom.servoparser.async_html_tokenizer.enabled": false,
   "dom.testable_crash.enabled": false,
   "dom.testbinding.enabled": false,
+  "dom.webgl.dom_to_texture.enabled": false,
   "dom.webvr.enabled": false,
   "dom.webvr.event_polling_interval": 500,
   "js.asmjs.enabled": true,
diff --git a/servo/tests/unit/gfx/Cargo.toml b/servo/tests/unit/gfx/Cargo.toml
index da081e341ff8..b759f13422e8 100644
--- a/servo/tests/unit/gfx/Cargo.toml
+++ b/servo/tests/unit/gfx/Cargo.toml
@@ -12,5 +12,5 @@ doctest = false
 [dependencies]
 cssparser = "0.22.0"
 gfx = {path = "../../../components/gfx"}
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 style = {path = "../../../components/style"}
diff --git a/servo/tests/unit/metrics/Cargo.toml b/servo/tests/unit/metrics/Cargo.toml
index 4cf1c52991f8..3c5aabccb2ec 100644
--- a/servo/tests/unit/metrics/Cargo.toml
+++ b/servo/tests/unit/metrics/Cargo.toml
@@ -13,7 +13,7 @@ doctest = false
 euclid = "0.15"
 gfx = {path = "../../../components/gfx"}
 gfx_traits = {path = "../../../components/gfx_traits"}
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 metrics = {path = "../../../components/metrics"}
 msg = {path = "../../../components/msg"}
 net_traits = {path = "../../../components/net_traits"}
diff --git a/servo/tests/unit/net/Cargo.toml b/servo/tests/unit/net/Cargo.toml
index f48abf6bb47e..6c50275cfad8 100644
--- a/servo/tests/unit/net/Cargo.toml
+++ b/servo/tests/unit/net/Cargo.toml
@@ -16,7 +16,7 @@ flate2 = "0.2.0"
 hyper = "0.10"
 hyper-openssl = "0.2"
 hyper_serde = "0.7"
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 msg = {path = "../../../components/msg"}
 net = {path = "../../../components/net"}
 net_traits = {path = "../../../components/net_traits"}
diff --git a/servo/tests/unit/profile/Cargo.toml b/servo/tests/unit/profile/Cargo.toml
index b52b947696ac..36dbeb8ffb14 100644
--- a/servo/tests/unit/profile/Cargo.toml
+++ b/servo/tests/unit/profile/Cargo.toml
@@ -10,6 +10,6 @@ path = "lib.rs"
 doctest = false
 
 [dependencies]
-ipc-channel = "0.8"
+ipc-channel = "0.9"
 profile = {path = "../../../components/profile"}
 profile_traits = {path = "../../../components/profile_traits"}
diff --git a/servo/tests/unit/style/lib.rs b/servo/tests/unit/style/lib.rs
index c1eab17d1b60..98ed3a9edd65 100644
--- a/servo/tests/unit/style/lib.rs
+++ b/servo/tests/unit/style/lib.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #![cfg(test)]
-#![feature(plugin, test)]
+#![feature(test)]
 
 extern crate app_units;
 extern crate cssparser;
diff --git a/taskcluster/ci/build/windows.yml b/taskcluster/ci/build/windows.yml
index 2feaba3cfb87..2cee59774df7 100755
--- a/taskcluster/ci/build/windows.yml
+++ b/taskcluster/ci/build/windows.yml
@@ -528,7 +528,7 @@ win32-mingw32/debug:
     treeherder:
         platform: windows-mingw32-32/debug
         symbol: tc(B)
-        tier: 3
+        tier: 2
     worker-type: aws-provisioner-v1/gecko-{level}-b-linux
     worker:
         max-run-time: 7200
diff --git a/taskcluster/ci/nightly-l10n/kind.yml b/taskcluster/ci/nightly-l10n/kind.yml
index 7ca8ef50e4a6..85bb965f1c74 100644
--- a/taskcluster/ci/nightly-l10n/kind.yml
+++ b/taskcluster/ci/nightly-l10n/kind.yml
@@ -157,12 +157,14 @@ job-template:
                - platform-config=single_locale/win32.py
                - config=single_locale/tc_win32.py
                - config=taskcluster_nightly.py
+               - revision=$GECKO_HEAD_REV
             win64-nightly:
                - environment-config=single_locale/production.py
                - branch-config=single_locale/{project}.py
                - platform-config=single_locale/win64.py
                - config=single_locale/tc_win64.py
                - config=taskcluster_nightly.py
+               - revision=$GECKO_HEAD_REV
             default: [ ]
       actions:
          by-build-platform:
diff --git a/taskcluster/ci/source-test/mozlint.yml b/taskcluster/ci/source-test/mozlint.yml
index b2b780e47906..3474c8c65cbb 100644
--- a/taskcluster/ci/source-test/mozlint.yml
+++ b/taskcluster/ci/source-test/mozlint.yml
@@ -1,14 +1,24 @@
-eslint:
-    description: JS lint check
-    platform: lint/opt
+job-defaults:
     treeherder:
-        symbol: ES
         kind: test
         tier: 1
     worker-type: aws-provisioner-v1/gecko-t-linux-xlarge
     worker:
         docker-image: {in-tree: "lint"}
         max-run-time: 1800
+    run:
+        using: mach
+    when:
+        files-changed:
+            # Other misc lint related files.
+            - 'python/mozlint/**'
+            - 'tools/lint/**'
+
+eslint:
+    description: JS lint check
+    platform: lint/opt
+    treeherder:
+        symbol: ES
     run:
         using: run-task
         command: >
@@ -32,65 +42,37 @@ eslint:
             # The plugin implementing custom checks.
             - 'tools/lint/eslint/eslint-plugin-mozilla/**'
             - 'tools/lint/eslint/eslint-plugin-spidermonkey-js/**'
-            # Other misc lint related files.
-            - 'python/mozlint/**'
-            - 'tools/lint/**'
 
 py-compat:
     description: lint for python 2/3 compatibility issues
     platform: lint/opt
     treeherder:
         symbol: py-compat
-        kind: test
-        tier: 1
-    worker-type: aws-provisioner-v1/gecko-t-linux-xlarge
-    worker:
-        docker-image: {in-tree: "lint"}
-        max-run-time: 1800
     run:
-        using: mach
         mach: lint -l py2 -l py3 -f treeherder
     when:
         files-changed:
             - '**/*.py'
             - '**/.flake8'
-            - 'python/mozlint/**'
-            - 'tools/lint/**'
 
 py-flake8:
     description: flake8 run over the gecko codebase
     platform: lint/opt
     treeherder:
         symbol: f8
-        kind: test
-        tier: 1
-    worker-type: aws-provisioner-v1/gecko-t-linux-xlarge
-    worker:
-        docker-image: {in-tree: "lint"}
-        max-run-time: 1800
     run:
-        using: mach
         mach: lint -l flake8 -f treeherder
     when:
         files-changed:
             - '**/*.py'
             - '**/.flake8'
-            - 'python/mozlint/**'
-            - 'tools/lint/**'
 
 test-manifest:
     description: lint test manifests
     platform: lint/opt
     treeherder:
         symbol: tm
-        kind: test
-        tier: 1
-    worker-type: aws-provisioner-v1/gecko-t-linux-xlarge
-    worker:
-        docker-image: {in-tree: "lint"}
-        max-run-time: 1800
     run:
-        using: mach
         mach: lint -l test-disable -f treeherder
     when:
         files-changed:
@@ -103,14 +85,7 @@ wptlint-gecko:
     platform: lint/opt
     treeherder:
         symbol: W
-        kind: test
-        tier: 1
-    worker-type: aws-provisioner-v1/gecko-t-linux-xlarge
-    worker:
-        docker-image: {in-tree: "lint"}
-        max-run-time: 1800
     run:
-        using: mach
         mach: lint -l wpt -l wpt_manifest -f treeherder
     when:
         files-changed:
@@ -118,27 +93,16 @@ wptlint-gecko:
             - 'testing/web-platform/mozilla/tests/**'
             - 'testing/web-platform/meta/MANIFEST.json'
             - 'testing/web-platform/mozilla/meta/MANIFEST.json'
-            - 'python/mozlint/**'
-            - 'tools/lint/**'
 
 yaml:
     description: yamllint run over the gecko codebase
     platform: lint/opt
     treeherder:
         symbol: yaml
-        kind: test
-        tier: 1
-    worker-type: aws-provisioner-v1/gecko-t-linux-xlarge
-    worker:
-        docker-image: {in-tree: "lint"}
-        max-run-time: 1800
     run:
-        using: mach
         mach: lint -l yaml -f treeherder
     when:
         files-changed:
             - '**/*.yml'
             - '**/*.yaml'
             - '**/.ymllint'
-            - 'python/mozlint/**'
-            - 'tools/lint/**'
diff --git a/taskcluster/ci/source-test/python.yml b/taskcluster/ci/source-test/python.yml
index 96804bec1f18..2eba4a2cdd8a 100644
--- a/taskcluster/ci/source-test/python.yml
+++ b/taskcluster/ci/source-test/python.yml
@@ -1,40 +1,42 @@
-taskgraph-tests:
-    description: taskcluster/taskgraph unit tests
+job-defaults:
     platform: linux64/opt
+    worker-type:
+        by-platform:
+            linux64.*: aws-provisioner-v1/gecko-t-linux-xlarge
     treeherder:
-        symbol: py(tg)
         kind: test
         tier: 2
-    worker-type: aws-provisioner-v1/gecko-t-linux-xlarge
+    run:
+        using: mach
+    when:
+        files-changed:
+            - 'config/mozunit.py'
+            - 'python/mach_commands.py'
+
+taskgraph-tests:
+    description: taskcluster/taskgraph unit tests
+    treeherder:
+        symbol: py(tg)
     worker:
         docker-image: {in-tree: "lint"}
         max-run-time: 1800
     run:
-        using: mach
         mach: python-test --subsuite taskgraph
     when:
         files-changed:
             - 'taskcluster/**/*.py'
-            - 'config/mozunit.py'
             - 'python/mach/**/*.py'
 
 marionette-harness:
     description: testing/marionette/harness unit tests
-    platform: linux64/opt
     treeherder:
         symbol: py(mnh)
-        kind: test
-        tier: 2
-    worker-type:
-        by-platform:
-            linux64.*: aws-provisioner-v1/gecko-t-linux-xlarge
     worker:
         by-platform:
             linux64.*:
                 docker-image: {in-tree: "lint"}
                 max-run-time: 3600
     run:
-        using: mach
         mach: python-test --subsuite marionette-harness
     when:
         files-changed:
@@ -42,7 +44,6 @@ marionette-harness:
           - 'testing/mozbase/mozlog/mozlog/**'
           - 'testing/mozbase/mozlog/setup.py'
           - 'testing/mozbase/packages.txt'
-          - 'python/mach_commands.py'
 
 mochitest-harness:
     description: testing/mochitest unittests
@@ -53,11 +54,6 @@ mochitest-harness:
     require-build: true
     treeherder:
         symbol: py(mch)
-        kind: test
-        tier: 2
-    worker-type:
-        by-platform:
-            linux64.*: aws-provisioner-v1/gecko-t-linux-xlarge
     worker:
         by-platform:
             linux64.*:
@@ -72,8 +68,6 @@ mochitest-harness:
             ./mach python-test --subsuite mochitest
     when:
         files-changed:
-            - 'config/mozunit.py'
-            - 'python/mach_commands.py'
             - 'testing/mochitest/**'
             - 'testing/mozbase/moztest/moztest/selftest/**'
             - 'testing/mozharness/mozharness/base/log.py'
@@ -87,33 +81,22 @@ mozbase:
         - linux64/opt
     treeherder:
         symbol: py(mb)
-        kind: test
-        tier: 2
-    worker-type:
-        by-platform:
-            linux64.*: aws-provisioner-v1/gecko-t-linux-xlarge
     worker:
         by-platform:
             linux64.*:
                 docker-image: {in-tree: "lint"}
                 max-run-time: 3600
     run:
-        using: mach
         mach: python-test --subsuite mozbase
     when:
         files-changed:
             - 'testing/mozbase/**'
-            - 'config/mozunit.py'
-            - 'python/mach_commands.py'
 
 mozharness:
     description: mozharness integration tests
     platform: linux64/opt
     treeherder:
         symbol: py(mh)
-        kind: test
-        tier: 2
-    worker-type: aws-provisioner-v1/gecko-t-linux-xlarge
     worker:
         docker-image: {in-tree: "lint"}
         max-run-time: 1800
@@ -132,46 +115,32 @@ mozlint:
     platform: linux64/opt
     treeherder:
         symbol: py(ml)
-        kind: test
-        tier: 2
-    worker-type:
-        by-platform:
-            linux64.*: aws-provisioner-v1/gecko-t-linux-xlarge
     worker:
         by-platform:
             linux64.*:
                 docker-image: {in-tree: "lint"}
                 max-run-time: 3600
     run:
-        using: mach
         mach: python-test --subsuite mozlint
     when:
         files-changed:
             - 'python/mozlint/**'
-            - 'python/mach_commands.py'
 
 mozversioncontrol:
     description: python/mozversioncontrol unit tests
     platform: linux64/opt
     treeherder:
         symbol: py(vcs)
-        kind: test
-        tier: 2
-    worker-type:
-        by-platform:
-            linux64.*: aws-provisioner-v1/gecko-t-linux-xlarge
     worker:
         by-platform:
             linux64.*:
                 docker-image: {in-tree: "lint"}
                 max-run-time: 3600
     run:
-        using: mach
         mach: python-test --subsuite mozversioncontrol
     when:
         files-changed:
             - 'python/mozversioncontrol/**'
-            - 'python/mach_commands.py'
 
 reftest-harness:
     description: layout/tools/reftest unittests
@@ -182,11 +151,6 @@ reftest-harness:
     require-build: true
     treeherder:
         symbol: py(ref)
-        kind: test
-        tier: 2
-    worker-type:
-        by-platform:
-            linux64.*: aws-provisioner-v1/gecko-t-linux-xlarge
     worker:
         by-platform:
             linux64.*:
@@ -201,9 +165,7 @@ reftest-harness:
             ./mach python-test --subsuite reftest
     when:
         files-changed:
-            - 'config/mozunit.py'
             - 'layout/tools/reftest/**'
-            - 'python/mach_commands.py'
             - 'testing/mozbase/moztest/moztest/selftest/**'
             - 'testing/mozharness/mozharness/base/log.py'
             - 'testing/mozharness/mozharness/mozilla/structuredlog.py'
diff --git a/taskcluster/ci/test/tests.yml b/taskcluster/ci/test/tests.yml
index 81cc4ca1b623..908e4af5ecb2 100644
--- a/taskcluster/ci/test/tests.yml
+++ b/taskcluster/ci/test/tests.yml
@@ -128,7 +128,7 @@ crashtest:
             default: 1
     e10s:
         by-test-platform:
-            windows7-32/debug: both
+            windows10-64/debug: both
             default: true
     mozharness:
         by-test-platform:
@@ -317,7 +317,7 @@ jsreftest:
     e10s:
         by-test-platform:
             linux64-jsdcov/opt: false
-            windows7-32/debug: both
+            windows10-64/debug: both
             default: true
     max-run-time:
         by-test-platform:
@@ -973,7 +973,7 @@ reftest:
             default: 8
     e10s:
         by-test-platform:
-            windows7-32/debug: both
+            windows10-64/debug: both
             default: true
     max-run-time:
         by-test-platform:
@@ -1062,7 +1062,7 @@ reftest-no-accel:
     e10s:
         by-test-platform:
             linux64-jsdcov/opt: false
-            windows7-32/debug: both
+            windows10-64/debug: both
             default: true
     mozharness:
         script: desktop_unittest.py
diff --git a/taskcluster/ci/toolchain/linux.yml b/taskcluster/ci/toolchain/linux.yml
index cbffc2cde3d4..2e301c81f0d7 100755
--- a/taskcluster/ci/toolchain/linux.yml
+++ b/taskcluster/ci/toolchain/linux.yml
@@ -301,7 +301,7 @@ linux64-android-gradle-dependencies:
         - linux64-android-sdk-linux-repack
         - linux64-proguard-jar-repack
 
-linux64-rust-1.20:
+linux64-rust-1.21:
     description: "rust repack"
     treeherder:
         kind: build
@@ -318,7 +318,7 @@ linux64-rust-1.20:
         using: toolchain-script
         script: repack_rust.py
         arguments: [
-            '--channel', '1.20.0',
+            '--channel', '1.21.0',
             '--host', 'x86_64-unknown-linux-gnu',
             '--target', 'x86_64-unknown-linux-gnu',
             '--target', 'i686-unknown-linux-gnu',
@@ -326,6 +326,30 @@ linux64-rust-1.20:
         toolchain-alias: linux64-rust
         toolchain-artifact: public/build/rustc.tar.xz
 
+linux64-rust-1.20:
+    description: "rust repack"
+    treeherder:
+        kind: build
+        platform: toolchains/opt
+        symbol: TL(rust-1.20)
+        tier: 1
+    worker-type: aws-provisioner-v1/gecko-{level}-b-linux
+    worker:
+        docker-image: {in-tree: desktop-build}
+        max-run-time: 7200
+        env:
+          UPLOAD_DIR: artifacts
+    run:
+        using: toolchain-script
+        script: repack_rust.py
+        arguments: [
+            '--channel', '1.20.0',
+            '--host', 'x86_64-unknown-linux-gnu',
+            '--target', 'x86_64-unknown-linux-gnu',
+            '--target', 'i686-unknown-linux-gnu',
+        ]
+        toolchain-artifact: public/build/rustc.tar.xz
+
 linux64-rust-1.19:
     description: "rust repack"
     treeherder:
@@ -350,7 +374,7 @@ linux64-rust-1.19:
         ]
         toolchain-artifact: public/build/rustc.tar.xz
 
-linux64-rust-macos-1.20:
+linux64-rust-macos-1.21:
     description: "rust repack with macos-cross support"
     treeherder:
         kind: build
@@ -367,7 +391,7 @@ linux64-rust-macos-1.20:
         using: toolchain-script
         script: repack_rust.py
         arguments: [
-           '--channel', '1.20.0',
+           '--channel', '1.21.0',
            '--host', 'x86_64-unknown-linux-gnu',
            '--target', 'x86_64-unknown-linux-gnu',
            '--target', 'x86_64-apple-darwin',
@@ -375,7 +399,7 @@ linux64-rust-macos-1.20:
         toolchain-alias: linux64-rust-macos
         toolchain-artifact: public/build/rustc.tar.xz
 
-linux64-rust-android-1.20:
+linux64-rust-android-1.21:
     description: "rust repack with android-cross support"
     treeherder:
         kind: build
@@ -392,7 +416,7 @@ linux64-rust-android-1.20:
         using: toolchain-script
         script: repack_rust.py
         arguments: [
-           '--channel', '1.20.0',
+           '--channel', '1.21.0',
            '--host', 'x86_64-unknown-linux-gnu',
            '--target', 'x86_64-unknown-linux-gnu',
            '--target', 'armv7-linux-androideabi',
diff --git a/taskcluster/ci/toolchain/windows.yml b/taskcluster/ci/toolchain/windows.yml
index 5e5f67597c2e..eba6555b52ad 100755
--- a/taskcluster/ci/toolchain/windows.yml
+++ b/taskcluster/ci/toolchain/windows.yml
@@ -94,7 +94,7 @@ win64-clang-tidy:
             - 'taskcluster/scripts/misc/build-clang-windows-helper64.sh'
         toolchain-artifact: public/build/clang-tidy.tar.bz2
 
-win64-rust-1.20:
+win64-rust-1.21:
     description: "rust repack"
     treeherder:
         kind: build
@@ -111,7 +111,7 @@ win64-rust-1.20:
         using: toolchain-script
         script: repack_rust.py
         arguments: [
-          '--channel', '1.20.0',
+          '--channel', '1.21.0',
           '--host', 'x86_64-pc-windows-msvc',
           '--target', 'x86_64-pc-windows-msvc',
         ]
@@ -141,7 +141,7 @@ win64-rust-1.19:
         ]
         toolchain-artifact: public/build/rustc.tar.bz2
 
-win32-rust-1.20:
+win32-rust-1.21:
     description: "rust repack"
     treeherder:
         kind: build
@@ -158,14 +158,14 @@ win32-rust-1.20:
         using: toolchain-script
         script: repack_rust.py
         arguments: [
-          '--channel', '1.20.0',
+          '--channel', '1.21.0',
           '--host', 'i686-pc-windows-msvc',
           '--target', 'i686-pc-windows-msvc',
         ]
         toolchain-alias: win32-rust
         toolchain-artifact: public/build/rustc.tar.bz2
 
-mingw32-rust-1.20:
+mingw32-rust-1.21:
     description: "rust repack"
     treeherder:
         kind: build
@@ -182,7 +182,7 @@ mingw32-rust-1.20:
         using: toolchain-script
         script: repack_rust.py
         arguments: [
-          '--channel', '1.20.0',
+          '--channel', '1.21.0',
           '--host', 'i686-unknown-linux-gnu',
           '--target', 'i686-pc-windows-gnu',
           '--target', 'x86_64-unknown-linux-gnu',
diff --git a/taskcluster/scripts/misc/build-gcc-mingw32.sh b/taskcluster/scripts/misc/build-gcc-mingw32.sh
index d963743583ce..2bb270083213 100755
--- a/taskcluster/scripts/misc/build-gcc-mingw32.sh
+++ b/taskcluster/scripts/misc/build-gcc-mingw32.sh
@@ -42,6 +42,7 @@ ca498c1c7a74dd37a576f353312d1e68d490978de4395fa28f1cbd46a364e658  mpfr-3.1.5.tar
 EOF
 
 prepare
+prepare_mingw
 build_binutils
 build_gcc_and_mingw
 
diff --git a/taskcluster/taskgraph/loader/transform.py b/taskcluster/taskgraph/loader/transform.py
index 8864f09554b8..ee07a1136232 100644
--- a/taskcluster/taskgraph/loader/transform.py
+++ b/taskcluster/taskgraph/loader/transform.py
@@ -23,9 +23,10 @@ def loader(kind, path, config, params, loaded_tasks):
     keys to those mappings are added in the `name` key of each entity.
 
     If there is a `job-defaults` config, then every job is merged with it.
-    This provides a simple way to set default values for all jobs of a
-    kind.  More complex defaults should be implemented with custom
-    transforms.
+    This provides a simple way to set default values for all jobs of a kind.
+    The `job-defaults` key can also be specified in a yaml file pointed to by
+    `jobs-from`. In this case it will only apply to tasks defined in the same
+    file.
 
     Other kind implementations can use a different loader function to
     produce inputs and hand them to `transform_inputs`.
@@ -39,9 +40,15 @@ def loader(kind, path, config, params, loaded_tasks):
             yield name, job
 
         for filename in config.get('jobs-from', []):
-            for name, job in load_yaml(path, filename).iteritems():
-                if defaults:
-                    job = merge(defaults, job)
+            tasks = load_yaml(path, filename)
+
+            file_defaults = tasks.pop('job-defaults', None)
+            if defaults:
+                file_defaults = merge(defaults, file_defaults or {})
+
+            for name, job in tasks.iteritems():
+                if file_defaults:
+                    job = merge(file_defaults, job)
                 job['job-from'] = filename
                 yield name, job
 
diff --git a/taskcluster/taskgraph/target_tasks.py b/taskcluster/taskgraph/target_tasks.py
index 24980dd96081..51fe3a911211 100644
--- a/taskcluster/taskgraph/target_tasks.py
+++ b/taskcluster/taskgraph/target_tasks.py
@@ -302,6 +302,10 @@ def target_tasks_candidates_fennec(full_task_graph, parameters):
     filtered_for_project = target_tasks_nightly_fennec(full_task_graph, parameters)
 
     def filter(task):
+        attr = task.attributes.get
+        # Don't ship single locale fennec anymore - Bug 1408083
+        if attr("locale") or attr("chunk_locales"):
+            return False
         if task.kind not in ['balrog']:
             return task.attributes.get('nightly', False)
 
diff --git a/testing/geckodriver/doc/TraceLogs.md b/testing/geckodriver/doc/TraceLogs.md
index 1eb238be10e5..ff443165b25f 100644
--- a/testing/geckodriver/doc/TraceLogs.md
+++ b/testing/geckodriver/doc/TraceLogs.md
@@ -165,7 +165,7 @@ Ruby
 The Selenium [Ruby client] comes with an [`Options`] helper to
 generate the correct [`moz:firefoxOptions`] capabilities object:
 
-	Selenium::WebDriver.logger.level = :trace
+	Selenium::WebDriver.logger.level = :debug
 	opts = Selenium::WebDriver::Firefox::Options.new(log_level: :trace)
 	driver = Selenium::WebDriver.for :firefox, options: opts
 
diff --git a/testing/marionette/README.md b/testing/marionette/README.md
index a956b1df9e57..9cefa5175519 100644
--- a/testing/marionette/README.md
+++ b/testing/marionette/README.md
@@ -31,118 +31,6 @@ This binds to a TCP socket, over which [clients] can communicate
 with Marionette using the [protocol].
 
 
-Protocol
-========
-
-Marionette provides an asynchronous, parallel pipelining user-facing
-interface.  Message sequencing limits chances of payload race
-conditions and provides a uniform way in which payloads are serialised.
-
-Clients that deliver a blocking WebDriver interface are still
-expected to not send further command requests before the response
-from the last command has come back, but if they still happen to do
-so because of programming error, no harm will be done.  This guards
-against [mixing up responses].
-
-Schematic flow of messages:
-
-	               client      server
-	                 |            |
-	      msgid=1    |----------->|
-	                 |  command   |
-	                 |            |
-	      msgid=2    |<-----------|
-	                 |  command   |
-	                 |            |
-	      msgid=2    |----------->|
-	                 |  response  |
-	                 |            |
-	      msgid=1    |<-----------|
-	                 |  response  |
-	                 |            |
-
-The protocol consists of a [command] message and the corresponding
-[response] message.  A [response] message must always be sent in
-reply to a [commmand] message.
-
-This means that the server implementation does not need to send
-the reply precisely in the order of the received commands: if it
-receives multiple messages, the server may even reply in random order.
-It is therefore strongly adviced that clients take this into account
-when imlpementing the client end of this wire protocol.
-
-This is required for pipelining messages.  On the server side,
-some functions are fast, and some less so.  If the server must
-reply in order, the slow functions delay the other replies even if
-its execution is already completed.
-
-[mixing up responses]: https://bugzil.la/1207125
-
-
-Command
--------
-
-The request, or command message, is a four element JSON Array as shown
-below, that may originate from either the client- or server remote ends:
-
-	[type, message ID, command, parameters]
-
-  * _type_ must be 0 (integer).  This indicates that the message
-    is a [command].
-
-  * _message ID_ is a 32-bit unsigned integer.  This number is
-    used as a sequencing number that uniquely identifies a pair of
-    [command] and [response] messages.  The other remote part will
-    reply with a corresponding [response] with the same message ID.
-
-  * _command_ is a string identifying the RPC method or command
-    to execute.
-
-  * _parameters_ is an arbitrary JSON serialisable object.
-
-
-Response
---------
-
-The response message is also a four element array as shown below,
-and must always be sent after receiving a [command]:
-
-	[type, message ID, error, result]
-
-  * _type_ must be 1 (integer).  This indicates that the message is a
-    [response].
-
-  * _message ID_ is a 32-bit unsigned integer.  This corresponds
-    to the [command]’s message ID.
-
-  * _error_ is null if the command executed correctly.  If the
-    error occurred on the server-side, then this is an [error] object.
-
-  * _result_ is the result object from executing the [command], iff
-    it executed correctly.  If an error occurred on the server-side,
-    this field is null.
-
-The structure of the result field can vary, but is documented
-individually for each command.
-
-
-Error object
-------------
-
-An error object is a serialisation of JavaScript error types,
-and it is structured like this:
-
-	{
-		"error": "invalid session id",
-		"message": "No active session with ID 1234",
-		"stacktrace": ""
-	}
-
-All the fields of the error object are required, so the stacktrace and
-message fields may be empty strings.  The error field is guaranteed
-to be one of the JSON error codes as laid out by the [WebDriver standard].
-
-
 Clients
 =======
 
diff --git a/testing/marionette/client/marionette_driver/marionette.py b/testing/marionette/client/marionette_driver/marionette.py
index e496afafcfc0..76af376393d0 100644
--- a/testing/marionette/client/marionette_driver/marionette.py
+++ b/testing/marionette/client/marionette_driver/marionette.py
@@ -177,8 +177,7 @@ class HTMLElement(object):
             of the DOMRect of the ``HTMLElement``.
         """
         body = {"id": self.id}
-        return self.marionette._send_message(
-            "getElementRect", body, key="value" if self.marionette.protocol == 1 else None)
+        return self.marionette._send_message("getElementRect", body)
 
     def value_of_css_property(self, property_name):
         """Gets the value of the specified CSS property name.
@@ -741,15 +740,7 @@ class Marionette(object):
             raise errors.MarionetteException("Please start a session")
 
         try:
-            if self.protocol < 3:
-                data = {"name": name}
-                if params is not None:
-                    data["parameters"] = params
-                self.client.send(data)
-                msg = self.client.receive()
-
-            else:
-                msg = self.client.request(name, params)
+            msg = self.client.request(name, params)
 
         except IOError:
             self.delete_session(send_request=False)
@@ -777,18 +768,9 @@ class Marionette(object):
             return value
 
     def _handle_error(self, obj):
-        if self.protocol == 1:
-            if "error" not in obj or not isinstance(obj["error"], dict):
-                raise errors.MarionetteException(
-                    "Malformed packet, expected key 'error' to be a dict: {}".format(obj))
-            error = obj["error"].get("status")
-            message = obj["error"].get("message")
-            stacktrace = obj["error"].get("stacktrace")
-
-        else:
-            error = obj["error"]
-            message = obj["message"]
-            stacktrace = obj["stacktrace"]
+        error = obj["error"]
+        message = obj["message"]
+        stacktrace = obj["stacktrace"]
 
         raise errors.lookup(error)(message, stacktrace=stacktrace)
 
@@ -1260,7 +1242,7 @@ class Marionette(object):
 
         resp = self._send_message("newSession", body)
         self.session_id = resp["sessionId"]
-        self.session = resp["value"] if self.protocol == 1 else resp["capabilities"]
+        self.session = resp["capabilities"]
         # fallback to processId can be removed in Firefox 55
         self.process_id = self.session.get("moz:processID", self.session.get("processId"))
         self.profile = self.session.get("moz:profile")
@@ -1404,8 +1386,7 @@ class Marionette(object):
         """
         warnings.warn("get_window_position() has been deprecated, please use get_window_rect()",
                       DeprecationWarning)
-        return self._send_message(
-            "getWindowPosition", key="value" if self.protocol == 1 else None)
+        return self._send_message("getWindowPosition")
 
     def set_window_position(self, x, y):
         """Set the position of the current window
@@ -1461,8 +1442,7 @@ class Marionette(object):
 
         :returns: Unordered list of unique window handles as strings
         """
-        return self._send_message(
-            "getWindowHandles", key="value" if self.protocol == 1 else None)
+        return self._send_message("getWindowHandles")
 
     @property
     def chrome_window_handles(self):
@@ -1473,8 +1453,7 @@ class Marionette(object):
 
         :returns: Unordered list of unique chrome window handles as strings
         """
-        return self._send_message(
-            "getChromeWindowHandles", key="value" if self.protocol == 1 else None)
+        return self._send_message("getChromeWindowHandles")
 
     @property
     def page_source(self):
@@ -1903,13 +1882,10 @@ class Marionette(object):
         body = {"value": target, "using": method}
         if id:
             body["element"] = id
-        return self._send_message(
-            "findElements", body, key="value" if self.protocol == 1 else None)
+        return self._send_message("findElements", body)
 
     def get_active_element(self):
         el_or_ref = self._send_message("getActiveElement", key="value")
-        if self.protocol < 3:
-            return HTMLElement(self, el_or_ref)
         return el_or_ref
 
     def add_cookie(self, cookie):
@@ -1975,7 +1951,7 @@ class Marionette(object):
 
         :returns: A list of cookies for the current domain.
         """
-        return self._send_message("getCookies", key="value" if self.protocol == 1 else None)
+        return self._send_message("getCookies")
 
     def screenshot(self, element=None, highlights=None, format="base64",
                    full=True, scroll=True):
@@ -2070,8 +2046,7 @@ class Marionette(object):
         """
         warnings.warn("window_size property has been deprecated, please use get_window_rect()",
                       DeprecationWarning)
-        return self._send_message("getWindowSize",
-                                  key="value" if self.protocol == 1 else None)
+        return self._send_message("getWindowSize")
 
     def set_window_size(self, width, height):
         """Resize the browser window currently in focus.
diff --git a/testing/marionette/client/marionette_driver/transport.py b/testing/marionette/client/marionette_driver/transport.py
index c3f8f9af26bf..55ed0be3329f 100644
--- a/testing/marionette/client/marionette_driver/transport.py
+++ b/testing/marionette/client/marionette_driver/transport.py
@@ -77,33 +77,6 @@ class Response(Message):
         return Response(data[1], data[2], data[3])
 
 
-class Proto2Command(Command):
-    """Compatibility shim that marshals messages from a protocol level
-    2 and below remote into ``Command`` objects.
-    """
-
-    def __init__(self, name, params):
-        Command.__init__(self, None, name, params)
-
-
-class Proto2Response(Response):
-    """Compatibility shim that marshals messages from a protocol level
-    2 and below remote into ``Response`` objects.
-    """
-
-    def __init__(self, error, result):
-        Response.__init__(self, None, error, result)
-
-    @staticmethod
-    def from_data(data):
-        err, res = None, None
-        if "error" in data:
-            err = data
-        else:
-            res = data
-        return Proto2Response(err, res)
-
-
 class TcpTransport(object):
     """Socket client that communciates with Marionette via TCP.
 
@@ -114,9 +87,10 @@ class TcpTransport(object):
 
     On top of this protocol it uses a Marionette message format, that
     depending on the protocol level offered by the remote server, varies.
-    Supported protocol levels are 1 and above.
+    Supported protocol levels are `min_protocol_level` and above.
     """
     max_packet_length = 4096
+    min_protocol_level = 3
 
     def __init__(self, addr, port, socket_timeout=60.0):
         """If `socket_timeout` is `0` or `0.0`, non-blocking socket mode
@@ -127,7 +101,7 @@ class TcpTransport(object):
         self.port = port
         self._socket_timeout = socket_timeout
 
-        self.protocol = 1
+        self.protocol = self.min_protocol_level
         self.application_type = None
         self.last_id = 0
         self.expected_response = None
@@ -154,12 +128,6 @@ class TcpTransport(object):
             elif typ == Response.TYPE:
                 msg = Response.from_msg(packet)
 
-        # protocol 2 and below
-        else:
-            data = json.loads(packet)
-
-            msg = Proto2Response.from_data(data)
-
         return msg
 
     def receive(self, unmarshal=True):
@@ -193,13 +161,10 @@ class TcpTransport(object):
                         msg = self._unmarshal(remaining)
                         self.last_id = msg.id
 
-                        if self.protocol >= 3:
-                            self.last_id = msg.id
-
-                            # keep reading incoming responses until
-                            # we receive the user's expected response
-                            if isinstance(msg, Response) and msg != self.expected_response:
-                                return self.receive(unmarshal)
+                        # keep reading incoming responses until
+                        # we receive the user's expected response
+                        if isinstance(msg, Response) and msg != self.expected_response:
+                            return self.receive(unmarshal)
 
                         return msg
 
@@ -232,7 +197,7 @@ class TcpTransport(object):
             # which we can use to tell which protocol level we are at
             raw = self.receive(unmarshal=False)
         hello = json.loads(raw)
-        self.protocol = hello.get("marionetteProtocol", 1)
+        self.protocol = hello.get("marionetteProtocol", self.min_protocol_level)
         self.application_type = hello.get("applicationType")
 
         return (self.protocol, self.application_type)
diff --git a/testing/marionette/doc/Debugging.md b/testing/marionette/doc/Debugging.md
new file mode 100644
index 000000000000..db09b2bebbcf
--- /dev/null
+++ b/testing/marionette/doc/Debugging.md
@@ -0,0 +1,64 @@
+Debugging
+=========
+
+Redirecting the Gecko output
+----------------------------
+
+The most common way to debug Marionette, as well as chrome code in
+general, is to use `dump()` to print a string to stdout.  In Firefox,
+this log output normally ends up in the gecko.log file in your current
+working directory.  With Fennec it can be inspected using `adb logcat`.
+
+`mach marionette test` takes a `--gecko-log` option which lets
+you redirect this output stream.  This is convenient if you want to
+“merge” the test harness output with the stdout from the browser.
+Per Unix conventions you can use `-` (dash) to have Firefox write
+its log to stdout instead of file:
+
+	% ./mach marionette test --gecko-log -
+
+This debugging technique can be particularly effective when combined
+with using [pdb] in the Python client or the JS remote debugger
+that is described below.
+
+[pdb]: https://docs.python.org/2/library/pdb.html
+
+
+JavaScript debugger
+-------------------
+
+You can attach a JavaScript debugger to the Marionette server
+through the [Browser Toolbox].  This enables you to introspect and
+set breakpoints in Gecko chrome code, which is a far more powerful
+debuggin technique than using `dump()` or `console.log()`.
+
+The browser toolbox can be opened automatically when running Mn
+tests by passing `--jsdebugger` to the mach command:
+
+	% ./mach marionette test --jsdebugger
+
+It will prompt you when to start the test run to allow you time to
+set your breakpoints.  It will also prompt you between each test.
+
+For reference, below is the list of preferences that enables the
+chrome debugger for Marionette.  These are all set implicitly when
+`--jsdebugger` is passed to mach.  In non-official builds, which
+are the default when built using `./mach build`, you will find that
+the chrome debugger won’t prompt for connection and will allow
+remote connections.
+
+  * `devtools.debugger.prompt-connection` → true
+
+    Controls the remote connection prompt.  Note that this will
+    automatically expose your Firefox instance to the network.
+
+  * `devtools.chrome.enabled` → true
+
+    Enables debugging of chrome code.
+
+  * `devtools.debugger.remote-enabled` → true
+
+    Allows a remote debugger to connect, which is necessary for
+    debugging chrome code.
+
+[Browser Toolbox]: https://developer.mozilla.org/en-US/docs/Tools/Browser_Toolbox
diff --git a/testing/marionette/doc/Intro.md b/testing/marionette/doc/Intro.md
new file mode 100644
index 000000000000..1185a01f1432
--- /dev/null
+++ b/testing/marionette/doc/Intro.md
@@ -0,0 +1,83 @@
+Introduction to Marionette
+==========================
+
+Marionette is an automation driver for Mozilla's Gecko engine.
+It can remotely control either the UI or the internal JavaScript of
+a Gecko platform, such as Firefox.  It can control both the chrome
+(i.e. menus and functions) or the content (the webpage loaded inside
+the browsing context), giving a high level of control and ability
+to replicate user actions. In addition to performing actions on the
+browser, Marionette can also read the properties and attributes of
+the DOM.
+
+If this sounds similar to [Selenium/WebDriver] then you're
+correct! Marionette shares much of the same ethos and API as
+Selenium/WebDriver, with additional commands to interact with
+Gecko's chrome interface.  Its goal is to replicate what Selenium
+does for web content: to enable the tester to have the ability to
+send commands to remotely control a user agent.
+
+[Selenium/WebDriver]: https://dvcs.w3.org/hg/webdriver/raw-file/tip/webdriver-spec.html
+
+
+How does it work?
+=================
+
+Marionette consists of two parts: a server which takes requests and
+executes them in Gecko, and a client.  The client sends commands to
+the server and the server executes the command inside the browser.
+
+
+When would I use it?
+====================
+
+If you want to perform UI tests with browser chrome or content,
+Marionette is the tool you're looking for!  You can use it to
+control either web content, or Firefox itself.
+
+A test engineer would typically import the Marionette client package
+into their test framework, import the classes and use the class
+functions and methods to control the browser.  After controlling
+the browser, Marionette can be used to return information about
+the state of the browser which can then be used to validate that
+the action was performed correctly.
+
+
+Using Marionette
+================
+
+Marionette combines a gecko component (the Marionette server) with an
+outside component (the Marionette client), which drives the tests.
+The Marionette server ships with Firefox, and to use it you will
+need to download a Marionette client or use the in-tree client.
+
+  * [Download and setup the Python client for Marionette][2]
+  * [Run Tests with Python][3] – How to run tests using the
+    Python client
+  * You might want to experiment with [using Marionette interactively
+    at a Python command prompt][3]
+  * Start [writing and running][4] tests
+  * Tips on [debugging][5] Marionette code
+  * [Get a Build][6] – Instructions on how to get a Marionette-enabled
+    build of Firefox
+  * [Download and setup the Marionette JS client][7]
+  * [Protocol definition][8]
+
+[1] https://developer.mozilla.org/en-US/docs/Mozilla/QA/Marionette/WebDriver
+[2] http://marionette-client.readthedocs.io/en/latest/
+[3] http://marionette-client.readthedocs.io/en/latest/interactive.html
+[4] ./PythonTests.md
+[5] ./Debugging.md
+[6] https://developer.mozilla.org/en-US/docs/Marionette/Builds
+[7] https://github.com/mozilla-b2g/marionette_js_client
+[8] ./Protocol.md
+
+
+Bugs
+====
+
+Please file any bugs you may find in the `Testing :: Marionette`
+component in Bugzilla.  You can view a [list of current bugs]
+to see if your problem is already being addressed.
+
+[list of current bugs]: https://bugzilla.mozilla.org/buglist.cgi?product=Testing&component=Marionette&resolution=---&list_id=1844713
diff --git a/testing/marionette/doc/Protocol.md b/testing/marionette/doc/Protocol.md
new file mode 100644
index 000000000000..3d52ac97e475
--- /dev/null
+++ b/testing/marionette/doc/Protocol.md
@@ -0,0 +1,110 @@
+Protocol
+========
+
+Marionette provides an asynchronous, parallel pipelining user-facing
+interface.  Message sequencing limits chances of payload race
+conditions and provides a uniform way in which payloads are serialised.
+
+Clients that deliver a blocking WebDriver interface are still
+expected to not send further command requests before the response
+from the last command has come back, but if they still happen to do
+so because of programming error, no harm will be done.  This guards
+against [mixing up responses].
+
+Schematic flow of messages:
+
+	               client      server
+	                 |            |
+	      msgid=1    |----------->|
+	                 |  command   |
+	                 |            |
+	      msgid=2    |<-----------|
+	                 |  command   |
+	                 |            |
+	      msgid=2    |----------->|
+	                 |  response  |
+	                 |            |
+	      msgid=1    |<-----------|
+	                 |  response  |
+	                 |            |
+
+The protocol consists of a [command] message and the corresponding
+[response] message.  A [response] message must always be sent in
+reply to a [commmand] message.
+
+This means that the server implementation does not need to send
+the reply precisely in the order of the received commands: if it
+receives multiple messages, the server may even reply in random order.
+It is therefore strongly adviced that clients take this into account
+when imlpementing the client end of this wire protocol.
+
+This is required for pipelining messages.  On the server side,
+some functions are fast, and some less so.  If the server must
+reply in order, the slow functions delay the other replies even if
+its execution is already completed.
+
+[mixing up responses]: https://bugzil.la/1207125
+
+
+Command
+-------
+
+The request, or command message, is a four element JSON Array as shown
+below, that may originate from either the client- or server remote ends:
+
+	[type, message ID, command, parameters]
+
+  * _type_ must be 0 (integer).  This indicates that the message
+    is a [command].
+
+  * _message ID_ is a 32-bit unsigned integer.  This number is
+    used as a sequencing number that uniquely identifies a pair of
+    [command] and [response] messages.  The other remote part will
+    reply with a corresponding [response] with the same message ID.
+
+  * _command_ is a string identifying the RPC method or command
+    to execute.
+
+  * _parameters_ is an arbitrary JSON serialisable object.
+
+
+Response
+--------
+
+The response message is also a four element array as shown below,
+and must always be sent after receiving a [command]:
+
+	[type, message ID, error, result]
+
+  * _type_ must be 1 (integer).  This indicates that the message is a
+    [response].
+
+  * _message ID_ is a 32-bit unsigned integer.  This corresponds
+    to the [command]’s message ID.
+
+  * _error_ is null if the command executed correctly.  If the
+    error occurred on the server-side, then this is an [error] object.
+
+  * _result_ is the result object from executing the [command], iff
+    it executed correctly.  If an error occurred on the server-side,
+    this field is null.
+
+The structure of the result field can vary, but is documented
+individually for each command.
+
+
+Error object
+------------
+
+An error object is a serialisation of JavaScript error types,
+and it is structured like this:
+
+	{
+		"error": "invalid session id",
+		"message": "No active session with ID 1234",
+		"stacktrace": ""
+	}
+
+All the fields of the error object are required, so the stacktrace and
+message fields may be empty strings.  The error field is guaranteed
+to be one of the JSON error codes as laid out by the [WebDriver standard].
diff --git a/testing/marionette/doc/PythonTests.md b/testing/marionette/doc/PythonTests.md
new file mode 100644
index 000000000000..9c6b8dbc9407
--- /dev/null
+++ b/testing/marionette/doc/PythonTests.md
@@ -0,0 +1,73 @@
+Mn Python tests
+===============
+
+_Marionette_ is the codename of a [remote protocol] built in to
+Firefox as well as the name of a functional test framework for
+automating user interface tests.
+
+The in-tree test framework supports tests written in Python, using
+Python’s [unittest] library.  Test cases are written as a subclass
+of [`MarionetteTestCase`], with child tests belonging to instance
+methods that have a name starting with `test_`.
+
+You can additionally define [`setUp`] and [`tearDown`] instance
+methods to execute code before and after child tests, and
+[`setUpClass`]/[`tearDownClass`] for the parent test.  When you use
+these, it is important to remember calling the [`MarionetteTestCase`]
+superclass’ own `setUp`/`tearDown` methods since they handle
+setup/cleanup of the session.
+
+The test structure is illustrated here:
+
+	from marionette_test import MarionetteTestCase
+
+	class TestSomething(MarionetteTestCase):
+	    def setUp(self):
+	        # code to execute before any tests are run
+	        MarionetteTestCase.setUp(self)
+
+	    def test_foo(self):
+	        # run test for 'foo'
+
+	    def test_bar(self):
+	        # run test for 'bar'
+
+	    def tearDown(self):
+	        # code to execute after all tests are run
+	        MarionetteTestCase.tearDown(self)
+
+[remote protocol]: https://developer.mozilla.org/en-US/docs/Mozilla/QA/Marionette/Protocol
+[unittest]: https://docs.python.org/2.7/library/unittest.html
+[`MarionetteTestCase`]: https://developer.mozilla.org/en-US/docs/Mozilla/QA/Marionette/MarionetteTestCase
+[`setUp`]: https://docs.python.org/2.7/library/unittest.html#unittest.TestCase.setUp
+[`setUpClass`]: https://docs.python.org/2.7/library/unittest.html#unittest.TestCase.setUpClass
+[`tearDown`]: https://docs.python.org/2.7/library/unittest.html#unittest.TestCase.tearDown
+[`tearDownClass`]: https://docs.python.org/2.7/library/unittest.html#unittest.TestCase.tearDownClass
+
+
+Test assertions
+---------------
+
+Assertions are provided courtesy of [unittest].  For example:
+
+	from marionette_test import MarionetteTestCase
+
+	class TestSomething(MarionetteTestCase):
+	    def test_foo(self):
+	        self.assertEqual(9, 3 * 3, '3 x 3 should be 9')
+	        self.assertTrue(type(2) == int, '2 should be an integer')
+
+
+The API
+-------
+
+The full API documentation is found at
+http://marionette-client.readthedocs.io/en/master/, but the key
+objects are:
+
+  * [`MarionetteTestCase`]: a subclass for `unittest.TestCase`
+    used as a base class for all tests to run.
+
+  * [`Marionette`]: client that speaks to Firefox.
+
+[`Marionette`]: http://marionette-client.readthedocs.io/en/master/reference.html#marionette
diff --git a/testing/marionette/element.js b/testing/marionette/element.js
index 07e41d5b4864..58366937781f 100644
--- a/testing/marionette/element.js
+++ b/testing/marionette/element.js
@@ -397,20 +397,39 @@ element.findByXPathAll = function(root, startNode, expr) {
 };
 
 /**
- * Find all hyperlinks dscendant of |node| which link text is |s|.
+ * Find all hyperlinks descendant of <var>node</var> which link text
+ * is <var>s</var>.
  *
  * @param {DOMElement} node
- *     Where in the DOM hierarchy to being searching.
+ *     Where in the DOM hierarchy to begin searching.
  * @param {string} s
  *     Link text to search for.
  *
  * @return {Array.<DOMAnchorElement>}
- *     Sequence of link elements which text is |s|.
+ *     Sequence of link elements which text is <var>s</var>.
  */
 element.findByLinkText = function(node, s) {
   return filterLinks(node, link => link.text.trim() === s);
 };
 
+/**
+ * Find anonymous nodes of <var>node</var>.
+ *
+ * @param {XULElement} rootNode
+ *     Root node of the document.
+ * @param {XULElement} node
+ *     Where in the DOM hierarchy to begin searching.
+ *
+ * @return {Iterable.<XULElement>}
+ *     Iterator over anonymous elements.
+ */
+element.findAnonymousNodes = function* (rootNode, node) {
+  let anons = rootNode.getAnonymousNodes(node) || [];
+  for (let node of anons) {
+    yield node;
+  }
+};
+
 /**
  * Find all hyperlinks descendant of |node| which link text contains |s|.
  *
@@ -523,7 +542,7 @@ function findElement(using, value, rootNode, startNode) {
       }
 
     case element.Strategy.Anon:
-      return rootNode.getAnonymousNodes(startNode);
+      return element.findAnonymousNodes(rootNode, startNode).next().value;
 
     case element.Strategy.AnonAttribute:
       let attr = Object.keys(value)[0];
@@ -586,7 +605,7 @@ function findElements(using, value, rootNode, startNode) {
       return startNode.querySelectorAll(value);
 
     case element.Strategy.Anon:
-      return rootNode.getAnonymousNodes(startNode);
+      return [...element.findAnonymousNodes(rootNode, startNode)];
 
     case element.Strategy.AnonAttribute:
       let attr = Object.keys(value)[0];
@@ -602,7 +621,15 @@ function findElements(using, value, rootNode, startNode) {
   }
 }
 
-/** Determines if |obj| is an HTML or JS collection. */
+/**
+ * Determines if <var>obj<var> is an HTML or JS collection.
+ *
+ * @param {*} seq
+ *     Type to determine.
+ *
+ * @return {boolean}
+ *     True if <var>seq</va> is collection.
+ */
 element.isCollection = function(seq) {
   switch (Object.prototype.toString.call(seq)) {
     case "[object Arguments]":
@@ -804,9 +831,10 @@ element.inViewport = function(el, x = undefined, y = undefined) {
  * Gets the element's container element.
  *
  * An element container is defined by the WebDriver
- * specification to be an <option> element in a valid element context
- * (https://html.spec.whatwg.org/#concept-element-contexts), meaning
- * that it has an ancestral element that is either <datalist> or <select>.
+ * specification to be an <tt>&lt;option&gt;</tt> element in a
+ * <a href="https://html.spec.whatwg.org/#concept-element-contexts">valid
+ * element context</a>, meaning that it has an ancestral element
+ * that is either <tt>&lt;datalist&gt;</tt> or <tt>&lt;select&gt;</tt>.
  *
  * If the element does not have a valid context, its container element
  * is itself.
@@ -845,19 +873,20 @@ element.getContainer = function(el) {
  *
  * This means an element is considered to be in view, but not necessarily
  * pointer-interactable, if it is found somewhere in the
- * |elementsFromPoint| list at |el|'s in-view centre coordinates.
+ * <code>elementsFromPoint</code> list at <var>el</var>'s in-view
+ * centre coordinates.
  *
- * Before running the check, we change |el|'s pointerEvents style property
- * to "auto", since elements without pointer events enabled do not turn
- * up in the paint tree we get from document.elementsFromPoint.  This is
- * a specialisation that is only relevant when checking if the element is
- * in view.
+ * Before running the check, we change <var>el</var>'s pointerEvents
+ * style property to "auto", since elements without pointer events
+ * enabled do not turn up in the paint tree we get from
+ * document.elementsFromPoint.  This is a specialisation that is only
+ * relevant when checking if the element is in view.
  *
  * @param {Element} el
  *     Element to check if is in view.
  *
  * @return {boolean}
- *     True if |el| is inside the viewport, or false otherwise.
+ *     True if <var>el</var> is inside the viewport, or false otherwise.
  */
 element.isInView = function(el) {
   let originalPointerEvents = el.style.pointerEvents;
@@ -1060,7 +1089,7 @@ const boolEls = {
  * Tests if the attribute is a boolean attribute on element.
  *
  * @param {DOMElement} el
- *     Element to test if |attr| is a boolean attribute on.
+ *     Element to test if <var>attr</var> is a boolean attribute on.
  * @param {string} attr
  *     Attribute to test is a boolean attribute.
  *
diff --git a/testing/marionette/harness/marionette_harness/tests/unit/test_marionette.py b/testing/marionette/harness/marionette_harness/tests/unit/test_marionette.py
index e68312872e20..da2ed5bd2c2b 100644
--- a/testing/marionette/harness/marionette_harness/tests/unit/test_marionette.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_marionette.py
@@ -31,37 +31,3 @@ class TestMarionette(MarionetteTestCase):
         start_time = time.time()
         self.assertFalse(self.marionette.wait_for_port(timeout=5))
         self.assertLess(time.time() - start_time, 5)
-
-
-class TestProtocol2Errors(MarionetteTestCase):
-    def setUp(self):
-        MarionetteTestCase.setUp(self)
-        self.op = self.marionette.protocol
-        self.marionette.protocol = 2
-
-    def tearDown(self):
-        self.marionette.protocol = self.op
-        MarionetteTestCase.tearDown(self)
-
-    def test_malformed_packet(self):
-        req = ["error", "message", "stacktrace"]
-        ps = []
-        for p in [p for i in range(0, len(req) + 1) for p in itertools.permutations(req, i)]:
-            ps.append(dict((x, None) for x in p))
-
-        for p in filter(lambda p: len(p) < 3, ps):
-            self.assertRaises(KeyError, self.marionette._handle_error, p)
-
-    def test_known_error_status(self):
-        with self.assertRaises(errors.NoSuchElementException):
-            self.marionette._handle_error(
-                {"error": errors.NoSuchElementException.status,
-                 "message": None,
-                 "stacktrace": None})
-
-    def test_unknown_error_status(self):
-        with self.assertRaises(errors.MarionetteException):
-            self.marionette._handle_error(
-                {"error": "barbera",
-                 "message": None,
-                 "stacktrace": None})
diff --git a/testing/marionette/harness/marionette_harness/tests/unit/test_transport.py b/testing/marionette/harness/marionette_harness/tests/unit/test_transport.py
index 39e36a9b224c..e1891ebb4825 100644
--- a/testing/marionette/harness/marionette_harness/tests/unit/test_transport.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_transport.py
@@ -11,7 +11,7 @@ from marionette_driver.transport import (
     Response,
 )
 
-from marionette_harness import MarionetteTestCase, skip_unless_protocol
+from marionette_harness import MarionetteTestCase
 
 
 get_current_url = ("getCurrentUrl", None)
@@ -33,19 +33,6 @@ class TestMessageSequencing(MarionetteTestCase):
         self.marionette.client.send(cmd)
         return self.last_id
 
-    @skip_unless_protocol("Skip for level < 3", lambda level: level >= 3)
-    def test_discard_older_messages(self):
-        first = self.send(*get_current_url)
-        second = self.send(*execute_script)
-        resp = self.marionette.client.receive()
-        self.assertEqual(second, resp.id)
-
-    @skip_unless_protocol("Skip for level < 3", lambda level: level >= 3)
-    def test_last_id_incremented(self):
-        before = self.last_id
-        self.send(*get_current_url)
-        self.assertGreater(self.last_id, before)
-
 
 class MessageTestCase(MarionetteTestCase):
     def assert_attr(self, obj, attr):
diff --git a/testing/marionette/legacyaction.js b/testing/marionette/legacyaction.js
index e2304922d4e4..e21cd4c64755 100644
--- a/testing/marionette/legacyaction.js
+++ b/testing/marionette/legacyaction.js
@@ -81,7 +81,7 @@ action.Chain.prototype.dispatchActions = function (
 
   return new Promise(resolve => {
     this.actions(commandArray, touchId, 0, keyModifiers, resolve);
-  }).catch(this.resetValues);
+  }).catch(this.resetValues.bind(this));
 };
 
 /**
diff --git a/testing/web-platform/meta/2dcontext/fill-and-stroke-styles/2d.gradient.object.current.html.ini b/testing/web-platform/meta/2dcontext/fill-and-stroke-styles/2d.gradient.object.current.html.ini
index c849f911b7fc..ea132f67f4c8 100644
--- a/testing/web-platform/meta/2dcontext/fill-and-stroke-styles/2d.gradient.object.current.html.ini
+++ b/testing/web-platform/meta/2dcontext/fill-and-stroke-styles/2d.gradient.object.current.html.ini
@@ -1,5 +1,6 @@
 [2d.gradient.object.current.html]
   type: testharness
   [Canvas test: 2d.gradient.object.current]
-    expected: FAIL
+    expected:
+      if not stylo: FAIL
 
diff --git a/third_party/rust/pdqsort/.cargo-checksum.json b/third_party/rust/pdqsort/.cargo-checksum.json
deleted file mode 100644
index e58107dbfd43..000000000000
--- a/third_party/rust/pdqsort/.cargo-checksum.json
+++ /dev/null
@@ -1 +0,0 @@
-{"files":{".cargo-ok":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",".travis.yml":"85e71e3082a4d00de52505b07957cca71718d9a1cc531f66d77ad8f54dd190a2","Cargo.toml":"72b56d640b72470dedf71dead0d4ceda51ec82ac048dea9a97ab6be440eb41a9","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"0621878e61f0d0fda054bcbe02df75192c28bde1ecc8289cbd86aeba2dd72720","README.md":"795851777c3d915da30f2b11b21f478fb46f793170321b1ffa64b6eb27d93127","benches/bench.rs":"4e5e084d25ce4fe5824e653438249206278f3f428c4c2bfb96f98ad8622dfa5e","src/lib.rs":"c3a7cff009a399f1d180b23daaf483798021a117a352c81704dd8ff470ba9f16"},"package":"ceca1642c89148ca05611cc775a0c383abef355fc4907c4e95f49f7b09d6287c"}
\ No newline at end of file
diff --git a/third_party/rust/pdqsort/.cargo-ok b/third_party/rust/pdqsort/.cargo-ok
deleted file mode 100644
index e69de29bb2d1..000000000000
diff --git a/third_party/rust/pdqsort/.travis.yml b/third_party/rust/pdqsort/.travis.yml
deleted file mode 100644
index 66eed7b8ef54..000000000000
--- a/third_party/rust/pdqsort/.travis.yml
+++ /dev/null
@@ -1,6 +0,0 @@
-language: rust
-
-rust:
-  - stable
-  - beta
-  - nightly
diff --git a/third_party/rust/pdqsort/Cargo.toml b/third_party/rust/pdqsort/Cargo.toml
deleted file mode 100644
index e76fee66e22f..000000000000
--- a/third_party/rust/pdqsort/Cargo.toml
+++ /dev/null
@@ -1,21 +0,0 @@
-[package]
-name = "pdqsort"
-version = "0.1.2"
-authors = ["Stjepan Glavina <stjepang@gmail.com>"]
-description = "Pattern-defeating quicksort"
-repository = "https://github.com/stjepang/pdqsort"
-documentation = "https://docs.rs/pdqsort"
-readme = "README.md"
-license = "Apache-2.0/MIT"
-keywords = ["sort", "sorting", "no_std", "quicksort", "introsort"]
-categories = ["algorithms"]
-exclude = [
-    "out*",
-    "src/bin/test.rs",
-]
-
-[badges]
-travis-ci = { repository = "stjepang/pdqsort" }
-
-[dev-dependencies]
-rand = "0.3"
diff --git a/third_party/rust/pdqsort/LICENSE-APACHE b/third_party/rust/pdqsort/LICENSE-APACHE
deleted file mode 100644
index 16fe87b06e80..000000000000
--- a/third_party/rust/pdqsort/LICENSE-APACHE
+++ /dev/null
@@ -1,201 +0,0 @@
-                              Apache License
-                        Version 2.0, January 2004
-                     http://www.apache.org/licenses/
-
-TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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-	http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
diff --git a/third_party/rust/pdqsort/LICENSE-MIT b/third_party/rust/pdqsort/LICENSE-MIT
deleted file mode 100644
index 25597d5838fa..000000000000
--- a/third_party/rust/pdqsort/LICENSE-MIT
+++ /dev/null
@@ -1,25 +0,0 @@
-Copyright (c) 2010 The Rust Project Developers
-
-Permission is hereby granted, free of charge, to any
-person obtaining a copy of this software and associated
-documentation files (the "Software"), to deal in the
-Software without restriction, including without
-limitation the rights to use, copy, modify, merge,
-publish, distribute, sublicense, and/or sell copies of
-the Software, and to permit persons to whom the Software
-is furnished to do so, subject to the following
-conditions:
-
-The above copyright notice and this permission notice
-shall be included in all copies or substantial portions
-of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
-ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
-TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
-PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
-SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
-CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
-OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
-IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-DEALINGS IN THE SOFTWARE.
diff --git a/third_party/rust/pdqsort/README.md b/third_party/rust/pdqsort/README.md
deleted file mode 100644
index c36b591db7d3..000000000000
--- a/third_party/rust/pdqsort/README.md
+++ /dev/null
@@ -1,81 +0,0 @@
-# Pattern-defeating quicksort
-
-[![Build Status](https://travis-ci.org/stjepang/pdqsort.svg?branch=master)](https://travis-ci.org/stjepang/pdqsort)
-[![License](https://img.shields.io/badge/license-Apache--2.0%2FMIT-blue.svg)](https://github.com/stjepang/pdqsort)
-[![Cargo](https://img.shields.io/crates/v/pdqsort.svg)](https://crates.io/crates/pdqsort)
-[![Documentation](https://docs.rs/pdqsort/badge.svg)](https://docs.rs/pdqsort)
-
-This sort is significantly faster than the standard sort in Rust. In particular, it sorts
-random arrays of integers approximately 45% faster. The key drawback is that it is an unstable
-sort (i.e. may reorder equal elements). However, in most cases stability doesn't matter anyway.
-
-The algorithm is based on pdqsort by Orson Peters, published at: https://github.com/orlp/pdqsort
-
-#### Properties
-
-* Best-case running time is `O(n)`.
-* Worst-case running time is `O(n log n)`.
-* Unstable, i.e. may reorder equal elements.
-* Does not allocate additional memory.
-* Uses `#![no_std]`.
-
-#### Examples
-
-```rust
-extern crate pdqsort;
-
-let mut v = [-5i32, 4, 1, -3, 2];
-
-pdqsort::sort(&mut v);
-assert!(v == [-5, -3, 1, 2, 4]);
-
-pdqsort::sort_by(&mut v, |a, b| b.cmp(a));
-assert!(v == [4, 2, 1, -3, -5]);
-
-pdqsort::sort_by_key(&mut v, |k| k.abs());
-assert!(v == [1, 2, -3, 4, -5]);
-```
-
-#### A simple benchmark
-
-Sorting 10 million random numbers of type `u64`:
-
-| Sort              | Time       |
-|-------------------|-----------:|
-| pdqsort           | **370 ms** |
-| slice::sort       |     668 ms |
-| [quickersort][qs] |     777 ms |
-| [dmsort][ds]      |     728 ms |
-| [rdxsort][rs]     |     602 ms |
-
-#### Extensive benchmarks
-
-The following benchmarks are [used in Rust][bench] for testing the performance of slice::sort.
-
-*Note: The numbers for dmsort are outdated.*
-
-| Benchmark               | pdqsort       | slice::sort   | [quickersort][qs] | ~~[dmsort][ds]~~ | [rdxsort][rs] |
-|-------------------------|--------------:|--------------:|------------------:|-------------:|--------------:|
-| large_ascending         |         11 us |      **9 us** |             12 us |        22 us |        358 us |
-| large_descending        |     **14 us** |     **14 us** |             46 us |       144 us |        347 us |
-| large_random            |    **342 us** |        509 us |            534 us |       544 us |        399 us |
-| large_random_expensive  |         63 ms |     **24 ms** |                -  |        31 ms |            -  |
-| large_mostly_ascending  |         82 us |        239 us |            129 us |    **45 us** |        353 us |
-| large_mostly_descending |     **93 us** |        267 us |            135 us |       282 us |        349 us |
-| large_big_ascending     |        375 us |    **370 us** |            374 us |       412 us |     49,597 us |
-| large_big_descending    |    **441 us** |    **441 us** |            571 us |       814 us |     49,675 us |
-| large_big_random        |  **1,573 us** |      2,141 us |          1,971 us |     2,308 us |     43,578 us |
-| medium_ascending        |        186 ns |        145 ns |        **148 ns** |       259 ns |      4,509 ns |
-| medium_descending       |        214 ns |    **188 ns** |            490 ns |     1,344 ns |      4,947 ns |
-| medium_random           |  **2,926 ns** |      3,297 ns |          3,252 ns |     3,722 ns |      6,466 ns |
-| small_ascending         |         32 ns |         32 ns |         **25 ns** |        47 ns |      1,597 ns |
-| small_descending        |         55 ns |         55 ns |         **51 ns** |       232 ns |      1,595 ns |
-| small_random            |        347 ns |        346 ns |        **333 ns** |       484 ns |      3,841 ns |
-| small_big_ascending     |         92 ns |         92 ns |         **89 ns** |       136 ns |     35,749 ns |
-| small_big_descending    |    **246 ns** |    **246 ns** |            420 ns |       517 ns |     35,807 ns |
-| small_big_random        |    **492 ns** |    **492 ns** |            582 ns |       671 ns |     46,393 ns |
-
-[qs]: https://github.com/notriddle/quickersort
-[ds]: https://github.com/emilk/drop-merge-sort
-[rs]: https://github.com/crepererum/rdxsort-rs
-[bench]: https://github.com/rust-lang/rust/blob/468227129d08b52c4cf90313b29fdad1b80e596b/src/libcollectionstest/slice.rs#L1406
diff --git a/third_party/rust/pdqsort/benches/bench.rs b/third_party/rust/pdqsort/benches/bench.rs
deleted file mode 100755
index 6dd034db05a7..000000000000
--- a/third_party/rust/pdqsort/benches/bench.rs
+++ /dev/null
@@ -1,107 +0,0 @@
-#![feature(test)]
-
-extern crate pdqsort;
-extern crate rand;
-extern crate test;
-
-use rand::{Rng, thread_rng};
-use std::mem;
-use test::Bencher;
-
-fn gen_ascending(len: usize) -> Vec<u64> {
-    (0..len as u64).collect()
-}
-
-fn gen_descending(len: usize) -> Vec<u64> {
-    (0..len as u64).rev().collect()
-}
-
-fn gen_random(len: usize) -> Vec<u64> {
-    let mut rng = thread_rng();
-    rng.gen_iter::<u64>().take(len).collect()
-}
-
-fn gen_mostly_ascending(len: usize) -> Vec<u64> {
-    let mut rng = thread_rng();
-    let mut v = gen_ascending(len);
-    for _ in (0usize..).take_while(|x| x * x <= len) {
-        let x = rng.gen::<usize>() % len;
-        let y = rng.gen::<usize>() % len;
-        v.swap(x, y);
-    }
-    v
-}
-
-fn gen_mostly_descending(len: usize) -> Vec<u64> {
-    let mut rng = thread_rng();
-    let mut v = gen_descending(len);
-    for _ in (0usize..).take_while(|x| x * x <= len) {
-        let x = rng.gen::<usize>() % len;
-        let y = rng.gen::<usize>() % len;
-        v.swap(x, y);
-    }
-    v
-}
-
-fn gen_big_random(len: usize) -> Vec<[u64; 16]> {
-    let mut rng = thread_rng();
-    rng.gen_iter().map(|x| [x; 16]).take(len).collect()
-}
-
-fn gen_big_ascending(len: usize) -> Vec<[u64; 16]> {
-    (0..len as u64).map(|x| [x; 16]).take(len).collect()
-}
-
-fn gen_big_descending(len: usize) -> Vec<[u64; 16]> {
-    (0..len as u64).rev().map(|x| [x; 16]).take(len).collect()
-}
-
-macro_rules! sort_bench {
-    ($name:ident, $gen:expr, $len:expr) => {
-        #[bench]
-        fn $name(b: &mut Bencher) {
-            b.iter(|| pdqsort::sort(&mut $gen($len)));
-            b.bytes = $len * mem::size_of_val(&$gen(1)[0]) as u64;
-        }
-    }
-}
-
-sort_bench!(sort_small_random, gen_random, 10);
-sort_bench!(sort_small_ascending, gen_ascending, 10);
-sort_bench!(sort_small_descending, gen_descending, 10);
-
-sort_bench!(sort_small_big_random, gen_big_random, 10);
-sort_bench!(sort_small_big_ascending, gen_big_ascending, 10);
-sort_bench!(sort_small_big_descending, gen_big_descending, 10);
-
-sort_bench!(sort_medium_random, gen_random, 100);
-sort_bench!(sort_medium_ascending, gen_ascending, 100);
-sort_bench!(sort_medium_descending, gen_descending, 100);
-
-sort_bench!(sort_large_random, gen_random, 10000);
-sort_bench!(sort_large_ascending, gen_ascending, 10000);
-sort_bench!(sort_large_descending, gen_descending, 10000);
-sort_bench!(sort_large_mostly_ascending, gen_mostly_ascending, 10000);
-sort_bench!(sort_large_mostly_descending, gen_mostly_descending, 10000);
-
-sort_bench!(sort_large_big_random, gen_big_random, 10000);
-sort_bench!(sort_large_big_ascending, gen_big_ascending, 10000);
-sort_bench!(sort_large_big_descending, gen_big_descending, 10000);
-
-#[bench]
-fn sort_large_random_expensive(b: &mut Bencher) {
-    let len = 10000;
-    b.iter(|| {
-        let mut v = gen_random(len);
-        let mut count = 0;
-        pdqsort::sort_by(&mut v, |a: &u64, b: &u64| {
-            count += 1;
-            if count % 1_000_000_000 == 0 {
-                panic!("should not happen");
-            }
-            (*a as f64).cos().partial_cmp(&(*b as f64).cos()).unwrap()
-        });
-        test::black_box(count);
-    });
-    b.bytes = len as u64 * mem::size_of::<u64>() as u64;
-}
diff --git a/third_party/rust/pdqsort/src/lib.rs b/third_party/rust/pdqsort/src/lib.rs
deleted file mode 100644
index be652b8ebf51..000000000000
--- a/third_party/rust/pdqsort/src/lib.rs
+++ /dev/null
@@ -1,736 +0,0 @@
-//! Pattern-defeating quicksort.
-//!
-//! This sort is significantly faster than the standard sort in Rust. In particular, it sorts
-//! random arrays of integers approximately 45% faster. The key drawback is that it is an unstable
-//! sort (i.e. may reorder equal elements). However, in most cases stability doesn't matter anyway.
-//!
-//! The algorithm is based on pdqsort by Orson Peters, published at: https://github.com/orlp/pdqsort
-//!
-//! # Properties
-//!
-//! - Best-case running time is `O(n)`.
-//! - Worst-case running time is `O(n log n)`.
-//! - Unstable, i.e. may reorder equal elements.
-//! - Does not allocate additional memory.
-//! - Uses `#![no_std]`.
-//!
-//! # Examples
-//!
-//! ```
-//! extern crate pdqsort;
-//!
-//! let mut v = [-5i32, 4, 1, -3, 2];
-//!
-//! pdqsort::sort(&mut v);
-//! assert!(v == [-5, -3, 1, 2, 4]);
-//!
-//! pdqsort::sort_by(&mut v, |a, b| b.cmp(a));
-//! assert!(v == [4, 2, 1, -3, -5]);
-//!
-//! pdqsort::sort_by_key(&mut v, |k| k.abs());
-//! assert!(v == [1, 2, -3, 4, -5]);
-//! ```
-
-#![no_std]
-
-use core::cmp::{self, Ordering};
-use core::mem;
-use core::ptr;
-
-/// When dropped, takes the value out of `Option` and writes it into `dest`.
-///
-/// This allows us to safely read the pivot into a stack-allocated variable for efficiency, and
-/// write it back into the slice after partitioning. This way we ensure that the write happens
-/// even if `is_less` panics in the meantime.
-struct WriteOnDrop<T> {
-    value: Option<T>,
-    dest: *mut T,
-}
-
-impl<T> Drop for WriteOnDrop<T> {
-    fn drop(&mut self) {
-        unsafe {
-            ptr::write(self.dest, self.value.take().unwrap());
-        }
-    }
-}
-
-/// Sorts a slice using insertion sort, which is `O(n^2)` worst-case.
-fn insertion_sort<T, F>(v: &mut [T], is_less: &mut F)
-    where F: FnMut(&T, &T) -> bool
-{
-    let len = v.len();
-
-    for i in 1..len {
-        unsafe {
-            if is_less(v.get_unchecked(i), v.get_unchecked(i - 1)) {
-                // There are three ways to implement insertion here:
-                //
-                // 1. Swap adjacent elements until the first one gets to its final destination.
-                //    However, this way we copy data around more than is necessary. If elements are
-                //    big structures (costly to copy), this method will be slow.
-                //
-                // 2. Iterate until the right place for the first element is found. Then shift the
-                //    elements succeeding it to make room for it and finally place it into the
-                //    remaining hole. This is a good method.
-                //
-                // 3. Copy the first element into a temporary variable. Iterate until the right
-                //    place for it is found. As we go along, copy every traversed element into the
-                //    slot preceding it. Finally, copy data from the temporary variable into the
-                //    remaining hole. This method is very good. Benchmarks demonstrated slightly
-                //    better performance than with the 2nd method.
-                //
-                // All methods were benchmarked, and the 3rd showed best results. So we chose that
-                // one.
-                let mut tmp = NoDrop { value: Some(ptr::read(v.get_unchecked(i))) };
-
-                // Intermediate state of the insertion process is always tracked by `hole`, which
-                // serves two purposes:
-                // 1. Protects integrity of `v` from panics in `is_less`.
-                // 2. Fills the remaining hole in `v` in the end.
-                //
-                // Panic safety:
-                //
-                // If `is_less` panics at any point during the process, `hole` will get dropped and
-                // fill the hole in `v` with `tmp`, thus ensuring that `v` still holds every object
-                // it initially held exactly once.
-                let mut hole = InsertionHole {
-                    src: tmp.value.as_mut().unwrap(),
-                    dest: v.get_unchecked_mut(i - 1),
-                };
-                ptr::copy_nonoverlapping(v.get_unchecked(i - 1), v.get_unchecked_mut(i), 1);
-
-                for j in (0..i-1).rev() {
-                    if !is_less(&tmp.value.as_ref().unwrap(), v.get_unchecked(j)) {
-                        break;
-                    }
-                    ptr::copy_nonoverlapping(v.get_unchecked(j), v.get_unchecked_mut(j + 1), 1);
-                    hole.dest = v.get_unchecked_mut(j);
-                }
-            }
-            // `hole` gets dropped and thus copies `tmp` into the remaining hole in `v`.
-        }
-    }
-
-    // Holds a value, but never drops it.
-    struct NoDrop<T> {
-        value: Option<T>,
-    }
-
-    impl<T> Drop for NoDrop<T> {
-        fn drop(&mut self) {
-            mem::forget(self.value.take());
-        }
-    }
-
-    // When dropped, copies from `src` into `dest`.
-    struct InsertionHole<T> {
-        src: *mut T,
-        dest: *mut T,
-    }
-
-    impl<T> Drop for InsertionHole<T> {
-        fn drop(&mut self) {
-            unsafe { ptr::copy_nonoverlapping(self.src, self.dest, 1); }
-        }
-    }
-}
-
-/// Sorts `v` using heapsort, which guarantees `O(n log n)` worst-case.
-#[cold]
-fn heapsort<T, F>(v: &mut [T], is_less: &mut F)
-    where F: FnMut(&T, &T) -> bool
-{
-    // This binary heap respects the invariant `parent >= child`.
-    let mut sift_down = |v: &mut [T], mut node| {
-        loop {
-            // Children of `node`:
-            let left = 2 * node + 1;
-            let right = 2 * node + 2;
-
-            // Choose the greater child.
-            let greater = if right < v.len() && is_less(&v[left], &v[right]) {
-                right
-            } else {
-                left
-            };
-
-            // Stop if the invariant holds at `node`.
-            if greater >= v.len() || !is_less(&v[node], &v[greater]) {
-                break;
-            }
-
-            // Swap `node` with the greater child, move one step down, and continue sifting.
-            v.swap(node, greater);
-            node = greater;
-        }
-    };
-
-    // Build the heap in linear time.
-    for i in (0 .. v.len() / 2).rev() {
-        sift_down(v, i);
-    }
-
-    // Pop maximal elements from the heap.
-    for i in (1 .. v.len()).rev() {
-        v.swap(0, i);
-        sift_down(&mut v[..i], 0);
-    }
-}
-
-/// Partitions `v` into elements smaller than `pivot`, followed by elements greater than or equal
-/// to `pivot`. Returns the number of elements smaller than `pivot`.
-///
-/// Partitioning is performed block-by-block in order to minimize the cost of branching operations.
-/// This idea is presented in the [BlockQuicksort][pdf] paper.
-///
-/// [pdf]: http://drops.dagstuhl.de/opus/volltexte/2016/6389/pdf/LIPIcs-ESA-2016-38.pdf
-fn partition_in_blocks<T, F>(v: &mut [T], pivot: &T, is_less: &mut F) -> usize
-    where F: FnMut(&T, &T) -> bool
-{
-    const BLOCK: usize = 128;
-
-    // State on the left side.
-    let mut l = v.as_mut_ptr();
-    let mut block_l = BLOCK;
-    let mut start_l = ptr::null_mut();
-    let mut end_l = ptr::null_mut();
-    let mut offsets_l: [u8; BLOCK] = unsafe { mem::uninitialized() };
-
-    // State on the right side.
-    let mut r = unsafe { l.offset(v.len() as isize) };
-    let mut block_r = BLOCK;
-    let mut start_r = ptr::null_mut();
-    let mut end_r = ptr::null_mut();
-    let mut offsets_r: [u8; BLOCK] = unsafe { mem::uninitialized() };
-
-    // Returns the number of elements between pointers `l` (inclusive) and `r` (exclusive).
-    fn width<T>(l: *mut T, r: *mut T) -> usize {
-        assert!(mem::size_of::<T>() > 0);
-        (r as usize - l as usize) / mem::size_of::<T>()
-    }
-
-    // Roughly speaking, the idea is to repeat the following steps until completion:
-    //
-    // 1. Trace a block from the left side to identify elements greater than or equal to the pivot.
-    // 2. Trace a block from the right side to identify elements less than the pivot.
-    // 3. Exchange the identified elements between the left and right side.
-    loop {
-        // We are done with partitioning block-by-block when `l` and `r` get very close. Then we do
-        // some patch-up work in order to partition the remaining elements in between.
-        let is_done = width(l, r) <= 2 * BLOCK;
-
-        if is_done {
-            // Number of remaining elements (still not compared to the pivot).
-            let rem = width(l, r) - (start_l < end_l || start_r < end_r) as usize * BLOCK;
-
-            // Adjust block sizes so that the left and right block don't overlap, but get perfectly
-            // aligned to cover the whole remaining gap.
-            if start_l < end_l {
-                block_r = rem;
-            } else if start_r < end_r {
-                block_l = rem;
-            } else {
-                block_l = rem / 2;
-                block_r = rem - block_l;
-            }
-            debug_assert!(width(l, r) == block_l + block_r);
-        }
-
-        if start_l == end_l {
-            // Trace `block_l` elements from the left side.
-            start_l = offsets_l.as_mut_ptr();
-            end_l = offsets_l.as_mut_ptr();
-            let mut elem = l;
-
-            for i in 0..block_l {
-                unsafe {
-                    // Branchless comparison.
-                    *end_l = i as u8;
-                    end_l = end_l.offset(!is_less(&*elem, pivot) as isize);
-                    elem = elem.offset(1);
-                }
-            }
-        }
-
-        if start_r == end_r {
-            // Trace `block_r` elements from the right side.
-            start_r = offsets_r.as_mut_ptr();
-            end_r = offsets_r.as_mut_ptr();
-            let mut elem = r;
-
-            for i in 0..block_r {
-                unsafe {
-                    // Branchless comparison.
-                    elem = elem.offset(-1);
-                    *end_r = i as u8;
-                    end_r = end_r.offset(is_less(&*elem, pivot) as isize);
-                }
-            }
-        }
-
-        // Number of out-of-order elements to swap between the left and right side.
-        let count = cmp::min(width(start_l, end_l), width(start_r, end_r));
-
-        if count > 0 {
-            macro_rules! left { () => { l.offset(*start_l as isize) } }
-            macro_rules! right { () => { r.offset(-(*start_r as isize) - 1) } }
-
-            // Instead of swapping one pair at the time, it is more efficient to perform a cyclic
-            // permutation. This is not strictly equivalent to swapping, but produces a similar
-            // result using fewer memory operations.
-            unsafe {
-                let tmp = ptr::read(left!());
-                ptr::copy_nonoverlapping(right!(), left!(), 1);
-
-                for _ in 1..count {
-                    start_l = start_l.offset(1);
-                    ptr::copy_nonoverlapping(left!(), right!(), 1);
-                    start_r = start_r.offset(1);
-                    ptr::copy_nonoverlapping(right!(), left!(), 1);
-                }
-
-                ptr::copy_nonoverlapping(&tmp, right!(), 1);
-                mem::forget(tmp);
-                start_l = start_l.offset(1);
-                start_r = start_r.offset(1);
-            }
-        }
-
-        if start_l == end_l {
-            // The left block is fully exhausted. Shift the left bound forward.
-            l = unsafe { l.offset(block_l as isize) };
-        }
-
-        if start_r == end_r {
-            // The right block is fully exhausted. Shift the right bound backward.
-            r = unsafe { r.offset(-(block_r as isize)) };
-        }
-
-        if is_done {
-            break;
-        }
-    }
-
-    if start_l < end_l {
-        // Move the remaining to-be-swapped elements to the far right.
-        while start_l < end_l {
-            unsafe {
-                end_l = end_l.offset(-1);
-                ptr::swap(l.offset(*end_l as isize), r.offset(-1));
-                r = r.offset(-1);
-            }
-        }
-        width(v.as_mut_ptr(), r)
-    } else {
-        // Move the remaining to-be-swapped elements to the far left.
-        while start_r < end_r {
-            unsafe {
-                end_r = end_r.offset(-1);
-                ptr::swap(l, r.offset(-(*end_r as isize) - 1));
-                l = l.offset(1);
-            }
-        }
-        width(v.as_mut_ptr(), l)
-    }
-}
-
-/// Partitions `v` into elements smaller than `v[pivot]`, followed by elements greater than or
-/// equal to `v[pivot]`.
-///
-/// Returns two things:
-///
-/// 1. Number of elements smaller than `v[pivot]`.
-/// 2. `true` if `v` was already partitioned.
-fn partition<T, F>(v: &mut [T], pivot: usize, is_less: &mut F) -> (usize, bool)
-    where F: FnMut(&T, &T) -> bool
-{
-    v.swap(0, pivot);
-
-    let (mid, was_partitioned) = {
-        let (pivot, v) = v.split_at_mut(1);
-
-        // Read the pivot into a stack-allocated variable for efficiency.
-        let write_on_drop = WriteOnDrop {
-            value: unsafe { Some(ptr::read(&pivot[0])) },
-            dest: &mut pivot[0],
-        };
-        let pivot = write_on_drop.value.as_ref().unwrap();
-
-        // Find the first pair of out-of-order elements.
-        let mut l = 0;
-        let mut r = v.len();
-        unsafe {
-            while l < r && is_less(v.get_unchecked(l), pivot) {
-                l += 1;
-            }
-            while l < r && !is_less(v.get_unchecked(r - 1), pivot) {
-                r -= 1;
-            }
-        }
-
-        (l + partition_in_blocks(&mut v[l..r], pivot, is_less), l >= r)
-    };
-
-    v.swap(0, mid);
-    (mid, was_partitioned)
-}
-
-/// Partitions `v` into elements equal to `v[pivot]` followed by elements greater than `v[pivot]`.
-/// It is assumed that `v` does not contain elements smaller than `v[pivot]`.
-fn partition_equal<T, F>(v: &mut [T], pivot: usize, is_less: &mut F) -> usize
-    where F: FnMut(&T, &T) -> bool
-{
-    v.swap(0, pivot);
-    let (pivot, v) = v.split_at_mut(1);
-
-    // Read the pivot into a stack-allocated variable for efficiency.
-    let write_on_drop = WriteOnDrop {
-        value: unsafe { Some(ptr::read(&pivot[0])) },
-        dest: &mut pivot[0],
-    };
-    let pivot = write_on_drop.value.as_ref().unwrap();
-
-    let mut l = 0;
-    let mut r = v.len();
-    loop {
-        unsafe {
-            while l < r && !is_less(pivot, v.get_unchecked(l)) {
-                l += 1;
-            }
-            while l < r && is_less(pivot, v.get_unchecked(r - 1)) {
-                r -= 1;
-            }
-            if l >= r {
-                break;
-            }
-            r -= 1;
-            ptr::swap(v.get_unchecked_mut(l), v.get_unchecked_mut(r));
-            l += 1;
-        }
-    }
-
-    // Add 1 to also account for the pivot at index 0.
-    l + 1
-}
-
-/// Scatters some elements around in an attempt to break patterns that might cause imbalanced
-/// partitions in quicksort.
-#[cold]
-fn break_patterns<T>(v: &mut [T]) {
-    let len = v.len();
-
-    if len >= 8 {
-        let mut rnd = len as u32;
-        rnd ^= rnd << 13;
-        rnd ^= rnd >> 17;
-        rnd ^= rnd << 5;
-
-        let mask = (len / 4).next_power_of_two() - 1;
-        let rnd = rnd as usize & mask;
-        debug_assert!(rnd < len / 2);
-
-        let a = len / 4 * 2;
-        let b = len / 4 + rnd;
-
-        // Swap neighbourhoods of `a` and `b`.
-        for i in 0..3 {
-            v.swap(a - 1 + i, b - 1 + i);
-        }
-    }
-}
-
-/// Chooses a pivot in `v` and returns it's index.
-///
-/// Elements of `v` might be shuffled in the process.
-fn choose_pivot<T, F>(v: &mut [T], is_less: &mut F) -> usize
-    where F: FnMut(&T, &T) -> bool
-{
-    const SHORTEST_MEDIAN_OF_MEDIANS: usize = 90;
-    const MAX_SWAPS: usize = 4 * 3;
-
-    let len = v.len();
-    let mut a = len / 4 * 1;
-    let mut b = len / 4 * 2;
-    let mut c = len / 4 * 3;
-    let mut swaps = 0;
-
-    if len >= 8 {
-        let mut sort2 = |a: &mut usize, b: &mut usize| unsafe {
-            if is_less(v.get_unchecked(*b), v.get_unchecked(*a)) {
-                ptr::swap(a, b);
-                swaps += 1;
-            }
-        };
-
-        let mut sort3 = |a: &mut usize, b: &mut usize, c: &mut usize| {
-            sort2(a, b);
-            sort2(b, c);
-            sort2(a, b);
-        };
-
-        if len >= SHORTEST_MEDIAN_OF_MEDIANS {
-            let mut sort_adjacent = |a: &mut usize| {
-                let tmp = *a;
-                sort3(&mut (tmp - 1), a, &mut (tmp + 1));
-            };
-
-            sort_adjacent(&mut a);
-            sort_adjacent(&mut b);
-            sort_adjacent(&mut c);
-        }
-        sort3(&mut a, &mut b, &mut c);
-    }
-
-    if swaps < MAX_SWAPS {
-        b
-    } else {
-        v.reverse();
-        len - 1 - b
-    }
-}
-
-/// Sorts `v` recursively.
-///
-/// If the slice had a predecessor in the original array, it is specified as `pred`.
-///
-/// `limit` is the number of allowed imbalanced partitions before switching to `heapsort`. If zero,
-/// this function will immediately switch to heapsort.
-fn recurse<'a, T, F>(mut v: &'a mut [T], is_less: &mut F, mut pred: Option<&'a T>, mut limit: usize)
-    where F: FnMut(&T, &T) -> bool
-{
-    // If `v` has length up to `insertion_len`, simply switch to insertion sort because it is going
-    // to perform better than quicksort. For bigger types `T`, the threshold is smaller.
-    let max_insertion = if mem::size_of::<T>() <= 2 * mem::size_of::<usize>() {
-        32
-    } else {
-        16
-    };
-
-    // This is `true` if the last partitioning was balanced.
-    let mut was_balanced = true;
-
-    loop {
-        let len = v.len();
-        if len <= max_insertion {
-            insertion_sort(v, is_less);
-            return;
-        }
-
-        if limit == 0 {
-            heapsort(v, is_less);
-            return;
-        }
-
-        // If the last partitioning was imbalanced, try breaking patterns in the slice by shuffling
-        // some elements around. Hopefully we'll choose a better pivot this time.
-        if !was_balanced {
-            break_patterns(v);
-            limit -= 1;
-        }
-
-        let pivot = choose_pivot(v, is_less);
-
-        // If the chosen pivot is equal to the predecessor, then it's the smallest element in the
-        // slice. Partition the slice into elements equal to and elements greater than the pivot.
-        // This case is usually hit when the slice contains many duplicate elements.
-        if let Some(p) = pred {
-            if !is_less(p, &v[pivot]) {
-                let mid = partition_equal(v, pivot, is_less);
-                v = &mut {v}[mid..];
-                continue;
-            }
-        }
-
-        let (mid, was_partitioned) = partition(v, pivot, is_less);
-        was_balanced = cmp::min(mid, len - mid) >= len / 8;
-
-        // If the partitioning is decently balanced and the slice was already partitioned, there
-        // are good chances it is also completely sorted. If so, we're done.
-        if was_balanced && was_partitioned && v.windows(2).all(|w| !is_less(&w[1], &w[0])) {
-            return;
-        }
-
-        let (left, right) = {v}.split_at_mut(mid);
-        let (pivot, right) = right.split_at_mut(1);
-
-        // Recurse into the smaller side only, in order to minimize the total number of recursive
-        // calls and consume less stack space.
-        if left.len() < right.len() {
-            recurse(left, is_less, pred, limit);
-            v = right;
-            pred = Some(&pivot[0]);
-        } else {
-            recurse(right, is_less, Some(&pivot[0]), limit);
-            v = left;
-        }
-    }
-}
-
-/// Sorts `v` using quicksort.
-fn quicksort<T, F>(v: &mut [T], mut is_less: F)
-    where F: FnMut(&T, &T) -> bool
-{
-    // Sorting has no meaningful behavior on zero-sized types.
-    if mem::size_of::<T>() == 0 {
-        return;
-    }
-
-    let limit = 64 - (v.len() as u64).leading_zeros() as usize + 1;
-    recurse(v, &mut is_less, None, limit);
-}
-
-/// Sorts a slice.
-///
-/// This sort is in-place, unstable, and `O(n log n)` worst-case.
-///
-/// The implementation is based on Orson Peters' pattern-defeating quicksort.
-///
-/// # Examples
-///
-/// ```
-/// extern crate pdqsort;
-///
-/// let mut v = [-5, 4, 1, -3, 2];
-/// pdqsort::sort(&mut v);
-/// assert!(v == [-5, -3, 1, 2, 4]);
-/// ```
-#[inline]
-pub fn sort<T>(v: &mut [T])
-    where T: Ord
-{
-    quicksort(v, |a, b| a.lt(b));
-}
-
-/// Sorts a slice using `f` to extract a key to compare elements by.
-///
-/// This sort is in-place, unstable, and `O(n log n)` worst-case.
-///
-/// The implementation is based on Orson Peters' pattern-defeating quicksort.
-///
-/// # Examples
-///
-/// ```
-/// extern crate pdqsort;
-///
-/// let mut v = [-5i32, 4, 1, -3, 2];
-/// pdqsort::sort_by_key(&mut v, |k| k.abs());
-/// assert!(v == [1, 2, -3, 4, -5]);
-/// ```
-#[inline]
-pub fn sort_by_key<T, B, F>(v: &mut [T], mut f: F)
-    where F: FnMut(&T) -> B,
-          B: Ord
-{
-    quicksort(v, |a, b| f(a).lt(&f(b)))
-}
-
-/// Sorts a slice using `compare` to compare elements.
-///
-/// This sort is in-place, unstable, and `O(n log n)` worst-case.
-///
-/// The implementation is based on Orson Peters' pattern-defeating quicksort.
-///
-/// # Examples
-///
-/// ```
-/// extern crate pdqsort;
-///
-/// let mut v = [5, 4, 1, 3, 2];
-/// pdqsort::sort_by(&mut v, |a, b| a.cmp(b));
-/// assert!(v == [1, 2, 3, 4, 5]);
-///
-/// // reverse sorting
-/// pdqsort::sort_by(&mut v, |a, b| b.cmp(a));
-/// assert!(v == [5, 4, 3, 2, 1]);
-/// ```
-#[inline]
-pub fn sort_by<T, F>(v: &mut [T], mut compare: F)
-    where F: FnMut(&T, &T) -> Ordering
-{
-    quicksort(v, |a, b| compare(a, b) == Ordering::Less);
-}
-
-#[cfg(test)]
-mod tests {
-    extern crate std;
-    extern crate rand;
-
-    use self::rand::{Rng, thread_rng};
-    use self::std::cmp::Ordering::{Greater, Less};
-    use self::std::prelude::v1::*;
-
-    #[test]
-    fn test_sort_zero_sized_type() {
-        // Should not panic.
-        [(); 10].sort();
-        [(); 100].sort();
-    }
-
-    #[test]
-    fn test_pdqsort() {
-        let mut rng = thread_rng();
-        for n in 0..16 {
-            for l in 0..16 {
-                let mut v = rng.gen_iter::<u64>()
-                    .map(|x| x % (1 << l))
-                    .take((1 << n))
-                    .collect::<Vec<_>>();
-                let mut v1 = v.clone();
-
-                super::sort(&mut v);
-                assert!(v.windows(2).all(|w| w[0] <= w[1]));
-
-                v1.sort_by(|a, b| a.cmp(b));
-                assert!(v1.windows(2).all(|w| w[0] <= w[1]));
-
-                v1.sort_by(|a, b| b.cmp(a));
-                assert!(v1.windows(2).all(|w| w[0] >= w[1]));
-            }
-        }
-
-        let mut v = [0xDEADBEEFu64];
-        super::sort(&mut v);
-        assert!(v == [0xDEADBEEF]);
-    }
-
-    #[test]
-    fn test_heapsort() {
-        let mut rng = thread_rng();
-        for n in 0..16 {
-            for l in 0..16 {
-                let mut v = rng.gen_iter::<u64>()
-                    .map(|x| x % (1 << l))
-                    .take((1 << n))
-                    .collect::<Vec<_>>();
-                let mut v1 = v.clone();
-
-                super::heapsort(&mut v, &mut |a, b| a.lt(b));
-                assert!(v.windows(2).all(|w| w[0] <= w[1]));
-
-                v1.sort_by(|a, b| a.cmp(b));
-                assert!(v1.windows(2).all(|w| w[0] <= w[1]));
-
-                v1.sort_by(|a, b| b.cmp(a));
-                assert!(v1.windows(2).all(|w| w[0] >= w[1]));
-            }
-        }
-
-        let mut v = [0xDEADBEEFu64];
-        super::heapsort(&mut v, &mut |a, b| a.lt(b));
-        assert!(v == [0xDEADBEEF]);
-    }
-
-    #[test]
-    fn test_crazy_compare() {
-        let mut rng = thread_rng();
-
-        let mut v = rng.gen_iter::<u64>()
-            .map(|x| x % 1000)
-            .take(100_000)
-            .collect::<Vec<_>>();
-
-        // Even though comparison is non-sensical, sorting must not panic.
-        super::sort_by(&mut v, |_, _| *rng.choose(&[Less, Greater]).unwrap());
-    }
-}
diff --git a/toolkit/content/tests/reftests/reftest.list b/toolkit/content/tests/reftests/reftest.list
index 3cb36a171b4d..456ef85c6a1c 100644
--- a/toolkit/content/tests/reftests/reftest.list
+++ b/toolkit/content/tests/reftests/reftest.list
@@ -1,5 +1,5 @@
 random-if(cocoaWidget||(/^Windows\x20NT\x206\.2/.test(http.oscpu)&&isDebugBuild)) == bug-442419-progressmeter-max.xul bug-442419-progressmeter-max-ref.xul # fails most of the time on Mac because progress meter animates
-!= textbox-multiline-default-value.xul textbox-multiline-empty.xul
+fails-if(styloVsGecko) != textbox-multiline-default-value.xul textbox-multiline-empty.xul # bug 1408811
 == videocontrols-dynamically-add-cc.html videocontrols-dynamically-add-cc-ref.html
 == audio-with-bogus-url.html audio-with-bogus-url-ref.html
 == audio-dynamically-change-small-width.html audio-dynamically-change-small-width-ref.html
diff --git a/toolkit/library/gtest/rust/Cargo.lock b/toolkit/library/gtest/rust/Cargo.lock
index 8510b6189668..519698dd951d 100644
--- a/toolkit/library/gtest/rust/Cargo.lock
+++ b/toolkit/library/gtest/rust/Cargo.lock
@@ -989,11 +989,6 @@ dependencies = [
  "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "pdqsort"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "peeking_take_while"
 version = "0.1.2"
@@ -1327,7 +1322,6 @@ dependencies = [
  "ordered-float 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "owning_ref 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "pdqsort 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "precomputed-hash 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1764,7 +1758,6 @@ dependencies = [
 "checksum owning_ref 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "cdf84f41639e037b484f93433aa3897863b561ed65c6e59c7073d7c561710f37"
 "checksum parking_lot 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "37f364e2ce5efa24c7d0b6646d5bb61145551a0112f107ffd7499f1a3e322fbd"
 "checksum parking_lot_core 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "a25dd36576d01cca115881dc920b1f0dd0037303ed8cfa0c5d0a4966151757f7"
-"checksum pdqsort 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "ceca1642c89148ca05611cc775a0c383abef355fc4907c4e95f49f7b09d6287c"
 "checksum peeking_take_while 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "19b17cddbe7ec3f8bc800887bab5e717348c95ea2ca0b1bf0837fb964dc67099"
 "checksum percent-encoding 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "de154f638187706bde41d9b4738748933d64e6b37bdbffc0b47a97d16a6ae356"
 "checksum phf 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)" = "cb325642290f28ee14d8c6201159949a872f220c62af6e110a56ea914fbe42fc"
diff --git a/toolkit/library/rust/Cargo.lock b/toolkit/library/rust/Cargo.lock
index b4a11da3b2b5..e2208b17b69d 100644
--- a/toolkit/library/rust/Cargo.lock
+++ b/toolkit/library/rust/Cargo.lock
@@ -977,11 +977,6 @@ dependencies = [
  "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "pdqsort"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "peeking_take_while"
 version = "0.1.2"
@@ -1319,7 +1314,6 @@ dependencies = [
  "ordered-float 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "owning_ref 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "pdqsort 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "precomputed-hash 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1776,7 +1770,6 @@ dependencies = [
 "checksum owning_ref 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "cdf84f41639e037b484f93433aa3897863b561ed65c6e59c7073d7c561710f37"
 "checksum parking_lot 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "37f364e2ce5efa24c7d0b6646d5bb61145551a0112f107ffd7499f1a3e322fbd"
 "checksum parking_lot_core 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "a25dd36576d01cca115881dc920b1f0dd0037303ed8cfa0c5d0a4966151757f7"
-"checksum pdqsort 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "ceca1642c89148ca05611cc775a0c383abef355fc4907c4e95f49f7b09d6287c"
 "checksum peeking_take_while 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "19b17cddbe7ec3f8bc800887bab5e717348c95ea2ca0b1bf0837fb964dc67099"
 "checksum percent-encoding 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "de154f638187706bde41d9b4738748933d64e6b37bdbffc0b47a97d16a6ae356"
 "checksum phf 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)" = "cb325642290f28ee14d8c6201159949a872f220c62af6e110a56ea914fbe42fc"
diff --git a/toolkit/locales/en-US/chrome/global/aboutSupport.properties b/toolkit/locales/en-US/chrome/global/aboutSupport.properties
index 03524f39028b..c7baae10ff56 100644
--- a/toolkit/locales/en-US/chrome/global/aboutSupport.properties
+++ b/toolkit/locales/en-US/chrome/global/aboutSupport.properties
@@ -119,6 +119,7 @@ canSandboxMedia = Media Plugin Sandboxing
 contentSandboxLevel = Content Process Sandbox Level
 effectiveContentSandboxLevel = Effective Content Process Sandbox Level
 sandboxProcType.content = content
+sandboxProcType.file = file content
 sandboxProcType.mediaPlugin = media plugin
 
 # LOCALIZATION NOTE %1$S and %2$S will be replaced with the number of remote and the total number
diff --git a/toolkit/modules/AppConstants.jsm b/toolkit/modules/AppConstants.jsm
index db6176d95b47..327f5e796958 100644
--- a/toolkit/modules/AppConstants.jsm
+++ b/toolkit/modules/AppConstants.jsm
@@ -180,13 +180,6 @@ this.AppConstants = Object.freeze({
   false,
 #endif
 
-  E10S_TESTING_ONLY:
-#ifdef E10S_TESTING_ONLY
-  true,
-#else
-  false,
-#endif
-
   DEBUG:
 #ifdef DEBUG
   true,
diff --git a/toolkit/mozapps/installer/windows/nsis/common.nsh b/toolkit/mozapps/installer/windows/nsis/common.nsh
index ff37411794c1..0f740979d8db 100755
--- a/toolkit/mozapps/installer/windows/nsis/common.nsh
+++ b/toolkit/mozapps/installer/windows/nsis/common.nsh
@@ -7403,18 +7403,39 @@
 !endif
 
 /**
- * Modified version of the __NSD_SetStretchedImage macro from nsDialogs.nsh that
- * supports transparency. See nsDialogs documentation for additional info.
+ * Draws an image file (BMP, GIF, or JPG) onto a bitmap control, with scaling.
+ * Adapted from https://stackoverflow.com/a/13405711/1508094
+ *
+ * @param CONTROL bitmap control created by NSD_CreateBitmap
+ * @param IMAGE path to image file to draw to the bitmap
+ * @param HANDLE output bitmap handle which must be freed via NSD_FreeImage
+ *               after nsDialogs::Show has been called
  */
-!macro __SetStretchedTransparentImage CONTROL IMAGE HANDLE
-  Push $0
-  Push $1
-  Push $2
-  Push $R0
+!macro __SetStretchedImageOLE CONTROL IMAGE HANDLE
+  !ifndef IID_IPicture
+    !define IID_IPicture {7BF80980-BF32-101A-8BBB-00AA00300CAB}
+  !endif
+  !ifndef SRCCOPY
+    !define SRCCOPY 0xCC0020
+  !endif
+  !ifndef HALFTONE
+    !define HALFTONE 4
+  !endif
+
+  Push $0 ; HANDLE
+  Push $1 ; memory DC
+  Push $2 ; IPicture created from IMAGE
+  Push $3 ; HBITMAP obtained from $2
+  Push $4 ; BITMAPINFO obtained from $3
+  Push $5 ; width of IMAGE
+  Push $6 ; height of IMAGE
+  Push $7 ; width of CONTROL
+  Push $8 ; height of CONTROL
+  Push $R0 ; CONTROL
 
   StrCpy $R0 ${CONTROL} ; in case ${CONTROL} is $0
-  StrCpy $1 ""
-  StrCpy $2 ""
+  StrCpy $7 ""
+  StrCpy $8 ""
 
   System::Call '*(i, i, i, i) i.s'
   Pop $0
@@ -7423,25 +7444,50 @@
     System::Call 'user32::GetClientRect(i R0, i r0)'
     System::Call '*$0(i, i, i .s, i .s)'
     System::Free $0
-    Pop $1
-    Pop $2
+    Pop $7
+    Pop $8
   ${EndIf}
 
-  System::Call 'user32::LoadImageW(i 0, t s, i ${IMAGE_BITMAP}, i r1, i r2, \
-                                   i ${MOZ_LOADTRANSPARENT}) i .s' "${IMAGE}"
-  Pop $0
-  SendMessage $R0 ${STM_SETIMAGE} ${IMAGE_BITMAP} $0
-
-  SetCtlColors $R0 "" transparent
-  ${NSD_AddExStyle} $R0 ${WS_EX_TRANSPARENT}|${WS_EX_TOPMOST}
+  ${If} $7 > 0
+  ${AndIf} $8 > 0
+    System::Call 'oleaut32::OleLoadPicturePath(w"${IMAGE}",i0,i0,i0,g"${IID_IPicture}",*i.r2)i.r1'
+    ${If} $1 = 0
+      System::Call 'user32::GetDC(i0)i.s'
+      System::Call 'gdi32::CreateCompatibleDC(iss)i.r1'
+      System::Call 'gdi32::CreateCompatibleBitmap(iss,ir7,ir8)i.r0'
+      System::Call 'user32::ReleaseDC(i0,is)'
+      System::Call '$2->3(*i.r3)i.r4' ; IPicture->get_Handle
+      ${If} $4 = 0
+        System::Call 'gdi32::SetStretchBltMode(ir1,i${HALFTONE})'
+        System::Call '*(&i40,&i1024)i.r4' ; BITMAP / BITMAPINFO
+        System::Call 'gdi32::GetObject(ir3,i24,ir4)'
+        System::Call 'gdi32::SelectObject(ir1,ir0)i.s'
+        System::Call '*$4(i40,i.r5,i.r6,i0,i,i.s)' ; Grab size and bits-ptr AND init as BITMAPINFOHEADER
+        System::Call 'gdi32::GetDIBits(ir1,ir3,i0,i0,i0,ir4,i0)' ; init BITMAPINFOHEADER
+        System::Call 'gdi32::GetDIBits(ir1,ir3,i0,i0,i0,ir4,i0)' ; init BITMAPINFO
+        System::Call 'gdi32::StretchDIBits(ir1,i0,i0,ir7,ir8,i0,i0,ir5,ir6,is,ir4,i0,i${SRCCOPY})'
+        System::Call 'gdi32::SelectObject(ir1,is)'
+        System::Free $4
+        SendMessage $R0 ${STM_SETIMAGE} ${IMAGE_BITMAP} $0
+      ${EndIf}
+      System::Call 'gdi32::DeleteDC(ir1)'
+      System::Call '$2->2()' ; IPicture->release()
+    ${EndIf}
+  ${EndIf}
 
   Pop $R0
+  Pop $8
+  Pop $7
+  Pop $6
+  Pop $5
+  Pop $4
+  Pop $3
   Pop $2
   Pop $1
   Exch $0
   Pop ${HANDLE}
 !macroend
-!define SetStretchedTransparentImage "!insertmacro __SetStretchedTransparentImage"
+!define SetStretchedImageOLE "!insertmacro __SetStretchedImageOLE"
 
 /**
  * Removes a single style from a control.
diff --git a/toolkit/themes/osx/reftests/reftest.list b/toolkit/themes/osx/reftests/reftest.list
index 27034dd8629c..5399125471ef 100644
--- a/toolkit/themes/osx/reftests/reftest.list
+++ b/toolkit/themes/osx/reftests/reftest.list
@@ -1,5 +1,5 @@
-skip-if(!cocoaWidget) == 482681.xul 482681-ref.xul
-skip-if(!cocoaWidget) == radiosize.xul radiosize-ref.xul
-skip-if(!cocoaWidget) == checkboxsize.xul checkboxsize-ref.xul
+fails-if(stylo) skip-if(!cocoaWidget) == 482681.xul 482681-ref.xul # bug 1408235
+fails-if(stylo) skip-if(!cocoaWidget) == radiosize.xul radiosize-ref.xul # bug 1408235
+fails-if(stylo) skip-if(!cocoaWidget) == checkboxsize.xul checkboxsize-ref.xul # bug 1408235
 skip-if(!cocoaWidget) == baseline.xul about:blank
-skip-if(!cocoaWidget) == nostretch.xul nostretch-ref.xul
+fails-if(stylo) skip-if(!cocoaWidget) == nostretch.xul nostretch-ref.xul # bug 1408824
diff --git a/view/crashtests/crashtests.list b/view/crashtests/crashtests.list
index 2156501ce0d2..f29b9412b470 100644
--- a/view/crashtests/crashtests.list
+++ b/view/crashtests/crashtests.list
@@ -2,7 +2,7 @@ load 38589-1.xul
 load 64049-1.html
 load 281743-1.html
 load 323497-1.html
-load 382756-1.xul
+asserts-if(stylo,3) load 382756-1.xul # bug 1397644
 load 387745-1.svg
 load 399852.html
 load 429315-1.html
diff --git a/widget/ContentCache.cpp b/widget/ContentCache.cpp
index 09c297121cbf..59b55584dd2c 100644
--- a/widget/ContentCache.cpp
+++ b/widget/ContentCache.cpp
@@ -15,6 +15,9 @@
 #include "mozilla/TextComposition.h"
 #include "mozilla/TextEvents.h"
 #include "mozilla/dom/TabParent.h"
+#ifdef MOZ_CRASHREPORTER
+#include "nsExceptionHandler.h"
+#endif // #ifdef MOZ_CRASHREPORTER
 #include "nsIWidget.h"
 
 namespace mozilla {
@@ -1110,6 +1113,10 @@ ContentCacheInParent::OnCompositionEvent(const WidgetCompositionEvent& aEvent)
      GetBoolName(mWidgetHasComposition), mPendingCompositionCount,
      mCommitStringByRequest));
 
+#ifdef MOZ_CRASHREPORTER
+  mDispatchedEventMessages.AppendElement(aEvent.mMessage);
+#endif // #ifdef MOZ_CRASHREPORTER
+
   // We must be able to simulate the selection because
   // we might not receive selection updates in time
   if (!mWidgetHasComposition) {
@@ -1186,6 +1193,10 @@ ContentCacheInParent::OnSelectionEvent(
      GetBoolName(aSelectionEvent.mUseNativeLineBreak), mPendingEventsNeedingAck,
      GetBoolName(mWidgetHasComposition), mPendingCompositionCount));
 
+#ifdef MOZ_CRASHREPORTER
+  mDispatchedEventMessages.AppendElement(aSelectionEvent.mMessage);
+#endif // #ifdef MOZ_CRASHREPORTER
+
   mPendingEventsNeedingAck++;
 }
 
@@ -1201,9 +1212,30 @@ ContentCacheInParent::OnEventNeedingAckHandled(nsIWidget* aWidget,
      "aMessage=%s), mPendingEventsNeedingAck=%u, mPendingCompositionCount=%" PRIu8,
      this, aWidget, ToChar(aMessage), mPendingEventsNeedingAck, mPendingCompositionCount));
 
+#ifdef MOZ_CRASHREPORTER
+  mReceivedEventMessages.AppendElement(aMessage);
+#endif // #ifdef MOZ_CRASHREPORTER
+
   if (WidgetCompositionEvent::IsFollowedByCompositionEnd(aMessage) ||
       aMessage == eCompositionCommitRequestHandled) {
-    MOZ_RELEASE_ASSERT(mPendingCompositionCount > 0);
+
+#ifdef MOZ_CRASHREPORTER
+    if (mPendingCompositionCount == 1) {
+      RemoveUnnecessaryEventMessageLog();
+    }
+#endif // #ifdef MOZ_CRASHREPORTER
+
+    if (NS_WARN_IF(!mPendingCompositionCount)) {
+#ifdef MOZ_CRASHREPORTER
+      nsPrintfCString info("There is no pending composition but received %s "
+                           "message from the remote child\n\n",
+                           ToChar(aMessage));
+      AppendEventMessageLog(info);
+      CrashReporter::AppendAppNotesToCrashReport(info);
+#endif // #ifdef MOZ_CRASHREPORTER
+      MOZ_CRASH("No pending composition but received unexpected commit event");
+    }
+
     mPendingCompositionCount--;
     // Forget composition string only when the latest composition string is
     // handled in the remote process because if there is 2 or more pending
@@ -1219,7 +1251,16 @@ ContentCacheInParent::OnEventNeedingAckHandled(nsIWidget* aWidget,
     mPendingCommitLength = 0;
   }
 
-  MOZ_RELEASE_ASSERT(mPendingEventsNeedingAck > 0);
+  if (NS_WARN_IF(!mPendingEventsNeedingAck)) {
+#ifdef MOZ_CRASHREPORTER
+    nsPrintfCString info("There is no pending events but received %s "
+                         "message from the remote child\n\n",
+                         ToChar(aMessage));
+    AppendEventMessageLog(info);
+    CrashReporter::AppendAppNotesToCrashReport(info);
+#endif // #ifdef MOZ_CRASHREPORTER
+    MOZ_CRASH("No pending event message but received unexpected event");
+  }
   if (--mPendingEventsNeedingAck) {
     return;
   }
@@ -1409,6 +1450,61 @@ ContentCacheInParent::FlushPendingNotifications(nsIWidget* aWidget)
   }
 }
 
+#ifdef MOZ_CRASHREPORTER
+
+void
+ContentCacheInParent::RemoveUnnecessaryEventMessageLog()
+{
+  bool foundLastCompositionStart = false;
+  for (size_t i = mDispatchedEventMessages.Length(); i > 1; i--) {
+    if (mDispatchedEventMessages[i - 1] != eCompositionStart) {
+      continue;
+    }
+    if (!foundLastCompositionStart) {
+      // Find previous eCompositionStart of the latest eCompositionStart.
+      foundLastCompositionStart = true;
+      continue;
+    }
+    // Remove the messages before the last 2 sets of composition events.
+    mDispatchedEventMessages.RemoveElementsAt(0, i - 1);
+    break;
+  }
+  foundLastCompositionStart = false;
+  for (size_t i = mReceivedEventMessages.Length(); i > 1; i--) {
+    if (mReceivedEventMessages[i - 1] != eCompositionStart) {
+      continue;
+    }
+    if (!foundLastCompositionStart) {
+      // Find previous eCompositionStart of the latest eCompositionStart.
+      foundLastCompositionStart = true;
+      continue;
+    }
+    // Remove the messages before the last 2 sets of composition events.
+    mReceivedEventMessages.RemoveElementsAt(0, i - 1);
+    break;
+  }
+}
+
+void
+ContentCacheInParent::AppendEventMessageLog(nsACString& aLog) const
+{
+  aLog.AppendLiteral("Dispatched Event Message Log:\n");
+  for (EventMessage message : mDispatchedEventMessages) {
+    aLog.AppendLiteral("  ");
+    aLog.Append(ToChar(message));
+    aLog.AppendLiteral("\n");
+  }
+  aLog.AppendLiteral("\nReceived Event Message Log:\n");
+  for (EventMessage message : mReceivedEventMessages) {
+    aLog.AppendLiteral("  ");
+    aLog.Append(ToChar(message));
+    aLog.AppendLiteral("\n");
+  }
+  aLog.AppendLiteral("\n");
+}
+
+#endif // #ifdef MOZ_CRASHREPORTER
+
 /*****************************************************************************
  * mozilla::ContentCache::TextRectArray
  *****************************************************************************/
diff --git a/widget/ContentCache.h b/widget/ContentCache.h
index 6f3e67387be9..90c18861238c 100644
--- a/widget/ContentCache.h
+++ b/widget/ContentCache.h
@@ -410,6 +410,12 @@ private:
   IMENotification mPendingLayoutChange;
   IMENotification mPendingCompositionUpdate;
 
+#ifdef MOZ_CRASHREPORTER
+  // Log of event messages to be output to crash report.
+  nsTArray<EventMessage> mDispatchedEventMessages;
+  nsTArray<EventMessage> mReceivedEventMessages;
+#endif // #ifdef MOZ_CRASHREPORTER
+
   // mTabParent is owner of the instance.
   dom::TabParent& MOZ_NON_OWNING_REF mTabParent;
   // mCompositionString is composition string which were sent to the remote
@@ -464,6 +470,19 @@ private:
                          LayoutDeviceIntRect& aUnionTextRect) const;
 
   void FlushPendingNotifications(nsIWidget* aWidget);
+
+#ifdef MOZ_CRASHREPORTER
+  /**
+   * Remove unnecessary messages from mDispatchedEventMessages and
+   * mReceivedEventMessages.
+   */
+  void RemoveUnnecessaryEventMessageLog();
+
+  /**
+   * Append event message log to aLog.
+   */
+  void AppendEventMessageLog(nsACString& aLog) const;
+#endif // #ifdef MOZ_CRASHREPORTER
 };
 
 } // namespace mozilla
diff --git a/widget/LookAndFeel.h b/widget/LookAndFeel.h
index c62b5395c390..8a869f96a03c 100644
--- a/widget/LookAndFeel.h
+++ b/widget/LookAndFeel.h
@@ -388,13 +388,6 @@ public:
      */
     eIntID_SwipeAnimationEnabled,
 
-    /*
-     * A boolean value indicating whether or not the device has a hardware
-     * home button. Used on gaia to determine whether a home button
-     * is shown.
-     */
-     eIntID_PhysicalHomeButton,
-
      /*
       * Controls whether overlay scrollbars display when the user moves
       * the mouse in a scrollable frame.
diff --git a/widget/headless/HeadlessLookAndFeelGTK.cpp b/widget/headless/HeadlessLookAndFeelGTK.cpp
index af1cd056ce0e..58760f4e09db 100644
--- a/widget/headless/HeadlessLookAndFeelGTK.cpp
+++ b/widget/headless/HeadlessLookAndFeelGTK.cpp
@@ -263,9 +263,6 @@ HeadlessLookAndFeel::GetIntImpl(IntID aID, int32_t &aResult)
     case eIntID_SwipeAnimationEnabled:
       aResult = 0;
       break;
-    case eIntID_PhysicalHomeButton:
-      aResult = 0;
-      break;
     case eIntID_ScrollbarDisplayOnMouseMove:
       aResult = 0;
       break;
diff --git a/widget/nsDeviceContextSpecProxy.cpp b/widget/nsDeviceContextSpecProxy.cpp
index 7ee494433efb..05d5d90688ed 100644
--- a/widget/nsDeviceContextSpecProxy.cpp
+++ b/widget/nsDeviceContextSpecProxy.cpp
@@ -19,6 +19,7 @@
 #include "nsIPrintSession.h"
 #include "nsIPrintSettings.h"
 #include "nsIUUIDGenerator.h"
+#include "private/pprio.h"
 
 using mozilla::Unused;
 
@@ -143,48 +144,12 @@ nsDeviceContextSpecProxy::GetPrintingScale()
   return mRealDeviceContextSpec->GetPrintingScale();
 }
 
-nsresult
-nsDeviceContextSpecProxy::CreateUniqueTempPath(nsACString& aFilePath)
-{
-  MOZ_ASSERT(mRecordingDir);
-  MOZ_ASSERT(mUuidGenerator);
-
-  nsID uuid;
-  nsresult rv = mUuidGenerator->GenerateUUIDInPlace(&uuid);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  char uuidChars[NSID_LENGTH];
-  uuid.ToProvidedString(uuidChars);
-  mRecordingFileName.AssignASCII(uuidChars);
-
-  nsCOMPtr<nsIFile> recordingFile;
-  rv = mRecordingDir->Clone(getter_AddRefs(recordingFile));
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  rv = recordingFile->AppendNative(mRecordingFileName);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  return recordingFile->GetNativePath(aFilePath);
-}
-
 NS_IMETHODIMP
 nsDeviceContextSpecProxy::BeginDocument(const nsAString& aTitle,
                                         const nsAString& aPrintToFileName,
                                         int32_t aStartPage, int32_t aEndPage)
 {
-  nsAutoCString recordingPath;
-  nsresult rv = CreateUniqueTempPath(recordingPath);
-  if (NS_FAILED(rv)) {
-    return rv;
-  }
-
-  mRecorder = new mozilla::gfx::DrawEventRecorderFile(recordingPath.get());
+  mRecorder = new mozilla::layout::DrawEventRecorderPRFileDesc();
   return mRemotePrintJob->InitializePrint(nsString(aTitle),
                                           nsString(aPrintToFileName),
                                           aStartPage, aEndPage);
@@ -207,16 +172,7 @@ nsDeviceContextSpecProxy::AbortDocument()
 NS_IMETHODIMP
 nsDeviceContextSpecProxy::BeginPage()
 {
-  // Reopen the file, if necessary, ready for the next page.
-  if (!mRecorder->IsOpen()) {
-    nsAutoCString recordingPath;
-    nsresult rv = CreateUniqueTempPath(recordingPath);
-    if (NS_FAILED(rv)) {
-      return rv;
-    }
-
-    mRecorder->OpenNew(recordingPath.get());
-  }
+  mRecorder->OpenFD(mRemotePrintJob->GetNextPageFD());
 
   return NS_OK;
 }
@@ -226,7 +182,7 @@ nsDeviceContextSpecProxy::EndPage()
 {
   // Send the page recording to the parent.
   mRecorder->Close();
-  mRemotePrintJob->ProcessPage(mRecordingFileName);
+  mRemotePrintJob->ProcessPage();
 
   return NS_OK;
 }
diff --git a/widget/nsDeviceContextSpecProxy.h b/widget/nsDeviceContextSpecProxy.h
index adde3cc11939..d0ef3f9d3da9 100644
--- a/widget/nsDeviceContextSpecProxy.h
+++ b/widget/nsDeviceContextSpecProxy.h
@@ -10,16 +10,13 @@
 #include "nsIDeviceContextSpec.h"
 #include "nsCOMPtr.h"
 #include "nsString.h"
+#include "mozilla/layout/printing/DrawEventRecorder.h"
 
 class nsIFile;
 class nsIPrintSession;
 class nsIUUIDGenerator;
 
 namespace mozilla {
-namespace gfx {
-class DrawEventRecorderFile;
-}
-
 namespace layout {
 class RemotePrintJobChild;
 }
@@ -63,7 +60,7 @@ private:
   nsCOMPtr<nsIPrintSession> mPrintSession;
   nsCOMPtr<nsIDeviceContextSpec> mRealDeviceContextSpec;
   RefPtr<mozilla::layout::RemotePrintJobChild> mRemotePrintJob;
-  RefPtr<mozilla::gfx::DrawEventRecorderFile> mRecorder;
+  RefPtr<mozilla::layout::DrawEventRecorderPRFileDesc> mRecorder;
   nsCOMPtr<nsIFile> mRecordingDir;
   nsCOMPtr<nsIUUIDGenerator> mUuidGenerator;
   nsCString mRecordingFileName;
diff --git a/widget/nsXPLookAndFeel.cpp b/widget/nsXPLookAndFeel.cpp
index efa460a8a9a5..8118962b4ac1 100644
--- a/widget/nsXPLookAndFeel.cpp
+++ b/widget/nsXPLookAndFeel.cpp
@@ -117,9 +117,6 @@ nsLookAndFeelIntPref nsXPLookAndFeel::sIntPrefs[] =
   { "ui.tooltipDelay",
     eIntID_TooltipDelay,
     false, 0 },
-  { "ui.physicalHomeButton",
-    eIntID_PhysicalHomeButton,
-    false, 0 },
   { "ui.contextMenuOffsetVertical",
     eIntID_ContextMenuOffsetVertical,
     false, 0 },
diff --git a/xpcom/base/ErrorNames.cpp b/xpcom/base/ErrorNames.cpp
index d58a3e0d8318..ec41e69a65e0 100644
--- a/xpcom/base/ErrorNames.cpp
+++ b/xpcom/base/ErrorNames.cpp
@@ -72,7 +72,7 @@ extern "C" {
 void
 Gecko_GetErrorName(nsresult aRv, nsACString& aName)
 {
-  GetErrorName(aRv, aName);
+  mozilla::GetErrorName(aRv, aName);
 }
 
 }
diff --git a/xpcom/base/nsTraceRefcnt.h b/xpcom/base/nsTraceRefcnt.h
index 73e123a3fe92..173457788fd6 100644
--- a/xpcom/base/nsTraceRefcnt.h
+++ b/xpcom/base/nsTraceRefcnt.h
@@ -3,8 +3,8 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-#ifndef nsTraceRefcnt_h___
-#define nsTraceRefcnt_h___
+#ifndef nsTraceRefcnt_h
+#define nsTraceRefcnt_h
 
 #include <stdio.h> // for FILE
 #include "nscore.h"
@@ -28,13 +28,4 @@ public:
   static void SetActivityIsLegal(bool aLegal);
 };
 
-////////////////////////////////////////////////////////////////////////////////
-// And now for that utility that you've all been asking for...
-
-extern "C" void
-NS_MeanAndStdDev(double aNumberOfValues,
-                 double aSumOfValues, double aSumOfSquaredValues,
-                 double* aMeanResult, double* aStdDevResult);
-
-////////////////////////////////////////////////////////////////////////////////
-#endif
+#endif // nsTraceRefcnt_h
diff --git a/xpcom/threads/nsThreadUtils.h b/xpcom/threads/nsThreadUtils.h
index b47ac3652e77..0236ee388cab 100644
--- a/xpcom/threads/nsThreadUtils.h
+++ b/xpcom/threads/nsThreadUtils.h
@@ -344,6 +344,8 @@ SpinEventLoopUntil(Pred&& aPredicate, nsIThread* aThread = nullptr)
  */
 extern bool NS_IsInCompositorThread();
 
+extern bool NS_IsInVRThread();
+
 //-----------------------------------------------------------------------------
 // Helpers that work with nsCOMPtr: