diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
index 621d2cc76fb0..a70d972b9cfa 100755
--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -5080,6 +5080,7 @@ nsBrowserAccess.prototype = {
                                       fromExternal: aIsExternal,
                                       inBackground: loadInBackground,
                                       forceNotRemote: aForceNotRemote,
+                                      forceBrowserInsertion: true,
                                       opener: aOpener,
                                       });
     let browser = win.gBrowser.getBrowserForTab(tab);
diff --git a/browser/base/content/tabbrowser.xml b/browser/base/content/tabbrowser.xml
index d4973e065ec7..7e96d4d409c7 100644
--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -1514,6 +1514,7 @@
             var aSameProcessAsFrameLoader;
             var aOriginPrincipal;
             var aOpener;
+            var aForceBrowserInsertion;
             if (arguments.length == 2 &&
                 typeof arguments[1] == "object" &&
                 !(arguments[1] instanceof Ci.nsIURI)) {
@@ -1537,6 +1538,7 @@
               aOriginPrincipal          = params.originPrincipal;
               aOpener                   = params.opener;
               aIsPrerendered            = params.isPrerendered;
+              aForceBrowserInsertion    = params.forceBrowserInsertion;
             }
 
             var bgLoad = (aLoadInBackground != null) ? aLoadInBackground :
@@ -1556,6 +1558,7 @@
                                   skipAnimation: aSkipAnimation,
                                   allowMixedContent: aAllowMixedContent,
                                   forceNotRemote: aForceNotRemote,
+                                  forceBrowserInsertion: aForceBrowserInsertion,
                                   preferredRemoteType: aPreferredRemoteType,
                                   noReferrer: aNoReferrer,
                                   userContextId: aUserContextId,
@@ -1710,6 +1713,9 @@
             }
 
             let tab = this.getTabForBrowser(aBrowser);
+            // aBrowser needs to be inserted now if it hasn't been already.
+            this._insertBrowser(tab);
+
             let evt = document.createEvent("Events");
             evt.initEvent("BeforeTabRemotenessChange", true, false);
             tab.dispatchEvent(evt);
@@ -1842,8 +1848,10 @@
             // If we're in a LargeAllocation process, we prefer switching back
             // into a normal content process, as that way we can clean up the
             // L-A process.
-            let preferredRemoteType = aBrowser.remoteType;
-            if (aBrowser.remoteType == E10SUtils.LARGE_ALLOCATION_REMOTE_TYPE) {
+            let currentRemoteType = aBrowser.getAttribute("remoteType") || null;
+            let preferredRemoteType = currentRemoteType;
+
+            if (currentRemoteType == E10SUtils.LARGE_ALLOCATION_REMOTE_TYPE) {
               preferredRemoteType = E10SUtils.DEFAULT_REMOTE_TYPE;
             }
             aOptions.remoteType =
@@ -1854,7 +1862,7 @@
 
             // If this URL can't load in the current browser then flip it to the
             // correct type.
-            if (aBrowser.remoteType != aOptions.remoteType ||
+            if (currentRemoteType != aOptions.remoteType ||
                 aOptions.newFrameloader) {
               let remote = aOptions.remoteType != E10SUtils.NOT_REMOTE;
               return this.updateBrowserRemoteness(aBrowser, remote, aOptions);
@@ -1943,12 +1951,12 @@
           <![CDATA[
             // Supported parameters:
             // userContextId, remote, remoteType, isPreloadBrowser,
-            // uriIsAboutBlank, permanentKey, isPrerendered
+            // uriIsAboutBlank, sameProcessAsFrameLoader, isPrerendered
 
             const NS_XUL = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
 
             let b = document.createElementNS(NS_XUL, "browser");
-            b.permanentKey = aParams.permanentKey || {};
+            b.permanentKey = {};
             b.setAttribute("type", "content");
             b.setAttribute("message", "true");
             b.setAttribute("messagemanagergroup", "browsers");
@@ -2034,59 +2042,92 @@
         </body>
       </method>
 
-      <method name="_linkBrowserToTab">
+      <!--
+        `_createLazyBrowser` will define properties on the unbound lazy browser
+        which correspond to properties defined in XBL which will be bound to
+        the browser when it is inserted into the document.  If any of these
+        properties are accessed by consumers, `_insertBrowser` is called and
+        the browser is inserted to ensure that things don't break.  This list
+        provides the names of properties that may be called while the browser
+        is in its unbound (lazy) state.
+      -->
+      <field name="_browserBindingProperties">[
+        "canGoBack", "canGoForward", "goBack", "goForward", "permitUnload",
+        "reload", "reloadWithFlags", "stop", "loadURI", "loadURIWithFlags",
+        "goHome", "homePage", "gotoIndex", "currentURI", "documentURI",
+        "preferences", "imageDocument", "isRemoteBrowser", "messageManager",
+        "getTabBrowser", "finder", "fastFind", "sessionHistory", "contentTitle",
+        "characterSet", "fullZoom", "textZoom", "webProgress",
+        "addProgressListener", "removeProgressListener", "audioPlaybackStarted",
+        "audioPlaybackStopped", "adjustPriority", "pauseMedia", "stopMedia",
+        "blockMedia", "resumeMedia", "audioMuted", "mute", "unmute",
+        "blockedPopups", "mIconURL", "lastURI", "userTypedValue",
+        "purgeSessionHistory", "stopScroll", "startScroll"
+      ]</field>
+
+      <method name="_createLazyBrowser">
+        <parameter name="aTab"/>
+        <body>
+          <![CDATA[
+            let browser = aTab.linkedBrowser;
+
+            let names = this._browserBindingProperties;
+
+            for (let i = 0; i < names.length; i++) {
+              let name = names[i];
+              let getter;
+              let setter;
+              switch (name) {
+                default:
+                  getter = () => {
+                    this._insertBrowser(aTab);
+                    return browser[name];
+                  };
+                  setter = (value) => {
+                    this._insertBrowser(aTab);
+                    return browser[name] = value;
+                  };
+              }
+              Object.defineProperty(browser, name, {
+                get: getter,
+                set: setter,
+                configurable: true,
+                enumerable: true
+              });
+            }
+          ]]>
+        </body>
+      </method>
+
+      <method name="_insertBrowser">
         <parameter name="aTab"/>
-        <parameter name="aURI"/>
-        <parameter name="aParams"/>
         <body>
           <![CDATA[
             "use strict";
 
-            // Supported parameters:
-            // forceNotRemote, preferredRemoteType, userContextId, isPrerendered
+            // If browser is already inserted, or aTab doesn't have a
+            // browser, don't do anything.
+            if (aTab.linkedPanel || !aTab.linkedBrowser) {
+              return;
+            }
 
-            let uriIsAboutBlank = !aURI || aURI == "about:blank";
+            let browser = aTab.linkedBrowser;
 
-            let remoteType =
-              aParams.forceNotRemote ? E10SUtils.NOT_REMOTE
-              : E10SUtils.getRemoteTypeForURI(aURI, gMultiProcessBrowser,
-                                              aParams.preferredRemoteType);
-
-            let browser;
-            let usingPreloadedContent = false;
-
-            // If we open a new tab with the newtab URL in the default
-            // userContext, check if there is a preloaded browser ready.
-            // Private windows are not included because both the label and the
-            // icon for the tab would be set incorrectly (see bug 1195981).
-            if (aURI == BROWSER_NEW_TAB_URL &&
-                !aParams.userContextId &&
-                !PrivateBrowsingUtils.isWindowPrivate(window)) {
-              browser = this._getPreloadedBrowser();
-              if (browser) {
-                usingPreloadedContent = true;
-                aTab.permanentKey = browser.permanentKey;
+            // If browser is a lazy browser, delete the substitute properties.
+            if (this._browserBindingProperties[0] in browser) {
+              for (let name of this._browserBindingProperties) {
+                delete browser[name];
               }
             }
 
-            if (!browser) {
-              // No preloaded browser found, create one.
-              browser = this._createBrowser({permanentKey: aTab.permanentKey,
-                                             remoteType,
-                                             uriIsAboutBlank,
-                                             userContextId: aParams.userContextId,
-                                             sameProcessAsFrameLoader: aParams.sameProcessAsFrameLoader,
-                                             opener: aParams.opener,
-                                             isPrerendered: aParams.isPrerendered});
-            }
+            let { uriIsAboutBlank, remoteType, usingPreloadedContent } =
+                    aTab._browserParams;
+            delete aTab._browserParams;
 
             let notificationbox = this.getNotificationBox(browser);
             let uniqueId = this._generateUniquePanelID();
             notificationbox.id = uniqueId;
             aTab.linkedPanel = uniqueId;
-            aTab.linkedBrowser = browser;
-            aTab.hasBrowser = true;
-            this._tabForBrowser.set(browser, aTab);
 
             // Inject the <browser> into the DOM if necessary.
             if (!notificationbox.parentNode) {
@@ -2124,8 +2165,6 @@
 
             var evt = new CustomEvent("TabBrowserInserted", { bubbles: true, detail: {} });
             aTab.dispatchEvent(evt);
-
-            return { usingPreloadedContent };
           ]]>
         </body>
       </method>
@@ -2158,6 +2197,7 @@
             var aOriginPrincipal;
             var aDisallowInheritPrincipal;
             var aOpener;
+            var aForceBrowserInsertion;
             if (arguments.length == 2 &&
                 typeof arguments[1] == "object" &&
                 !(arguments[1] instanceof Ci.nsIURI)) {
@@ -2183,6 +2223,7 @@
               aDisallowInheritPrincipal = params.disallowInheritPrincipal;
               aOpener                   = params.opener;
               aIsPrerendered            = params.isPrerendered;
+              aForceBrowserInsertion    = params.forceBrowserInsertion;
             }
 
             // if we're adding tabs, we're past interrupt mode, ditch the owner
@@ -2245,7 +2286,6 @@
 
             var position = this.tabs.length - 1;
             t._tPos = position;
-            t.permanentKey = {};
             this.tabContainer._setPositionalAttributes();
 
             this.tabContainer.updateVisibility();
@@ -2259,23 +2299,51 @@
                                               gMultiProcessBrowser);
             }
 
-            // Currently in this incarnation of bug 906076, we are forcing the
-            // browser to immediately be linked.  In future incarnations of this
-            // bug this will be removed so we can leave the tab in its "lazy"
-            // state to be exploited for startup optimization.  Note that for
-            // now this must occur before "TabOpen" event is fired, as that will
-            // trigger SessionStore.jsm to run code that expects the existence
-            // of tab.linkedBrowser.
-            let browserParams = {
-              forceNotRemote: aForceNotRemote,
-              preferredRemoteType: aPreferredRemoteType,
-              userContextId:  aUserContextId,
-              sameProcessAsFrameLoader: aSameProcessAsFrameLoader,
-              opener: aOpener,
-              isPrerendered: aIsPrerendered,
-            };
-            let { usingPreloadedContent } = this._linkBrowserToTab(t, aURI, browserParams);
-            let b = t.linkedBrowser;
+            let remoteType =
+              aForceNotRemote ? E10SUtils.NOT_REMOTE
+              : E10SUtils.getRemoteTypeForURI(aURI, gMultiProcessBrowser,
+                                              aPreferredRemoteType);
+
+            let b;
+            let usingPreloadedContent = false;
+
+            // If we open a new tab with the newtab URL in the default
+            // userContext, check if there is a preloaded browser ready.
+            // Private windows are not included because both the label and the
+            // icon for the tab would be set incorrectly (see bug 1195981).
+            if (aURI == BROWSER_NEW_TAB_URL &&
+                !aUserContextId &&
+                !PrivateBrowsingUtils.isWindowPrivate(window)) {
+              b = this._getPreloadedBrowser();
+              if (b) {
+                usingPreloadedContent = true;
+              }
+            }
+
+            if (!b) {
+              // No preloaded browser found, create one.
+              b = this._createBrowser({ remoteType,
+                                        uriIsAboutBlank,
+                                        userContextId: aUserContextId,
+                                        sameProcessAsFrameLoader: aSameProcessAsFrameLoader,
+                                        opener: aOpener,
+                                        isPrerendered: aIsPrerendered });
+            }
+
+            t.linkedBrowser = b;
+            this._tabForBrowser.set(b, t);
+            t.permanentKey = b.permanentKey;
+            t._browserParams = { uriIsAboutBlank,
+                                 remoteType,
+                                 usingPreloadedContent };
+
+            // If we're creating a blank tab, create a lazy browser.
+            // Otherwise insert the browser into the document now.
+            if (uriIsAboutBlank && !aForceBrowserInsertion) {
+              this._createLazyBrowser(t);
+            } else {
+              this._insertBrowser(t);
+            }
 
             // Dispatch a new tab notification.  We do this once we're
             // entirely done, so that things are in a consistent state
@@ -2495,6 +2563,9 @@
               var skipPermitUnload = aParams.skipPermitUnload;
             }
 
+            // Ensure aTab's browser is inserted into the document.
+            this._insertBrowser(aTab);
+
             window.maybeRecordAbandonmentTelemetry(aTab, "tabClosed");
 
             // Handle requests for synchronously removing an already
@@ -2994,6 +3065,9 @@
         <parameter name="aStateFlags"/>
         <body>
           <![CDATA[
+            // aOurTab's browser needs to be inserted now if it hasn't already.
+            this._insertBrowser(aOurTab);
+
             // Unhook our progress listener
             const filter = this._tabFilters.get(aOurTab);
             let tabListener = this._tabListeners.get(aOurTab);
@@ -4966,7 +5040,6 @@
           this.mCurrentTab._fullyOpen = true;
           this.mCurrentTab.cachePosition = 0;
           this.mCurrentTab.linkedBrowser = this.mCurrentBrowser;
-          this.mCurrentTab.hasBrowser = true;
           this._tabForBrowser.set(this.mCurrentBrowser, this.mCurrentTab);
 
           // set up the shared autoscroll popup
@@ -6282,6 +6355,21 @@
         </body>
       </method>
 
+      <method name="getRelatedElement">
+        <parameter name="aTab"/>
+        <body>
+        <![CDATA[
+          if (!aTab)
+            return null;
+          // If the tab's browser is lazy, we need to `_insertBrowser` in order
+          // to have a linkedPanel.  This will also serve to bind the browser
+          // and make it ready to use when the tab is selected.
+          this.tabbrowser._insertBrowser(aTab);
+          return document.getElementById(aTab.linkedPanel);
+        ]]>
+        </body>
+      </method>
+
       <!-- Deprecated stuff, implemented for backwards compatibility. -->
       <property name="mAllTabsPopup" readonly="true"
                 onget="return document.getElementById('alltabs-popup');"/>
diff --git a/browser/extensions/pdfjs/README.mozilla b/browser/extensions/pdfjs/README.mozilla
index 975b06fbe425..da0e38f01d95 100644
--- a/browser/extensions/pdfjs/README.mozilla
+++ b/browser/extensions/pdfjs/README.mozilla
@@ -1,3 +1,3 @@
 This is the pdf.js project output, https://github.com/mozilla/pdf.js
 
-Current extension version is: 1.7.297
+Current extension version is: 1.7.312
diff --git a/browser/extensions/pdfjs/content/build/pdf.js b/browser/extensions/pdfjs/content/build/pdf.js
index 20b137d2ddd5..4b0b7fd115a5 100644
--- a/browser/extensions/pdfjs/content/build/pdf.js
+++ b/browser/extensions/pdfjs/content/build/pdf.js
@@ -221,6 +221,11 @@ var VERBOSITY_LEVELS = {
  warnings: 1,
  infos: 5
 };
+var CMapCompressionType = {
+ NONE: 0,
+ BINARY: 1,
+ STREAM: 2
+};
 var OPS = {
  dependency: 1,
  setLineWidth: 2,
@@ -1166,6 +1171,12 @@ function isArrayBuffer(v) {
 function isSpace(ch) {
  return ch === 0x20 || ch === 0x09 || ch === 0x0D || ch === 0x0A;
 }
+function isNodeJS() {
+ if (typeof __pdfjsdev_webpack__ === 'undefined') {
+  return typeof process === 'object' && process + '' === '[object process]';
+ }
+ return false;
+}
 function createPromiseCapability() {
  var capability = {};
  capability.promise = new Promise(function (resolve, reject) {
@@ -1438,6 +1449,7 @@ exports.AnnotationFlag = AnnotationFlag;
 exports.AnnotationType = AnnotationType;
 exports.FontType = FontType;
 exports.ImageKind = ImageKind;
+exports.CMapCompressionType = CMapCompressionType;
 exports.InvalidPDFException = InvalidPDFException;
 exports.MessageHandler = MessageHandler;
 exports.MissingDataException = MissingDataException;
@@ -1474,6 +1486,7 @@ exports.isInt = isInt;
 exports.isNum = isNum;
 exports.isString = isString;
 exports.isSpace = isSpace;
+exports.isNodeJS = isNodeJS;
 exports.isSameOrigin = isSameOrigin;
 exports.createValidAbsoluteUrl = createValidAbsoluteUrl;
 exports.isLittleEndian = isLittleEndian;
@@ -1506,6 +1519,8 @@ var removeNullCharacters = sharedUtil.removeNullCharacters;
 var warn = sharedUtil.warn;
 var deprecated = sharedUtil.deprecated;
 var createValidAbsoluteUrl = sharedUtil.createValidAbsoluteUrl;
+var stringToBytes = sharedUtil.stringToBytes;
+var CMapCompressionType = sharedUtil.CMapCompressionType;
 var DEFAULT_LINK_REL = 'noopener noreferrer nofollow';
 function DOMCanvasFactory() {
 }
@@ -1535,6 +1550,48 @@ DOMCanvasFactory.prototype = {
   canvasAndContextPair.context = null;
  }
 };
+var DOMCMapReaderFactory = function DOMCMapReaderFactoryClosure() {
+ function DOMCMapReaderFactory(params) {
+  this.baseUrl = params.baseUrl || null;
+  this.isCompressed = params.isCompressed || false;
+ }
+ DOMCMapReaderFactory.prototype = {
+  fetch: function (params) {
+   if (!params.name) {
+    return Promise.reject(new Error('CMap name must be specified.'));
+   }
+   return new Promise(function (resolve, reject) {
+    var url = this.baseUrl + params.name;
+    var request = new XMLHttpRequest();
+    if (this.isCompressed) {
+     url += '.bcmap';
+     request.responseType = 'arraybuffer';
+    }
+    request.onreadystatechange = function () {
+     if (request.readyState === XMLHttpRequest.DONE && (request.status === 200 || request.status === 0)) {
+      var data;
+      if (this.isCompressed && request.response) {
+       data = new Uint8Array(request.response);
+      } else if (!this.isCompressed && request.responseText) {
+       data = stringToBytes(request.responseText);
+      }
+      if (data) {
+       resolve({
+        cMapData: data,
+        compressionType: this.isCompressed ? CMapCompressionType.BINARY : CMapCompressionType.NONE
+       });
+       return;
+      }
+      reject(new Error('Unable to load ' + (this.isCompressed ? 'binary' : '') + ' CMap at: ' + url));
+     }
+    }.bind(this);
+    request.open('GET', url, true);
+    request.send(null);
+   }.bind(this));
+  }
+ };
+ return DOMCMapReaderFactory;
+}();
 var CustomStyle = function CustomStyleClosure() {
  var prefixes = [
   'ms',
@@ -1694,6 +1751,7 @@ exports.hasCanvasTypedArrays = hasCanvasTypedArrays;
 exports.getDefaultSetting = getDefaultSetting;
 exports.DEFAULT_LINK_REL = DEFAULT_LINK_REL;
 exports.DOMCanvasFactory = DOMCanvasFactory;
+exports.DOMCMapReaderFactory = DOMCMapReaderFactory;
 
 /***/ }),
 /* 2 */
@@ -2358,6 +2416,7 @@ var CanvasGraphics = displayCanvas.CanvasGraphics;
 var Metadata = displayMetadata.Metadata;
 var getDefaultSetting = displayDOMUtils.getDefaultSetting;
 var DOMCanvasFactory = displayDOMUtils.DOMCanvasFactory;
+var DOMCMapReaderFactory = displayDOMUtils.DOMCMapReaderFactory;
 var DEFAULT_RANGE_CHUNK_SIZE = 65536;
 var isWorkerDisabled = false;
 var workerSrc;
@@ -2431,6 +2490,7 @@ function getDocument(src, pdfDataRangeTransport, passwordCallback, progressCallb
  }
  params.rangeChunkSize = params.rangeChunkSize || DEFAULT_RANGE_CHUNK_SIZE;
  params.disableNativeImageDecoder = params.disableNativeImageDecoder === true;
+ var CMapReaderFactory = params.CMapReaderFactory || DOMCMapReaderFactory;
  if (!worker) {
   worker = new PDFWorker();
   task._worker = worker;
@@ -2445,7 +2505,7 @@ function getDocument(src, pdfDataRangeTransport, passwordCallback, progressCallb
     throw new Error('Loading aborted');
    }
    var messageHandler = new MessageHandler(docId, workerId, worker.port);
-   var transport = new WorkerTransport(messageHandler, task, rangeTransport);
+   var transport = new WorkerTransport(messageHandler, task, rangeTransport, CMapReaderFactory);
    task._transport = transport;
    messageHandler.send('Ready', null);
   });
@@ -2468,8 +2528,6 @@ function _fetchDocument(worker, source, pdfDataRangeTransport, docId) {
   source: source,
   disableRange: getDefaultSetting('disableRange'),
   maxImageSize: getDefaultSetting('maxImageSize'),
-  cMapUrl: getDefaultSetting('cMapUrl'),
-  cMapPacked: getDefaultSetting('cMapPacked'),
   disableFontFace: getDefaultSetting('disableFontFace'),
   disableCreateObjectURL: getDefaultSetting('disableCreateObjectURL'),
   postMessageTransfers: getDefaultSetting('postMessageTransfers') && !isPostMessageTransfersDisabled,
@@ -3081,12 +3139,16 @@ var PDFWorker = function PDFWorkerClosure() {
  return PDFWorker;
 }();
 var WorkerTransport = function WorkerTransportClosure() {
- function WorkerTransport(messageHandler, loadingTask, pdfDataRangeTransport) {
+ function WorkerTransport(messageHandler, loadingTask, pdfDataRangeTransport, CMapReaderFactory) {
   this.messageHandler = messageHandler;
   this.loadingTask = loadingTask;
   this.pdfDataRangeTransport = pdfDataRangeTransport;
   this.commonObjs = new PDFObjects();
   this.fontLoader = new FontLoader(loadingTask.docId);
+  this.CMapReaderFactory = new CMapReaderFactory({
+   baseUrl: getDefaultSetting('cMapUrl'),
+   isCompressed: getDefaultSetting('cMapPacked')
+  });
   this.destroyed = false;
   this.destroyCapability = null;
   this._passwordCapability = null;
@@ -3371,6 +3433,12 @@ var WorkerTransport = function WorkerTransportClosure() {
      img.src = imageUrl;
     });
    }, this);
+   messageHandler.on('FetchBuiltInCMap', function (data) {
+    if (this.destroyed) {
+     return Promise.reject(new Error('Worker was destroyed'));
+    }
+    return this.CMapReaderFactory.fetch({ name: data.name });
+   }, this);
   },
   getData: function WorkerTransport_getData() {
    return this.messageHandler.sendWithPromise('GetData', null);
@@ -3632,8 +3700,8 @@ var _UnsupportedManager = function UnsupportedManagerClosure() {
   }
  };
 }();
-exports.version = '1.7.297';
-exports.build = '425ad309';
+exports.version = '1.7.312';
+exports.build = 'cada411a';
 exports.getDocument = getDocument;
 exports.PDFDataRangeTransport = PDFDataRangeTransport;
 exports.PDFWorker = PDFWorker;
@@ -4650,8 +4718,8 @@ if (!globalScope.PDFJS) {
  globalScope.PDFJS = {};
 }
 var PDFJS = globalScope.PDFJS;
-PDFJS.version = '1.7.297';
-PDFJS.build = '425ad309';
+PDFJS.version = '1.7.312';
+PDFJS.build = 'cada411a';
 PDFJS.pdfBug = false;
 if (PDFJS.verbosity !== undefined) {
  sharedUtil.setVerbosityLevel(PDFJS.verbosity);
@@ -7143,8 +7211,8 @@ exports.TilingPattern = TilingPattern;
 
 "use strict";
 
-var pdfjsVersion = '1.7.297';
-var pdfjsBuild = '425ad309';
+var pdfjsVersion = '1.7.312';
+var pdfjsBuild = 'cada411a';
 var pdfjsSharedUtil = __w_pdfjs_require__(0);
 var pdfjsDisplayGlobal = __w_pdfjs_require__(8);
 var pdfjsDisplayAPI = __w_pdfjs_require__(3);
diff --git a/browser/extensions/pdfjs/content/build/pdf.worker.js b/browser/extensions/pdfjs/content/build/pdf.worker.js
index 63170673249f..8c47f3c4b461 100644
--- a/browser/extensions/pdfjs/content/build/pdf.worker.js
+++ b/browser/extensions/pdfjs/content/build/pdf.worker.js
@@ -221,6 +221,11 @@ var VERBOSITY_LEVELS = {
  warnings: 1,
  infos: 5
 };
+var CMapCompressionType = {
+ NONE: 0,
+ BINARY: 1,
+ STREAM: 2
+};
 var OPS = {
  dependency: 1,
  setLineWidth: 2,
@@ -1166,6 +1171,12 @@ function isArrayBuffer(v) {
 function isSpace(ch) {
  return ch === 0x20 || ch === 0x09 || ch === 0x0D || ch === 0x0A;
 }
+function isNodeJS() {
+ if (typeof __pdfjsdev_webpack__ === 'undefined') {
+  return typeof process === 'object' && process + '' === '[object process]';
+ }
+ return false;
+}
 function createPromiseCapability() {
  var capability = {};
  capability.promise = new Promise(function (resolve, reject) {
@@ -1438,6 +1449,7 @@ exports.AnnotationFlag = AnnotationFlag;
 exports.AnnotationType = AnnotationType;
 exports.FontType = FontType;
 exports.ImageKind = ImageKind;
+exports.CMapCompressionType = CMapCompressionType;
 exports.InvalidPDFException = InvalidPDFException;
 exports.MessageHandler = MessageHandler;
 exports.MissingDataException = MissingDataException;
@@ -1474,6 +1486,7 @@ exports.isInt = isInt;
 exports.isNum = isNum;
 exports.isString = isString;
 exports.isSpace = isSpace;
+exports.isNodeJS = isNodeJS;
 exports.isSameOrigin = isSameOrigin;
 exports.createValidAbsoluteUrl = createValidAbsoluteUrl;
 exports.isLittleEndian = isLittleEndian;
@@ -24787,6 +24800,7 @@ var UNSUPPORTED_FEATURES = sharedUtil.UNSUPPORTED_FEATURES;
 var ImageKind = sharedUtil.ImageKind;
 var OPS = sharedUtil.OPS;
 var TextRenderingMode = sharedUtil.TextRenderingMode;
+var CMapCompressionType = sharedUtil.CMapCompressionType;
 var Util = sharedUtil.Util;
 var assert = sharedUtil.assert;
 var createPromiseCapability = sharedUtil.createPromiseCapability;
@@ -24845,10 +24859,6 @@ var PartialEvaluator = function PartialEvaluatorClosure() {
   forceDataSchema: false,
   maxImageSize: -1,
   disableFontFace: false,
-  cMapOptions: {
-   url: null,
-   packed: false
-  },
   disableNativeImageDecoder: false
  };
  function NativeImageDecoder(xref, resources, handler, forceDataSchema) {
@@ -24892,14 +24902,27 @@ var PartialEvaluator = function PartialEvaluatorClosure() {
   var cs = ColorSpace.parse(dict.get('ColorSpace', 'CS'), xref, res);
   return (cs.numComps === 1 || cs.numComps === 3) && cs.isDefaultDecode(dict.getArray('Decode', 'D'));
  };
- function PartialEvaluator(pdfManager, xref, handler, pageIndex, idFactory, fontCache, options) {
+ function PartialEvaluator(pdfManager, xref, handler, pageIndex, idFactory, fontCache, builtInCMapCache, options) {
   this.pdfManager = pdfManager;
   this.xref = xref;
   this.handler = handler;
   this.pageIndex = pageIndex;
   this.idFactory = idFactory;
   this.fontCache = fontCache;
+  this.builtInCMapCache = builtInCMapCache;
   this.options = options || DefaultPartialEvaluatorOptions;
+  this.fetchBuiltInCMap = function (name) {
+   var cachedCMap = builtInCMapCache[name];
+   if (cachedCMap) {
+    return Promise.resolve(cachedCMap);
+   }
+   return handler.sendWithPromise('FetchBuiltInCMap', { name: name }).then(function (data) {
+    if (data.compressionType !== CMapCompressionType.NONE) {
+     builtInCMapCache[name] = data;
+    }
+    return data;
+   });
+  };
  }
  var TIME_SLOT_DURATION_MS = 20;
  var CHECK_TIME_EVERY = 100;
@@ -26236,7 +26259,11 @@ var PartialEvaluator = function PartialEvaluatorClosure() {
     var registry = properties.cidSystemInfo.registry;
     var ordering = properties.cidSystemInfo.ordering;
     var ucs2CMapName = Name.get(registry + '-' + ordering + '-UCS2');
-    return CMapFactory.create(ucs2CMapName, this.options.cMapOptions, null).then(function (ucs2CMap) {
+    return CMapFactory.create({
+     encoding: ucs2CMapName,
+     fetchBuiltInCMap: this.fetchBuiltInCMap,
+     useCMap: null
+    }).then(function (ucs2CMap) {
      var cMap = properties.cMap;
      toUnicode = [];
      cMap.forEach(function (charcode, cid) {
@@ -26254,14 +26281,22 @@ var PartialEvaluator = function PartialEvaluatorClosure() {
   readToUnicode: function PartialEvaluator_readToUnicode(toUnicode) {
    var cmapObj = toUnicode;
    if (isName(cmapObj)) {
-    return CMapFactory.create(cmapObj, this.options.cMapOptions, null).then(function (cmap) {
+    return CMapFactory.create({
+     encoding: cmapObj,
+     fetchBuiltInCMap: this.fetchBuiltInCMap,
+     useCMap: null
+    }).then(function (cmap) {
      if (cmap instanceof IdentityCMap) {
       return new IdentityToUnicodeMap(0, 0xFFFF);
      }
      return new ToUnicodeMap(cmap.getMap());
     });
    } else if (isStream(cmapObj)) {
-    return CMapFactory.create(cmapObj, this.options.cMapOptions, null).then(function (cmap) {
+    return CMapFactory.create({
+     encoding: cmapObj,
+     fetchBuiltInCMap: this.fetchBuiltInCMap,
+     useCMap: null
+    }).then(function (cmap) {
      if (cmap instanceof IdentityCMap) {
       return new IdentityToUnicodeMap(0, 0xFFFF);
      }
@@ -26524,7 +26559,6 @@ var PartialEvaluator = function PartialEvaluatorClosure() {
    var descriptor = preEvaluatedFont.descriptor;
    var type = preEvaluatedFont.type;
    var maxCharIndex = composite ? 0xFFFF : 0xFF;
-   var cMapOptions = this.options.cMapOptions;
    var properties;
    if (!descriptor) {
     if (type === 'Type3') {
@@ -26619,7 +26653,11 @@ var PartialEvaluator = function PartialEvaluatorClosure() {
     if (isName(cidEncoding)) {
      properties.cidEncoding = cidEncoding.name;
     }
-    cMapPromise = CMapFactory.create(cidEncoding, cMapOptions, null).then(function (cMap) {
+    cMapPromise = CMapFactory.create({
+     encoding: cidEncoding,
+     fetchBuiltInCMap: this.fetchBuiltInCMap,
+     useCMap: null
+    }).then(function (cMap) {
      properties.cMap = cMap;
      properties.vertical = properties.cMap.vertical;
     });
@@ -29872,6 +29910,7 @@ var Catalog = function CatalogClosure() {
   this.xref = xref;
   this.catDict = xref.getCatalogObj();
   this.fontCache = new RefSetCache();
+  this.builtInCMapCache = Object.create(null);
   assert(isDict(this.catDict), 'catalog object is not a dictionary');
   this.pageFactory = pageFactory;
   this.pagePromises = [];
@@ -30186,6 +30225,7 @@ var Catalog = function CatalogClosure() {
      delete font.translated;
     }
     this.fontCache.clear();
+    this.builtInCMapCache = Object.create(null);
    }.bind(this));
   },
   getPage: function Catalog_getPage(pageIndex) {
@@ -30193,7 +30233,7 @@ var Catalog = function CatalogClosure() {
     this.pagePromises[pageIndex] = this.getPageDict(pageIndex).then(function (a) {
      var dict = a[0];
      var ref = a[1];
-     return this.pageFactory.createPage(pageIndex, dict, ref, this.fontCache);
+     return this.pageFactory.createPage(pageIndex, dict, ref, this.fontCache, this.builtInCMapCache);
     }.bind(this));
    }
    return this.pagePromises[pageIndex];
@@ -33926,6 +33966,7 @@ var error = sharedUtil.error;
 var info = sharedUtil.info;
 var warn = sharedUtil.warn;
 var setVerbosityLevel = sharedUtil.setVerbosityLevel;
+var isNodeJS = sharedUtil.isNodeJS;
 var Ref = corePrimitives.Ref;
 var LocalPdfManager = corePdfManager.LocalPdfManager;
 var NetworkPdfManager = corePdfManager.NetworkPdfManager;
@@ -34403,15 +34444,10 @@ var WorkerMessageHandler = {
     }, onFailure);
    }
    ensureNotTerminated();
-   var cMapOptions = {
-    url: data.cMapUrl === undefined ? null : data.cMapUrl,
-    packed: data.cMapPacked === true
-   };
    var evaluatorOptions = {
     forceDataSchema: data.disableCreateObjectURL,
     maxImageSize: data.maxImageSize === undefined ? -1 : data.maxImageSize,
     disableFontFace: data.disableFontFace,
-    cMapOptions: cMapOptions,
     disableNativeImageDecoder: data.disableNativeImageDecoder
    };
    getPdfManager(data, evaluatorOptions).then(function (newPdfManager) {
@@ -34588,12 +34624,6 @@ function initializeWorker() {
  WorkerMessageHandler.setup(handler, self);
  handler.send('ready', null);
 }
-function isNodeJS() {
- if (typeof __pdfjsdev_webpack__ === 'undefined') {
-  return typeof process === 'object' && process + '' === '[object process]';
- }
- return false;
-}
 if (typeof window === 'undefined' && !isNodeJS()) {
  initializeWorker();
 }
@@ -36580,11 +36610,12 @@ var error = sharedUtil.error;
 var isInt = sharedUtil.isInt;
 var isString = sharedUtil.isString;
 var MissingDataException = sharedUtil.MissingDataException;
+var CMapCompressionType = sharedUtil.CMapCompressionType;
 var isEOF = corePrimitives.isEOF;
 var isName = corePrimitives.isName;
 var isCmd = corePrimitives.isCmd;
 var isStream = corePrimitives.isStream;
-var StringStream = coreStream.StringStream;
+var Stream = coreStream.Stream;
 var Lexer = coreParser.Lexer;
 var BUILT_IN_CMAPS = [
  'Adobe-GB1-UCS2',
@@ -36919,23 +36950,6 @@ var IdentityCMap = function IdentityCMapClosure() {
  return IdentityCMap;
 }();
 var BinaryCMapReader = function BinaryCMapReaderClosure() {
- function fetchBinaryData(url) {
-  return new Promise(function (resolve, reject) {
-   var request = new XMLHttpRequest();
-   request.open('GET', url, true);
-   request.responseType = 'arraybuffer';
-   request.onreadystatechange = function () {
-    if (request.readyState === XMLHttpRequest.DONE) {
-     if (!request.response || request.status !== 200 && request.status !== 0) {
-      reject(new Error('Unable to get binary cMap at: ' + url));
-     } else {
-      resolve(new Uint8Array(request.response));
-     }
-    }
-   };
-   request.send(null);
-  });
- }
  function hexToInt(a, size) {
   var n = 0;
   for (var i = 0; i <= size; i++) {
@@ -37045,8 +37059,8 @@ var BinaryCMapReader = function BinaryCMapReaderClosure() {
    return s;
   }
  };
- function processBinaryCMap(url, cMap, extend) {
-  return fetchBinaryData(url).then(function (data) {
+ function processBinaryCMap(data, cMap, extend) {
+  return new Promise(function (resolve, reject) {
    var stream = new BinaryCMapStream(data);
    var header = stream.readByte();
    cMap.vertical = !!(header & 1);
@@ -37177,19 +37191,20 @@ var BinaryCMapReader = function BinaryCMapReaderClosure() {
      }
      break;
     default:
-     error('Unknown type: ' + type);
-     break;
+     reject(new Error('processBinaryCMap: Unknown type: ' + type));
+     return;
     }
    }
    if (useCMap) {
-    return extend(useCMap);
+    resolve(extend(useCMap));
+    return;
    }
-   return cMap;
+   resolve(cMap);
   });
  }
  function BinaryCMapReader() {
  }
- BinaryCMapReader.prototype = { read: processBinaryCMap };
+ BinaryCMapReader.prototype = { process: processBinaryCMap };
  return BinaryCMapReader;
 }();
 var CMapFactory = function CMapFactoryClosure() {
@@ -37330,7 +37345,7 @@ var CMapFactory = function CMapFactoryClosure() {
    cMap.name = obj.name;
   }
  }
- function parseCMap(cMap, lexer, builtInCMapParams, useCMap) {
+ function parseCMap(cMap, lexer, fetchBuiltInCMap, useCMap) {
   var previous;
   var embededUseCMap;
   objLoop:
@@ -37384,12 +37399,12 @@ var CMapFactory = function CMapFactoryClosure() {
    useCMap = embededUseCMap;
   }
   if (useCMap) {
-   return extendCMap(cMap, builtInCMapParams, useCMap);
+   return extendCMap(cMap, fetchBuiltInCMap, useCMap);
   }
   return Promise.resolve(cMap);
  }
- function extendCMap(cMap, builtInCMapParams, useCMap) {
-  return createBuiltInCMap(useCMap, builtInCMapParams).then(function (newCMap) {
+ function extendCMap(cMap, fetchBuiltInCMap, useCMap) {
+  return createBuiltInCMap(useCMap, fetchBuiltInCMap).then(function (newCMap) {
    cMap.useCMap = newCMap;
    if (cMap.numCodespaceRanges === 0) {
     var useCodespaceRanges = cMap.useCMap.codespaceRanges;
@@ -37406,14 +37421,7 @@ var CMapFactory = function CMapFactoryClosure() {
    return cMap;
   });
  }
- function parseBinaryCMap(name, builtInCMapParams) {
-  var url = builtInCMapParams.url + name + '.bcmap';
-  var cMap = new CMap(true);
-  return new BinaryCMapReader().read(url, cMap, function (useCMap) {
-   return extendCMap(cMap, builtInCMapParams, useCMap);
-  });
- }
- function createBuiltInCMap(name, builtInCMapParams) {
+ function createBuiltInCMap(name, fetchBuiltInCMap) {
   if (name === 'Identity-H') {
    return Promise.resolve(new IdentityCMap(false, 2));
   } else if (name === 'Identity-V') {
@@ -37422,40 +37430,33 @@ var CMapFactory = function CMapFactoryClosure() {
   if (BUILT_IN_CMAPS.indexOf(name) === -1) {
    return Promise.reject(new Error('Unknown cMap name: ' + name));
   }
-  assert(builtInCMapParams, 'built-in cMap parameters are not provided');
-  if (builtInCMapParams.packed) {
-   return parseBinaryCMap(name, builtInCMapParams);
-  }
-  return new Promise(function (resolve, reject) {
-   var url = builtInCMapParams.url + name;
-   var request = new XMLHttpRequest();
-   request.onreadystatechange = function () {
-    if (request.readyState === XMLHttpRequest.DONE) {
-     if (request.status === 200 || request.status === 0) {
-      var cMap = new CMap(true);
-      var lexer = new Lexer(new StringStream(request.responseText));
-      parseCMap(cMap, lexer, builtInCMapParams, null).then(function (parsedCMap) {
-       resolve(parsedCMap);
-      });
-     } else {
-      reject(new Error('Unable to get cMap at: ' + url));
-     }
-    }
-   };
-   request.open('GET', url, true);
-   request.send(null);
+  assert(fetchBuiltInCMap, 'Built-in CMap parameters are not provided.');
+  return fetchBuiltInCMap(name).then(function (data) {
+   var cMapData = data.cMapData, compressionType = data.compressionType;
+   var cMap = new CMap(true);
+   if (compressionType === CMapCompressionType.BINARY) {
+    return new BinaryCMapReader().process(cMapData, cMap, function (useCMap) {
+     return extendCMap(cMap, fetchBuiltInCMap, useCMap);
+    });
+   }
+   assert(compressionType === CMapCompressionType.NONE, 'TODO: Only BINARY/NONE CMap compression is currently supported.');
+   var lexer = new Lexer(new Stream(cMapData));
+   return parseCMap(cMap, lexer, fetchBuiltInCMap, null);
   });
  }
  return {
-  create: function (encoding, builtInCMapParams, useCMap) {
+  create: function (params) {
+   var encoding = params.encoding;
+   var fetchBuiltInCMap = params.fetchBuiltInCMap;
+   var useCMap = params.useCMap;
    if (isName(encoding)) {
-    return createBuiltInCMap(encoding.name, builtInCMapParams);
+    return createBuiltInCMap(encoding.name, fetchBuiltInCMap);
    } else if (isStream(encoding)) {
     var cMap = new CMap();
     var lexer = new Lexer(encoding);
-    return parseCMap(cMap, lexer, builtInCMapParams, useCMap).then(function (parsedCMap) {
+    return parseCMap(cMap, lexer, fetchBuiltInCMap, useCMap).then(function (parsedCMap) {
      if (parsedCMap.isIdentityCMap) {
-      return createBuiltInCMap(parsedCMap.name, builtInCMapParams);
+      return createBuiltInCMap(parsedCMap.name, fetchBuiltInCMap);
      }
      return parsedCMap;
     });
@@ -37520,13 +37521,14 @@ var Page = function PageClosure() {
   612,
   792
  ];
- function Page(pdfManager, xref, pageIndex, pageDict, ref, fontCache) {
+ function Page(pdfManager, xref, pageIndex, pageDict, ref, fontCache, builtInCMapCache) {
   this.pdfManager = pdfManager;
   this.pageIndex = pageIndex;
   this.pageDict = pageDict;
   this.xref = xref;
   this.ref = ref;
   this.fontCache = fontCache;
+  this.builtInCMapCache = builtInCMapCache;
   this.evaluatorOptions = pdfManager.evaluatorOptions;
   this.resourcesPromise = null;
   var uniquePrefix = 'p' + this.pageIndex + '_';
@@ -37652,7 +37654,7 @@ var Page = function PageClosure() {
     'XObject',
     'Font'
    ]);
-   var partialEvaluator = new PartialEvaluator(pdfManager, this.xref, handler, this.pageIndex, this.idFactory, this.fontCache, this.evaluatorOptions);
+   var partialEvaluator = new PartialEvaluator(pdfManager, this.xref, handler, this.pageIndex, this.idFactory, this.fontCache, this.builtInCMapCache, this.evaluatorOptions);
    var dataPromises = Promise.all([
     contentStreamPromise,
     resourcesPromise
@@ -37708,7 +37710,7 @@ var Page = function PageClosure() {
    ]);
    return dataPromises.then(function (data) {
     var contentStream = data[0];
-    var partialEvaluator = new PartialEvaluator(pdfManager, self.xref, handler, self.pageIndex, self.idFactory, self.fontCache, self.evaluatorOptions);
+    var partialEvaluator = new PartialEvaluator(pdfManager, self.xref, handler, self.pageIndex, self.idFactory, self.fontCache, self.builtInCMapCache, self.evaluatorOptions);
     return partialEvaluator.getTextContent(contentStream, task, self.resources, null, normalizeWhitespace, combineTextItems);
    });
   },
@@ -37901,8 +37903,8 @@ var PDFDocument = function PDFDocumentClosure() {
    this.xref.parse(recoveryMode);
    var self = this;
    var pageFactory = {
-    createPage: function (pageIndex, dict, ref, fontCache) {
-     return new Page(self.pdfManager, self.xref, pageIndex, dict, ref, fontCache);
+    createPage: function (pageIndex, dict, ref, fontCache, builtInCMapCache) {
+     return new Page(self.pdfManager, self.xref, pageIndex, dict, ref, fontCache, builtInCMapCache);
     }
    };
    this.catalog = new Catalog(this.pdfManager, this.xref, pageFactory);
@@ -49174,8 +49176,8 @@ exports.Type1Parser = Type1Parser;
 
 "use strict";
 
-var pdfjsVersion = '1.7.297';
-var pdfjsBuild = '425ad309';
+var pdfjsVersion = '1.7.312';
+var pdfjsBuild = 'cada411a';
 var pdfjsCoreWorker = __w_pdfjs_require__(17);
 ;
 exports.WorkerMessageHandler = pdfjsCoreWorker.WorkerMessageHandler;
diff --git a/browser/extensions/pdfjs/content/web/viewer.js b/browser/extensions/pdfjs/content/web/viewer.js
index e163c108658c..749355fed12c 100644
--- a/browser/extensions/pdfjs/content/web/viewer.js
+++ b/browser/extensions/pdfjs/content/web/viewer.js
@@ -321,8 +321,11 @@ function getVisibleElements(scrollEl, views, sortByVisibility) {
 function noContextMenuHandler(e) {
  e.preventDefault();
 }
-function getPDFFileNameFromURL(url) {
- var reURI = /^(?:([^:]+:)?\/\/[^\/]+)?([^?#]*)(\?[^#]*)?(#.*)?$/;
+function getPDFFileNameFromURL(url, defaultFilename) {
+ if (typeof defaultFilename === 'undefined') {
+  defaultFilename = 'document.pdf';
+ }
+ var reURI = /^(?:(?:[^:]+:)?\/\/[^\/]+)?([^?#]*)(\?[^#]*)?(#.*)?$/;
  var reFilename = /[^\/?#=]+\.pdf\b(?!.*\.pdf\b)/i;
  var splitURI = reURI.exec(url);
  var suggestedFilename = reFilename.exec(splitURI[1]) || reFilename.exec(splitURI[2]) || reFilename.exec(splitURI[3]);
@@ -335,7 +338,7 @@ function getPDFFileNameFromURL(url) {
    }
   }
  }
- return suggestedFilename || 'document.pdf';
+ return suggestedFilename || defaultFilename;
 }
 function normalizeWheelEventDelta(evt) {
  var delta = Math.sqrt(evt.deltaX * evt.deltaX + evt.deltaY * evt.deltaY);
@@ -1148,11 +1151,15 @@ var PDFViewerApplication = {
  setTitleUsingUrl: function pdfViewSetTitleUsingUrl(url) {
   this.url = url;
   this.baseUrl = url.split('#')[0];
-  try {
-   this.setTitle(decodeURIComponent(pdfjsLib.getFilenameFromUrl(url)) || url);
-  } catch (e) {
-   this.setTitle(url);
+  var title = getPDFFileNameFromURL(url, '');
+  if (!title) {
+   try {
+    title = decodeURIComponent(pdfjsLib.getFilenameFromUrl(url)) || url;
+   } catch (e) {
+    title = url;
+   }
   }
+  this.setTitle(title);
  },
  setTitle: function pdfViewSetTitle(title) {
   if (this.isViewerEmbedded) {
@@ -1251,7 +1258,7 @@ var PDFViewerApplication = {
    downloadManager.downloadUrl(url, filename);
   }
   var url = this.baseUrl;
-  var filename = getPDFFileNameFromURL(url);
+  var filename = getPDFFileNameFromURL(this.url);
   var downloadManager = this.downloadManager;
   downloadManager.onerror = function (err) {
    PDFViewerApplication.error('PDF failed to download.');
@@ -3896,6 +3903,18 @@ var PDFAttachmentViewer = function PDFAttachmentViewerClosure() {
    });
    this._renderedCapability.resolve();
   },
+  _bindPdfLink: function PDFAttachmentViewer_bindPdfLink(button, content, filename) {
+   var blobUrl;
+   button.onclick = function () {
+    if (!blobUrl) {
+     blobUrl = pdfjsLib.createObjectURL(content, 'application/pdf', pdfjsLib.PDFJS.disableCreateObjectURL);
+    }
+    var viewerUrl;
+    viewerUrl = blobUrl + '?' + encodeURIComponent(filename);
+    window.open(viewerUrl);
+    return false;
+   };
+  },
   _bindLink: function PDFAttachmentViewer_bindLink(button, content, filename) {
    button.onclick = function downloadFile(e) {
     this.downloadManager.downloadData(content, filename, '');
@@ -3922,11 +3941,16 @@ var PDFAttachmentViewer = function PDFAttachmentViewerClosure() {
    for (var i = 0; i < attachmentsCount; i++) {
     var item = attachments[names[i]];
     var filename = pdfjsLib.getFilenameFromUrl(item.filename);
+    filename = pdfjsLib.removeNullCharacters(filename);
     var div = document.createElement('div');
     div.className = 'attachmentsItem';
     var button = document.createElement('button');
-    this._bindLink(button, item.content, filename);
-    button.textContent = pdfjsLib.removeNullCharacters(filename);
+    button.textContent = filename;
+    if (/\.pdf$/i.test(filename)) {
+     this._bindPdfLink(button, item.content, filename);
+    } else {
+     this._bindLink(button, item.content, filename);
+    }
     div.appendChild(button);
     this.container.appendChild(div);
    }
diff --git a/build/templates.mozbuild b/build/templates.mozbuild
index 9b8500f659b5..89240b5c5276 100644
--- a/build/templates.mozbuild
+++ b/build/templates.mozbuild
@@ -61,7 +61,7 @@ def Library(name):
 
 
 @template
-def RustLibrary(name, features=None):
+def RustLibrary(name, features=None, target_dir=None):
     '''Template for Rust libraries.'''
     Library(name)
 
@@ -70,6 +70,9 @@ def RustLibrary(name, features=None):
     if features:
         RUST_LIBRARY_FEATURES = features
 
+    if target_dir:
+        RUST_LIBRARY_TARGET_DIR = target_dir
+
 
 @template
 def SharedLibrary(name):
diff --git a/caps/nsNullPrincipal.cpp b/caps/nsNullPrincipal.cpp
index e1555e4794e1..20d713890c18 100644
--- a/caps/nsNullPrincipal.cpp
+++ b/caps/nsNullPrincipal.cpp
@@ -166,25 +166,43 @@ nsNullPrincipal::Read(nsIObjectInputStream* aStream)
   // that the Init() method has already been invoked by the time we deserialize.
   // This is in contrast to nsPrincipal, which uses NS_GENERIC_FACTORY_CONSTRUCTOR,
   // in which case ::Read needs to invoke Init().
-  nsAutoCString suffix;
-  nsresult rv = aStream->ReadCString(suffix);
+
+  nsAutoCString spec;
+  nsresult rv = aStream->ReadCString(spec);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  bool ok = mOriginAttributes.PopulateFromSuffix(suffix);
+  nsCOMPtr<nsIURI> uri;
+  rv = NS_NewURI(getter_AddRefs(uri), spec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString suffix;
+  rv = aStream->ReadCString(suffix);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  OriginAttributes attrs;
+  bool ok = attrs.PopulateFromSuffix(suffix);
   NS_ENSURE_TRUE(ok, NS_ERROR_FAILURE);
 
-  return NS_OK;
+  return Init(attrs, uri);
 }
 
 NS_IMETHODIMP
 nsNullPrincipal::Write(nsIObjectOutputStream* aStream)
 {
+  NS_ENSURE_STATE(mURI);
+
+  nsAutoCString spec;
+  nsresult rv = mURI->GetSpec(spec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = aStream->WriteStringZ(spec.get());
+  NS_ENSURE_SUCCESS(rv, rv);
+
   nsAutoCString suffix;
   OriginAttributesRef().CreateSuffix(suffix);
 
-  nsresult rv = aStream->WriteStringZ(suffix.get());
+  rv = aStream->WriteStringZ(suffix.get());
   NS_ENSURE_SUCCESS(rv, rv);
 
   return NS_OK;
 }
-
diff --git a/config/rules.mk b/config/rules.mk
index 1f974406b220..9bb17a2a8908 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -936,7 +936,7 @@ rustflags_override = RUSTFLAGS='$(rustflags)'
 endif
 
 CARGO_BUILD = env $(rustflags_override) \
-	CARGO_TARGET_DIR=. \
+	CARGO_TARGET_DIR=$(CARGO_TARGET_DIR) \
 	RUSTC=$(RUSTC) \
 	MOZ_DIST=$(ABS_DIST) \
 	LIBCLANG_PATH=$(MOZ_LIBCLANG_PATH) \
diff --git a/devtools/client/inspector/layout/actions/box-model.js b/devtools/client/inspector/boxmodel/actions/box-model.js
similarity index 100%
rename from devtools/client/inspector/layout/actions/box-model.js
rename to devtools/client/inspector/boxmodel/actions/box-model.js
diff --git a/devtools/client/inspector/boxmodel/actions/index.js b/devtools/client/inspector/boxmodel/actions/index.js
new file mode 100644
index 000000000000..45758428e733
--- /dev/null
+++ b/devtools/client/inspector/boxmodel/actions/index.js
@@ -0,0 +1,14 @@
+/* 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 { createEnum } = require("devtools/client/shared/enum");
+
+createEnum([
+
+  // Update the layout state with the latest layout properties.
+  "UPDATE_LAYOUT",
+
+], module.exports);
diff --git a/devtools/client/inspector/boxmodel/actions/moz.build b/devtools/client/inspector/boxmodel/actions/moz.build
new file mode 100644
index 000000000000..2f98f6793d0c
--- /dev/null
+++ b/devtools/client/inspector/boxmodel/actions/moz.build
@@ -0,0 +1,10 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+DevToolsModules(
+    'box-model.js',
+    'index.js',
+)
diff --git a/devtools/client/inspector/boxmodel/box-model.js b/devtools/client/inspector/boxmodel/box-model.js
new file mode 100644
index 000000000000..0290d69af88a
--- /dev/null
+++ b/devtools/client/inspector/boxmodel/box-model.js
@@ -0,0 +1,301 @@
+/* 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 { Task } = require("devtools/shared/task");
+const { getCssProperties } = require("devtools/shared/fronts/css-properties");
+const { ReflowFront } = require("devtools/shared/fronts/reflow");
+
+const { InplaceEditor } = require("devtools/client/shared/inplace-editor");
+
+const { updateLayout } = require("./actions/box-model");
+
+const EditingSession = require("./utils/editing-session");
+
+const NUMERIC = /^-?[\d\.]+$/;
+
+/**
+ * A singleton instance of the box model controllers.
+ *
+ * @param  {Inspector} inspector
+ *         An instance of the Inspector currently loaded in the toolbox.
+ * @param  {Window} window
+ *         The document window of the toolbox.
+ */
+function BoxModel(inspector, window) {
+  this.document = window.document;
+  this.inspector = inspector;
+  this.store = inspector.store;
+
+  this.updateBoxModel = this.updateBoxModel.bind(this);
+
+  this.onHideBoxModelHighlighter = this.onHideBoxModelHighlighter.bind(this);
+  this.onNewSelection = this.onNewSelection.bind(this);
+  this.onShowBoxModelEditor = this.onShowBoxModelEditor.bind(this);
+  this.onShowBoxModelHighlighter = this.onShowBoxModelHighlighter.bind(this);
+  this.onSidebarSelect = this.onSidebarSelect.bind(this);
+
+  this.inspector.selection.on("new-node-front", this.onNewSelection);
+  this.inspector.sidebar.on("select", this.onSidebarSelect);
+}
+
+BoxModel.prototype = {
+
+  /**
+   * Destruction function called when the inspector is destroyed. Removes event listeners
+   * and cleans up references.
+   */
+  destroy() {
+    this.inspector.selection.off("new-node-front", this.onNewSelection);
+    this.inspector.sidebar.off("select", this.onSidebarSelect);
+
+    if (this.reflowFront) {
+      this.untrackReflows();
+      this.reflowFront.destroy();
+      this.reflowFront = null;
+    }
+
+    this.document = null;
+    this.inspector = null;
+    this.walker = null;
+  },
+
+  /**
+   * Returns an object containing the box model's handler functions used in the box
+   * model's React component props.
+   */
+  getComponentProps() {
+    return {
+      onHideBoxModelHighlighter: this.onHideBoxModelHighlighter,
+      onShowBoxModelEditor: this.onShowBoxModelEditor,
+      onShowBoxModelHighlighter: this.onShowBoxModelHighlighter,
+    };
+  },
+
+  /**
+   * Returns true if the computed or layout panel is visible, and false otherwise.
+   */
+  isPanelVisible() {
+    return this.inspector.toolbox.currentToolId === "inspector" &&
+           this.inspector.sidebar &&
+           (this.inspector.sidebar.getCurrentTabID() === "layoutview" ||
+            this.inspector.sidebar.getCurrentTabID() === "computedview");
+  },
+
+  /**
+   * Returns true if the layout panel is visible and the current node is valid to
+   * be displayed in the view.
+   */
+  isPanelVisibleAndNodeValid() {
+    return this.isPanelVisible() &&
+           this.inspector.selection.isConnected() &&
+           this.inspector.selection.isElementNode();
+  },
+
+  /**
+   * Starts listening to reflows in the current tab.
+   */
+  trackReflows() {
+    if (!this.reflowFront) {
+      let { target } = this.inspector;
+      if (target.form.reflowActor) {
+        this.reflowFront = ReflowFront(target.client,
+                                       target.form);
+      } else {
+        return;
+      }
+    }
+
+    this.reflowFront.on("reflows", this.updateBoxModel);
+    this.reflowFront.start();
+  },
+
+  /**
+   * Stops listening to reflows in the current tab.
+   */
+  untrackReflows() {
+    if (!this.reflowFront) {
+      return;
+    }
+
+    this.reflowFront.off("reflows", this.updateBoxModel);
+    this.reflowFront.stop();
+  },
+
+  /**
+   * Updates the box model panel by dispatching the new layout data.
+   *
+   * @param  {String} reason
+   *         Optional string describing the reason why the boxmodel is updated.
+   */
+  updateBoxModel(reason) {
+    this._updateReasons = this._updateReasons || [];
+    if (reason) {
+      this._updateReasons.push(reason);
+    }
+
+    let lastRequest = Task.spawn((function* () {
+      if (!(this.isPanelVisible() &&
+          this.inspector.selection.isConnected() &&
+          this.inspector.selection.isElementNode())) {
+        return null;
+      }
+
+      let node = this.inspector.selection.nodeFront;
+      let layout = yield this.inspector.pageStyle.getLayout(node, {
+        autoMargins: true,
+      });
+      let styleEntries = yield this.inspector.pageStyle.getApplied(node, {});
+      this.elementRules = styleEntries.map(e => e.rule);
+
+      // Update the redux store with the latest layout properties and update the box
+      // model view.
+      this.store.dispatch(updateLayout(layout));
+
+      // If a subsequent request has been made, wait for that one instead.
+      if (this._lastRequest != lastRequest) {
+        return this._lastRequest;
+      }
+
+      this.inspector.emit("boxmodel-view-updated", this._updateReasons);
+
+      this._lastRequest = null;
+      this._updateReasons = [];
+
+      return null;
+    }).bind(this)).catch(console.error);
+
+    this._lastRequest = lastRequest;
+  },
+
+  /**
+   * Selection 'new-node-front' event handler.
+   */
+  onNewSelection: function () {
+    if (!this.isPanelVisibleAndNodeValid()) {
+      return;
+    }
+
+    if (this.inspector.selection.isConnected() &&
+        this.inspector.selection.isElementNode()) {
+      this.trackReflows();
+    }
+
+    this.updateBoxModel("new-selection");
+  },
+
+  /**
+   * Hides the box-model highlighter on the currently selected element.
+   */
+  onHideBoxModelHighlighter() {
+    let toolbox = this.inspector.toolbox;
+    toolbox.highlighterUtils.unhighlight();
+  },
+
+  /**
+   * Shows the inplace editor when a box model editable value is clicked on the
+   * box model panel.
+   *
+   * @param  {DOMNode} element
+   *         The element that was clicked.
+   * @param  {Event} event
+   *         The event object.
+   * @param  {String} property
+   *         The name of the property.
+   */
+  onShowBoxModelEditor(element, event, property) {
+    let session = new EditingSession({
+      inspector: this.inspector,
+      doc: this.document,
+      elementRules: this.elementRules,
+    });
+    let initialValue = session.getProperty(property);
+
+    let editor = new InplaceEditor({
+      element: element,
+      initial: initialValue,
+      contentType: InplaceEditor.CONTENT_TYPES.CSS_VALUE,
+      property: {
+        name: property
+      },
+      start: self => {
+        self.elt.parentNode.classList.add("boxmodel-editing");
+      },
+      change: value => {
+        if (NUMERIC.test(value)) {
+          value += "px";
+        }
+
+        let properties = [
+          { name: property, value: value }
+        ];
+
+        if (property.substring(0, 7) == "border-") {
+          let bprop = property.substring(0, property.length - 5) + "style";
+          let style = session.getProperty(bprop);
+          if (!style || style == "none" || style == "hidden") {
+            properties.push({ name: bprop, value: "solid" });
+          }
+        }
+
+        session.setProperties(properties).catch(e => console.error(e));
+      },
+      done: (value, commit) => {
+        editor.elt.parentNode.classList.remove("boxmodel-editing");
+        if (!commit) {
+          session.revert().then(() => {
+            session.destroy();
+          }, e => console.error(e));
+          return;
+        }
+
+        let node = this.inspector.selection.nodeFront;
+        this.inspector.pageStyle.getLayout(node, {
+          autoMargins: true,
+        }).then(layout => {
+          this.store.dispatch(updateLayout(layout));
+        }, e => console.error(e));
+      },
+      contextMenu: this.inspector.onTextBoxContextMenu,
+      cssProperties: getCssProperties(this.inspector.toolbox)
+    }, event);
+  },
+
+  /**
+   * Shows the box-model highlighter on the currently selected element.
+   *
+   * @param  {Object} options
+   *         Options passed to the highlighter actor.
+   */
+  onShowBoxModelHighlighter(options = {}) {
+    let toolbox = this.inspector.toolbox;
+    let nodeFront = this.inspector.selection.nodeFront;
+
+    toolbox.highlighterUtils.highlightNodeFront(nodeFront, options);
+  },
+
+  /**
+   * Handler for the inspector sidebar select event. Starts listening for
+   * "grid-layout-changed" if the layout panel is visible. Otherwise, stop
+   * listening for grid layout changes. Finally, refresh the layout view if
+   * it is visible.
+   */
+  onSidebarSelect() {
+    if (!this.isPanelVisible()) {
+      this.untrackReflows();
+      return;
+    }
+
+    if (this.inspector.selection.isConnected() &&
+        this.inspector.selection.isElementNode()) {
+      this.trackReflows();
+    }
+
+    this.updateBoxModel();
+  },
+
+};
+
+module.exports = BoxModel;
diff --git a/devtools/client/inspector/layout/components/BoxModel.js b/devtools/client/inspector/boxmodel/components/BoxModel.js
similarity index 100%
rename from devtools/client/inspector/layout/components/BoxModel.js
rename to devtools/client/inspector/boxmodel/components/BoxModel.js
diff --git a/devtools/client/inspector/boxmodel/components/BoxModelApp.js b/devtools/client/inspector/boxmodel/components/BoxModelApp.js
new file mode 100644
index 000000000000..2af27ac77c2f
--- /dev/null
+++ b/devtools/client/inspector/boxmodel/components/BoxModelApp.js
@@ -0,0 +1,51 @@
+/* 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 { addons, createClass, createFactory, PropTypes } =
+  require("devtools/client/shared/vendor/react");
+const { connect } = require("devtools/client/shared/vendor/react-redux");
+
+const { LocalizationHelper } = require("devtools/shared/l10n");
+
+const Accordion =
+  createFactory(require("devtools/client/inspector/layout/components/Accordion"));
+const BoxModel = createFactory(require("./BoxModel"));
+
+const Types = require("../types");
+
+const BOXMODEL_STRINGS_URI = "devtools/client/locales/boxmodel.properties";
+const BOXMODEL_L10N = new LocalizationHelper(BOXMODEL_STRINGS_URI);
+
+const BoxModelApp = createClass({
+
+  displayName: "BoxModelApp",
+
+  propTypes: {
+    boxModel: PropTypes.shape(Types.boxModel).isRequired,
+    showBoxModelProperties: PropTypes.bool.isRequired,
+    onHideBoxModelHighlighter: PropTypes.func.isRequired,
+    onShowBoxModelEditor: PropTypes.func.isRequired,
+    onShowBoxModelHighlighter: PropTypes.func.isRequired,
+  },
+
+  mixins: [ addons.PureRenderMixin ],
+
+  render() {
+    return Accordion({
+      items: [
+        {
+          header: BOXMODEL_L10N.getStr("boxmodel.title"),
+          component: BoxModel,
+          componentProps: this.props,
+          opened: true,
+        }
+      ]
+    });
+  },
+
+});
+
+module.exports = connect(state => state)(BoxModelApp);
diff --git a/devtools/client/inspector/layout/components/BoxModelEditable.js b/devtools/client/inspector/boxmodel/components/BoxModelEditable.js
similarity index 100%
rename from devtools/client/inspector/layout/components/BoxModelEditable.js
rename to devtools/client/inspector/boxmodel/components/BoxModelEditable.js
diff --git a/devtools/client/inspector/layout/components/BoxModelInfo.js b/devtools/client/inspector/boxmodel/components/BoxModelInfo.js
similarity index 100%
rename from devtools/client/inspector/layout/components/BoxModelInfo.js
rename to devtools/client/inspector/boxmodel/components/BoxModelInfo.js
diff --git a/devtools/client/inspector/layout/components/BoxModelMain.js b/devtools/client/inspector/boxmodel/components/BoxModelMain.js
similarity index 92%
rename from devtools/client/inspector/layout/components/BoxModelMain.js
rename to devtools/client/inspector/boxmodel/components/BoxModelMain.js
index 42baa7427453..a3980c79d104 100644
--- a/devtools/client/inspector/layout/components/BoxModelMain.js
+++ b/devtools/client/inspector/boxmodel/components/BoxModelMain.js
@@ -37,7 +37,23 @@ module.exports = createClass({
     return layout[property] ? parseFloat(layout[property]) : "-";
   },
 
-  getHeightOrWidthValue(property) {
+  getHeightValue(property) {
+    let { layout } = this.props.boxModel;
+
+    if (property == undefined) {
+      return "-";
+    }
+
+    property -= parseFloat(layout["border-top-width"]) +
+                parseFloat(layout["border-bottom-width"]) +
+                parseFloat(layout["padding-top"]) +
+                parseFloat(layout["padding-bottom"]);
+    property = parseFloat(property.toPrecision(6));
+
+    return property;
+  },
+
+  getWidthValue(property) {
     let { layout } = this.props.boxModel;
 
     if (property == undefined) {
@@ -83,7 +99,7 @@ module.exports = createClass({
   render() {
     let { boxModel, onShowBoxModelEditor } = this.props;
     let { layout } = boxModel;
-    let { width, height } = layout;
+    let { height, width } = layout;
 
     let borderTop = this.getBorderOrPaddingValue("border-top-width");
     let borderRight = this.getBorderOrPaddingValue("border-right-width");
@@ -100,8 +116,8 @@ module.exports = createClass({
     let marginBottom = this.getMarginValue("margin-bottom", "bottom");
     let marginLeft = this.getMarginValue("margin-left", "left");
 
-    width = this.getHeightOrWidthValue(width);
-    height = this.getHeightOrWidthValue(height);
+    height = this.getHeightValue(height);
+    width = this.getWidthValue(width);
 
     return dom.div(
       {
diff --git a/devtools/client/inspector/layout/components/BoxModelProperties.js b/devtools/client/inspector/boxmodel/components/BoxModelProperties.js
similarity index 100%
rename from devtools/client/inspector/layout/components/BoxModelProperties.js
rename to devtools/client/inspector/boxmodel/components/BoxModelProperties.js
diff --git a/devtools/client/inspector/layout/components/ComputedProperty.js b/devtools/client/inspector/boxmodel/components/ComputedProperty.js
similarity index 100%
rename from devtools/client/inspector/layout/components/ComputedProperty.js
rename to devtools/client/inspector/boxmodel/components/ComputedProperty.js
diff --git a/devtools/client/inspector/boxmodel/components/moz.build b/devtools/client/inspector/boxmodel/components/moz.build
new file mode 100644
index 000000000000..02638ae7b291
--- /dev/null
+++ b/devtools/client/inspector/boxmodel/components/moz.build
@@ -0,0 +1,15 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+DevToolsModules(
+    'BoxModel.js',
+    'BoxModelApp.js',
+    'BoxModelEditable.js',
+    'BoxModelInfo.js',
+    'BoxModelMain.js',
+    'BoxModelProperties.js',
+    'ComputedProperty.js',
+)
diff --git a/devtools/client/inspector/boxmodel/moz.build b/devtools/client/inspector/boxmodel/moz.build
new file mode 100644
index 000000000000..6ef44c80c361
--- /dev/null
+++ b/devtools/client/inspector/boxmodel/moz.build
@@ -0,0 +1,19 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+DIRS += [
+    'actions',
+    'components',
+    'reducers',
+    'utils',
+]
+
+DevToolsModules(
+    'box-model.js',
+    'types.js',
+)
+
+BROWSER_CHROME_MANIFESTS += ['test/browser.ini']
diff --git a/devtools/client/inspector/layout/reducers/box-model.js b/devtools/client/inspector/boxmodel/reducers/box-model.js
similarity index 100%
rename from devtools/client/inspector/layout/reducers/box-model.js
rename to devtools/client/inspector/boxmodel/reducers/box-model.js
diff --git a/devtools/client/inspector/boxmodel/reducers/moz.build b/devtools/client/inspector/boxmodel/reducers/moz.build
new file mode 100644
index 000000000000..e2402990ad80
--- /dev/null
+++ b/devtools/client/inspector/boxmodel/reducers/moz.build
@@ -0,0 +1,9 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+DevToolsModules(
+    'box-model.js',
+)
diff --git a/devtools/client/inspector/components/test/.eslintrc.js b/devtools/client/inspector/boxmodel/test/.eslintrc.js
similarity index 100%
rename from devtools/client/inspector/components/test/.eslintrc.js
rename to devtools/client/inspector/boxmodel/test/.eslintrc.js
diff --git a/devtools/client/inspector/components/test/browser.ini b/devtools/client/inspector/boxmodel/test/browser.ini
similarity index 94%
rename from devtools/client/inspector/components/test/browser.ini
rename to devtools/client/inspector/boxmodel/test/browser.ini
index be937ecfd3d7..c9881c903937 100644
--- a/devtools/client/inspector/components/test/browser.ini
+++ b/devtools/client/inspector/boxmodel/test/browser.ini
@@ -21,9 +21,11 @@ support-files =
 [browser_boxmodel_editablemodel_stylerules.js]
 [browser_boxmodel_guides.js]
 [browser_boxmodel_navigation.js]
+skip-if = true # Bug 1336198
 [browser_boxmodel_rotate-labels-on-sides.js]
 [browser_boxmodel_sync.js]
 [browser_boxmodel_tooltips.js]
+skip-if = true # Bug 1336198
 [browser_boxmodel_update-after-navigation.js]
 [browser_boxmodel_update-after-reload.js]
 # [browser_boxmodel_update-in-iframes.js]
diff --git a/devtools/client/inspector/components/test/browser_boxmodel.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel.js
similarity index 58%
rename from devtools/client/inspector/components/test/browser_boxmodel.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel.js
index d26d9061ce52..9e085cafe232 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel.js
@@ -10,118 +10,118 @@
 // Expected values:
 var res1 = [
   {
-    selector: "#old-boxmodel-element-size",
+    selector: ".boxmodel-element-size",
     value: "160" + "\u00D7" + "160.117"
   },
   {
-    selector: ".old-boxmodel-size > span",
+    selector: ".boxmodel-size > span",
     value: "100" + "\u00D7" + "100.117"
   },
   {
-    selector: ".old-boxmodel-margin.old-boxmodel-top > span",
+    selector: ".boxmodel-margin.boxmodel-top > span",
     value: 30
   },
   {
-    selector: ".old-boxmodel-margin.old-boxmodel-left > span",
+    selector: ".boxmodel-margin.boxmodel-left > span",
     value: "auto"
   },
   {
-    selector: ".old-boxmodel-margin.old-boxmodel-bottom > span",
+    selector: ".boxmodel-margin.boxmodel-bottom > span",
     value: 30
   },
   {
-    selector: ".old-boxmodel-margin.old-boxmodel-right > span",
+    selector: ".boxmodel-margin.boxmodel-right > span",
     value: "auto"
   },
   {
-    selector: ".old-boxmodel-padding.old-boxmodel-top > span",
+    selector: ".boxmodel-padding.boxmodel-top > span",
     value: 20
   },
   {
-    selector: ".old-boxmodel-padding.old-boxmodel-left > span",
+    selector: ".boxmodel-padding.boxmodel-left > span",
     value: 20
   },
   {
-    selector: ".old-boxmodel-padding.old-boxmodel-bottom > span",
+    selector: ".boxmodel-padding.boxmodel-bottom > span",
     value: 20
   },
   {
-    selector: ".old-boxmodel-padding.old-boxmodel-right > span",
+    selector: ".boxmodel-padding.boxmodel-right > span",
     value: 20
   },
   {
-    selector: ".old-boxmodel-border.old-boxmodel-top > span",
+    selector: ".boxmodel-border.boxmodel-top > span",
     value: 10
   },
   {
-    selector: ".old-boxmodel-border.old-boxmodel-left > span",
+    selector: ".boxmodel-border.boxmodel-left > span",
     value: 10
   },
   {
-    selector: ".old-boxmodel-border.old-boxmodel-bottom > span",
+    selector: ".boxmodel-border.boxmodel-bottom > span",
     value: 10
   },
   {
-    selector: ".old-boxmodel-border.old-boxmodel-right > span",
+    selector: ".boxmodel-border.boxmodel-right > span",
     value: 10
   },
 ];
 
 var res2 = [
   {
-    selector: "#old-boxmodel-element-size",
+    selector: ".boxmodel-element-size",
     value: "190" + "\u00D7" + "210"
   },
   {
-    selector: ".old-boxmodel-size > span",
+    selector: ".boxmodel-size > span",
     value: "100" + "\u00D7" + "150"
   },
   {
-    selector: ".old-boxmodel-margin.old-boxmodel-top > span",
+    selector: ".boxmodel-margin.boxmodel-top > span",
     value: 30
   },
   {
-    selector: ".old-boxmodel-margin.old-boxmodel-left > span",
+    selector: ".boxmodel-margin.boxmodel-left > span",
     value: "auto"
   },
   {
-    selector: ".old-boxmodel-margin.old-boxmodel-bottom > span",
+    selector: ".boxmodel-margin.boxmodel-bottom > span",
     value: 30
   },
   {
-    selector: ".old-boxmodel-margin.old-boxmodel-right > span",
+    selector: ".boxmodel-margin.boxmodel-right > span",
     value: "auto"
   },
   {
-    selector: ".old-boxmodel-padding.old-boxmodel-top > span",
+    selector: ".boxmodel-padding.boxmodel-top > span",
     value: 20
   },
   {
-    selector: ".old-boxmodel-padding.old-boxmodel-left > span",
+    selector: ".boxmodel-padding.boxmodel-left > span",
     value: 20
   },
   {
-    selector: ".old-boxmodel-padding.old-boxmodel-bottom > span",
+    selector: ".boxmodel-padding.boxmodel-bottom > span",
     value: 20
   },
   {
-    selector: ".old-boxmodel-padding.old-boxmodel-right > span",
+    selector: ".boxmodel-padding.boxmodel-right > span",
     value: 50
   },
   {
-    selector: ".old-boxmodel-border.old-boxmodel-top > span",
+    selector: ".boxmodel-border.boxmodel-top > span",
     value: 10
   },
   {
-    selector: ".old-boxmodel-border.old-boxmodel-left > span",
+    selector: ".boxmodel-border.boxmodel-left > span",
     value: 10
   },
   {
-    selector: ".old-boxmodel-border.old-boxmodel-bottom > span",
+    selector: ".boxmodel-border.boxmodel-bottom > span",
     value: 10
   },
   {
-    selector: ".old-boxmodel-border.old-boxmodel-right > span",
+    selector: ".boxmodel-border.boxmodel-right > span",
     value: 10
   },
 ];
@@ -142,7 +142,7 @@ add_task(function* () {
 
 function* testInitialValues(inspector, view) {
   info("Test that the initial values of the box model are correct");
-  let viewdoc = view.doc;
+  let viewdoc = view.document;
 
   for (let i = 0; i < res1.length; i++) {
     let elt = viewdoc.querySelector(res1[i].selector);
@@ -153,7 +153,7 @@ function* testInitialValues(inspector, view) {
 
 function* testChangingValues(inspector, view, testActor) {
   info("Test that changing the document updates the box model");
-  let viewdoc = view.doc;
+  let viewdoc = view.document;
 
   let onUpdated = waitForUpdate(inspector);
   yield testActor.setAttribute("div", "style",
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_editablemodel.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel.js
similarity index 74%
rename from devtools/client/inspector/components/test/browser_boxmodel_editablemodel.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel.js
index 5bb882dd6e7b..37736152011b 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_editablemodel.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel.js
@@ -36,21 +36,21 @@ function* testEditingMargins(inspector, view, testActor) {
      "Should be no margin-top on the element.");
   yield selectNode("#div1", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-margin.old-boxmodel-top > span");
+  let span = view.document.querySelector(".boxmodel-margin.boxmodel-top > span");
   is(span.textContent, 5, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "5px", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("3", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("3", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is((yield getStyle(testActor, "#div1", "margin-top")), "3px",
      "Should have updated the margin.");
 
-  EventUtils.synthesizeKey("VK_ESCAPE", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_ESCAPE", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is((yield getStyle(testActor, "#div1", "margin-top")), "",
@@ -66,35 +66,35 @@ function* testKeyBindings(inspector, view, testActor) {
      "Should be no margin-top on the element.");
   yield selectNode("#div1", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-margin.old-boxmodel-left > span");
+  let span = view.document.querySelector(".boxmodel-margin.boxmodel-left > span");
   is(span.textContent, 10, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "10px", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("VK_UP", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_UP", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "11px", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div1", "margin-left")), "11px",
      "Should have updated the margin.");
 
-  EventUtils.synthesizeKey("VK_DOWN", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_DOWN", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "10px", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div1", "margin-left")), "10px",
      "Should have updated the margin.");
 
-  EventUtils.synthesizeKey("VK_UP", { shiftKey: true }, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_UP", { shiftKey: true }, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "20px", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div1", "margin-left")), "20px",
      "Should have updated the margin.");
-  EventUtils.synthesizeKey("VK_RETURN", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_RETURN", {}, view.document.defaultView);
 
   is((yield getStyle(testActor, "#div1", "margin-left")), "20px",
      "Should be the right margin-top on the element.");
@@ -109,22 +109,22 @@ function* testEscapeToUndo(inspector, view, testActor) {
      "Should be the right margin-top on the element.");
   yield selectNode("#div1", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-margin.old-boxmodel-left > span");
+  let span = view.document.querySelector(".boxmodel-margin.boxmodel-left > span");
   is(span.textContent, 20, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "20px", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("VK_DELETE", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_DELETE", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div1", "margin-left")), "",
      "Should have updated the margin.");
 
-  EventUtils.synthesizeKey("VK_ESCAPE", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_ESCAPE", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is((yield getStyle(testActor, "#div1", "margin-left")), "20px",
@@ -140,22 +140,22 @@ function* testDeletingValue(inspector, view, testActor) {
 
   yield selectNode("#div1", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-margin.old-boxmodel-right > span");
+  let span = view.document.querySelector(".boxmodel-margin.boxmodel-right > span");
   is(span.textContent, 15, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "15px", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("VK_DELETE", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_DELETE", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div1", "margin-right")), "",
      "Should have updated the margin.");
 
-  EventUtils.synthesizeKey("VK_RETURN", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_RETURN", {}, view.document.defaultView);
 
   is((yield getStyle(testActor, "#div1", "margin-right")), "",
      "Should be the right margin-top on the element.");
@@ -167,26 +167,26 @@ function* testRefocusingOnClick(inspector, view, testActor) {
 
   yield selectNode("#div4", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-margin.old-boxmodel-top > span");
+  let span = view.document.querySelector(".boxmodel-margin.boxmodel-top > span");
   is(span.textContent, 1, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
 
   info("Click in the already opened editor input");
-  EventUtils.synthesizeMouseAtCenter(editor, {}, view.doc.defaultView);
-  is(editor, view.doc.activeElement,
+  EventUtils.synthesizeMouseAtCenter(editor, {}, view.document.defaultView);
+  is(editor, view.document.activeElement,
     "Inplace editor input should still have focus.");
 
   info("Check the input can still be used as expected");
-  EventUtils.synthesizeKey("VK_UP", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_UP", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "2px", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div4", "margin-top")), "2px",
      "Should have updated the margin.");
-  EventUtils.synthesizeKey("VK_RETURN", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_RETURN", {}, view.document.defaultView);
 
   is((yield getStyle(testActor, "#div4", "margin-top")), "2px",
      "Should be the right margin-top on the element.");
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_editablemodel_allproperties.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_allproperties.js
similarity index 74%
rename from devtools/client/inspector/components/test/browser_boxmodel_editablemodel_allproperties.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_allproperties.js
index ca5194266319..ab49a191429c 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_editablemodel_allproperties.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_allproperties.js
@@ -32,22 +32,22 @@ function* testEditing(inspector, view, testActor) {
 
   yield selectNode("#div1", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-padding.old-boxmodel-bottom > span");
+  let span = view.document.querySelector(".boxmodel-padding.boxmodel-bottom > span");
   is(span.textContent, 5, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "5px", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("7", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("7", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "7", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div1", "padding-bottom")), "7px",
      "Should have updated the padding");
 
-  EventUtils.synthesizeKey("VK_RETURN", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_RETURN", {}, view.document.defaultView);
 
   is((yield getStyle(testActor, "#div1", "padding-bottom")), "7px",
      "Should be the right padding.");
@@ -63,22 +63,22 @@ function* testEditingAndCanceling(inspector, view, testActor) {
 
   yield selectNode("#div1", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-padding.old-boxmodel-left > span");
+  let span = view.document.querySelector(".boxmodel-padding.boxmodel-left > span");
   is(span.textContent, 5, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "5px", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("8", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("8", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "8", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div1", "padding-left")), "8px",
      "Should have updated the padding");
 
-  EventUtils.synthesizeKey("VK_ESCAPE", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_ESCAPE", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is((yield getStyle(testActor, "#div1", "padding-left")), "5px",
@@ -91,22 +91,22 @@ function* testDeleting(inspector, view, testActor) {
 
   yield selectNode("#div1", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-padding.old-boxmodel-left > span");
+  let span = view.document.querySelector(".boxmodel-padding.boxmodel-left > span");
   is(span.textContent, 5, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "5px", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("VK_DELETE", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_DELETE", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div1", "padding-left")), "",
      "Should have updated the padding");
 
-  EventUtils.synthesizeKey("VK_RETURN", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_RETURN", {}, view.document.defaultView);
 
   is((yield getStyle(testActor, "#div1", "padding-left")), "",
      "Should be the right padding.");
@@ -122,22 +122,22 @@ function* testDeletingAndCanceling(inspector, view, testActor) {
 
   yield selectNode("#div1", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-padding.old-boxmodel-left > span");
+  let span = view.document.querySelector(".boxmodel-padding.boxmodel-left > span");
   is(span.textContent, 5, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "5px", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("VK_DELETE", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_DELETE", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div1", "padding-left")), "",
      "Should have updated the padding");
 
-  EventUtils.synthesizeKey("VK_ESCAPE", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_ESCAPE", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is((yield getStyle(testActor, "#div1", "padding-left")), "5px",
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_editablemodel_bluronclick.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_bluronclick.js
similarity index 69%
rename from devtools/client/inspector/components/test/browser_boxmodel_editablemodel_bluronclick.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_bluronclick.js
index f56f584ddf95..c251dfbc162f 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_editablemodel_bluronclick.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_bluronclick.js
@@ -30,45 +30,45 @@ add_task(function* () {
 
 function* testClickingOutsideEditor(view) {
   info("Test that clicking outside the editor blurs it");
-  let span = view.doc.querySelector(".old-boxmodel-margin.old-boxmodel-top > span");
+  let span = view.document.querySelector(".boxmodel-margin.boxmodel-top > span");
   is(span.textContent, 10, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
 
   info("Click next to the opened editor input.");
   let onBlur = once(editor, "blur");
   let rect = editor.getBoundingClientRect();
   EventUtils.synthesizeMouse(editor, rect.width + 10, rect.height / 2, {},
-    view.doc.defaultView);
+    view.document.defaultView);
   yield onBlur;
 
-  is(view.doc.querySelector(".styleinspector-propertyeditor"), null,
+  is(view.document.querySelector(".styleinspector-propertyeditor"), null,
     "Inplace editor has been removed.");
 }
 
 function* testClickingBelowContainer(view) {
   info("Test that clicking below the box-model container blurs it");
-  let span = view.doc.querySelector(".old-boxmodel-margin.old-boxmodel-top > span");
+  let span = view.document.querySelector(".boxmodel-margin.boxmodel-top > span");
   is(span.textContent, 10, "Should have the right value in the box model.");
 
-  info("Test that clicking below the old-boxmodel-container blurs the opened editor");
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  info("Test that clicking below the boxmodel-container blurs the opened editor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
 
   let onBlur = once(editor, "blur");
-  let container = view.doc.querySelector("#old-boxmodel-container");
+  let container = view.document.querySelector(".boxmodel-container");
   // Using getBoxQuads here because getBoundingClientRect (and therefore synthesizeMouse)
   // use an erroneous height of ~50px for the boxmodel-container.
   let bounds = container.getBoxQuads({relativeTo: view.doc})[0].bounds;
   EventUtils.synthesizeMouseAtPoint(
     bounds.left + 10,
     bounds.top + bounds.height + 10,
-    {}, view.doc.defaultView);
+    {}, view.document.defaultView);
   yield onBlur;
 
-  is(view.doc.querySelector(".styleinspector-propertyeditor"), null,
+  is(view.document.querySelector(".styleinspector-propertyeditor"), null,
     "Inplace editor has been removed.");
 }
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_editablemodel_border.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_border.js
similarity index 82%
rename from devtools/client/inspector/components/test/browser_boxmodel_editablemodel_border.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_border.js
index 5550a66423a4..197ef99d3b47 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_editablemodel_border.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_border.js
@@ -24,15 +24,15 @@ add_task(function* () {
      "Should have the right border");
   yield selectNode("#div1", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-border.old-boxmodel-top > span");
+  let span = view.document.querySelector(".boxmodel-border.boxmodel-top > span");
   is(span.textContent, 0, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "0", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("1", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("1", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "1", "Should have the right value in the editor.");
@@ -41,7 +41,7 @@ add_task(function* () {
   is((yield getStyle(testActor, "#div1", "border-top-style")), "solid",
      "Should have the right border");
 
-  EventUtils.synthesizeKey("VK_ESCAPE", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_ESCAPE", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is((yield getStyle(testActor, "#div1", "border-top-width")), "",
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_editablemodel_stylerules.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_stylerules.js
similarity index 74%
rename from devtools/client/inspector/components/test/browser_boxmodel_editablemodel_stylerules.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_stylerules.js
index f3f41e4d04ed..28ba89898062 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_editablemodel_stylerules.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_editablemodel_stylerules.js
@@ -31,30 +31,30 @@ function* testUnits(inspector, view, testActor) {
      "Should have the right padding");
   yield selectNode("#div1", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-padding.old-boxmodel-top > span");
+  let span = view.document.querySelector(".boxmodel-padding.boxmodel-top > span");
   is(span.textContent, 3, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "3px", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("1", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("1", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
-  EventUtils.synthesizeKey("e", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("e", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is((yield getStyle(testActor, "#div1", "padding-top")), "",
      "An invalid value is handled cleanly");
 
-  EventUtils.synthesizeKey("m", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("m", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "1em", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div1", "padding-top")),
      "1em", "Should have updated the padding.");
 
-  EventUtils.synthesizeKey("VK_RETURN", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_RETURN", {}, view.document.defaultView);
 
   is((yield getStyle(testActor, "#div1", "padding-top")), "1em",
      "Should be the right padding.");
@@ -68,22 +68,22 @@ function* testValueComesFromStyleRule(inspector, view, testActor) {
      "Should have the right border-bottom-width");
   yield selectNode("#div2", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-border.old-boxmodel-bottom > span");
+  let span = view.document.querySelector(".boxmodel-border.boxmodel-bottom > span");
   is(span.textContent, 16, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "1em", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("0", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("0", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
 
   is(editor.value, "0", "Should have the right value in the editor.");
   is((yield getStyle(testActor, "#div2", "border-bottom-width")), "0px",
      "Should have updated the border.");
 
-  EventUtils.synthesizeKey("VK_RETURN", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_RETURN", {}, view.document.defaultView);
 
   is((yield getStyle(testActor, "#div2", "border-bottom-width")), "0px",
      "Should be the right border-bottom-width.");
@@ -97,15 +97,15 @@ function* testShorthandsAreParsed(inspector, view, testActor) {
      "Should have the right padding");
   yield selectNode("#div3", inspector);
 
-  let span = view.doc.querySelector(".old-boxmodel-padding.old-boxmodel-right > span");
+  let span = view.document.querySelector(".boxmodel-padding.boxmodel-right > span");
   is(span.textContent, 32, "Should have the right value in the box model.");
 
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "2em", "Should have the right value in the editor.");
 
-  EventUtils.synthesizeKey("VK_RETURN", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_RETURN", {}, view.document.defaultView);
 
   is((yield getStyle(testActor, "#div3", "padding-right")), "",
      "Should be the right padding.");
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_guides.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_guides.js
similarity index 89%
rename from devtools/client/inspector/components/test/browser_boxmodel_guides.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_guides.js
index 9dcaaa609cce..51457e25cd46 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_guides.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_guides.js
@@ -28,16 +28,16 @@ add_task(function* () {
     highlighterOptions = options;
   };
 
-  let elt = view.doc.getElementById("old-boxmodel-margins");
+  let elt = view.document.querySelector(".boxmodel-margins");
   yield testGuideOnLayoutHover(elt, "margin", inspector, view);
 
-  elt = view.doc.getElementById("old-boxmodel-borders");
+  elt = view.document.querySelector(".boxmodel-borders");
   yield testGuideOnLayoutHover(elt, "border", inspector, view);
 
-  elt = view.doc.getElementById("old-boxmodel-padding");
+  elt = view.document.querySelector(".boxmodel-paddings");
   yield testGuideOnLayoutHover(elt, "padding", inspector, view);
 
-  elt = view.doc.getElementById("old-boxmodel-content");
+  elt = view.document.querySelector(".boxmodel-content");
   yield testGuideOnLayoutHover(elt, "content", inspector, view);
 });
 
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_navigation.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_navigation.js
similarity index 75%
rename from devtools/client/inspector/components/test/browser_boxmodel_navigation.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_navigation.js
index 6b8439710227..deee191fd2aa 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_navigation.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_navigation.js
@@ -29,50 +29,50 @@ add_task(function* () {
 function* testInitialFocus(inspector, view) {
   info("Test that the focus is on margin layout.");
   let viewdoc = view.doc;
-  let boxmodel = viewdoc.getElementById("old-boxmodel-wrapper");
+  let boxmodel = viewdoc.getElementById("boxmodel-wrapper");
   boxmodel.focus();
   EventUtils.synthesizeKey("VK_RETURN", {});
 
-  is(boxmodel.getAttribute("aria-activedescendant"), "old-boxmodel-margins",
+  is(boxmodel.getAttribute("aria-activedescendant"), "boxmodel-margins",
     "Should be set to the margin layout.");
 }
 
 function* testChangingLevels(inspector, view) {
   info("Test that using arrow keys updates level.");
   let viewdoc = view.doc;
-  let boxmodel = viewdoc.getElementById("old-boxmodel-wrapper");
+  let boxmodel = viewdoc.getElementById("boxmodel-wrapper");
   boxmodel.focus();
   EventUtils.synthesizeKey("VK_RETURN", {});
   EventUtils.synthesizeKey("VK_ESCAPE", {});
 
   EventUtils.synthesizeKey("VK_DOWN", {});
-  is(boxmodel.getAttribute("aria-activedescendant"), "old-boxmodel-borders",
+  is(boxmodel.getAttribute("aria-activedescendant"), "boxmodel-borders",
     "Should be set to the border layout.");
 
   EventUtils.synthesizeKey("VK_DOWN", {});
-  is(boxmodel.getAttribute("aria-activedescendant"), "old-boxmodel-padding",
+  is(boxmodel.getAttribute("aria-activedescendant"), "boxmodel-padding",
     "Should be set to the padding layout.");
 
   EventUtils.synthesizeKey("VK_UP", {});
-  is(boxmodel.getAttribute("aria-activedescendant"), "old-boxmodel-borders",
+  is(boxmodel.getAttribute("aria-activedescendant"), "boxmodel-borders",
     "Should be set to the border layout.");
 
   EventUtils.synthesizeKey("VK_UP", {});
-  is(boxmodel.getAttribute("aria-activedescendant"), "old-boxmodel-margins",
+  is(boxmodel.getAttribute("aria-activedescendant"), "boxmodel-margins",
     "Should be set to the margin layout.");
 }
 
 function* testTabbingWrapAround(inspector, view) {
   info("Test that using arrow keys updates level.");
   let viewdoc = view.doc;
-  let boxmodel = viewdoc.getElementById("old-boxmodel-wrapper");
+  let boxmodel = viewdoc.getElementById("boxmodel-wrapper");
   boxmodel.focus();
   EventUtils.synthesizeKey("VK_RETURN", {});
 
   let editLevel = boxmodel.getAttribute("aria-activedescendant");
   let dataLevel = viewdoc.getElementById(editLevel).getAttribute("data-box");
   let editBoxes = [...viewdoc.querySelectorAll(
-    `[data-box="${dataLevel}"].old-boxmodel-editable`)];
+    `[data-box="${dataLevel}"].boxmodel-editable`)];
 
   EventUtils.synthesizeKey("VK_ESCAPE", {});
   editBoxes[3].focus();
@@ -87,12 +87,12 @@ function* testTabbingWrapAround(inspector, view) {
 function* testChangingLevelsByClicking(inspector, view) {
   info("Test that clicking on levels updates level.");
   let viewdoc = view.doc;
-  let boxmodel = viewdoc.getElementById("old-boxmodel-wrapper");
+  let boxmodel = viewdoc.getElementById("boxmodel-wrapper");
   boxmodel.focus();
 
-  let marginLayout = viewdoc.getElementById("old-boxmodel-margins");
-  let borderLayout = viewdoc.getElementById("old-boxmodel-borders");
-  let paddingLayout = viewdoc.getElementById("old-boxmodel-padding");
+  let marginLayout = viewdoc.getElementById("boxmodel-margins");
+  let borderLayout = viewdoc.getElementById("boxmodel-borders");
+  let paddingLayout = viewdoc.getElementById("boxmodel-padding");
   let layouts = [paddingLayout, borderLayout, marginLayout];
 
   layouts.forEach(layout => {
diff --git a/devtools/client/inspector/boxmodel/test/browser_boxmodel_rotate-labels-on-sides.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_rotate-labels-on-sides.js
new file mode 100644
index 000000000000..e931830b534f
--- /dev/null
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_rotate-labels-on-sides.js
@@ -0,0 +1,49 @@
+/* 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";
+
+// Test that longer values are rotated on the side
+
+const res1 = [
+  {selector: ".boxmodel-margin.boxmodel-top > span", value: 30},
+  {selector: ".boxmodel-margin.boxmodel-left > span", value: "auto"},
+  {selector: ".boxmodel-margin.boxmodel-bottom > span", value: 30},
+  {selector: ".boxmodel-margin.boxmodel-right > span", value: "auto"},
+  {selector: ".boxmodel-padding.boxmodel-top > span", value: 20},
+  {selector: ".boxmodel-padding.boxmodel-left > span", value: 2000000},
+  {selector: ".boxmodel-padding.boxmodel-bottom > span", value: 20},
+  {selector: ".boxmodel-padding.boxmodel-right > span", value: 20},
+  {selector: ".boxmodel-border.boxmodel-top > span", value: 10},
+  {selector: ".boxmodel-border.boxmodel-left > span", value: 10},
+  {selector: ".boxmodel-border.boxmodel-bottom > span", value: 10},
+  {selector: ".boxmodel-border.boxmodel-right > span", value: 10},
+];
+
+const TEST_URI = encodeURIComponent([
+  "<style>",
+  "div { border:10px solid black; padding: 20px 20px 20px 2000000px; " +
+  "margin: 30px auto; }",
+  "</style>",
+  "<div></div>"
+].join(""));
+const LONG_TEXT_ROTATE_LIMIT = 3;
+
+add_task(function* () {
+  yield addTab("data:text/html," + TEST_URI);
+  let {inspector, view} = yield openBoxModelView();
+  yield selectNode("div", inspector);
+
+  for (let i = 0; i < res1.length; i++) {
+    let elt = view.document.querySelector(res1[i].selector);
+    let isLong = elt.textContent.length > LONG_TEXT_ROTATE_LIMIT;
+    let classList = elt.parentNode.classList;
+    let canBeRotated = classList.contains("boxmodel-left") ||
+                       classList.contains("boxmodel-right");
+    let isRotated = classList.contains("boxmodel-rotate");
+
+    is(canBeRotated && isLong,
+      isRotated, res1[i].selector + " correctly rotated.");
+  }
+});
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_sync.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_sync.js
similarity index 77%
rename from devtools/client/inspector/components/test/browser_boxmodel_sync.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_sync.js
index c0fde5c80b86..382675ad2d2d 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_sync.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_sync.js
@@ -17,14 +17,14 @@ add_task(function* () {
   yield selectNode("p", inspector);
 
   info("Modify padding-bottom in box model view");
-  let span = view.doc.querySelector(".old-boxmodel-padding.old-boxmodel-bottom > span");
-  EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
-  let editor = view.doc.querySelector(".styleinspector-propertyeditor");
+  let span = view.document.querySelector(".boxmodel-padding.boxmodel-bottom > span");
+  EventUtils.synthesizeMouseAtCenter(span, {}, view.document.defaultView);
+  let editor = view.document.querySelector(".styleinspector-propertyeditor");
 
-  EventUtils.synthesizeKey("7", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("7", {}, view.document.defaultView);
   yield waitForUpdate(inspector);
   is(editor.value, "7", "Should have the right value in the editor.");
-  EventUtils.synthesizeKey("VK_RETURN", {}, view.doc.defaultView);
+  EventUtils.synthesizeKey("VK_RETURN", {}, view.document.defaultView);
 
   let onRuleViewRefreshed = once(inspector, "rule-view-refreshed");
   let onRuleViewSelected = once(inspector.sidebar, "ruleview-selected");
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_tooltips.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_tooltips.js
similarity index 83%
rename from devtools/client/inspector/components/test/browser_boxmodel_tooltips.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_tooltips.js
index cdbbd6885bb4..6f5997635fe8 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_tooltips.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_tooltips.js
@@ -76,24 +76,24 @@ add_task(function* () {
 
   info("Checking the regions tooltips");
 
-  ok(view.doc.querySelector("#old-boxmodel-margins").hasAttribute("title"),
+  ok(view.document.querySelector(".boxmodel-margins").hasAttribute("title"),
     "The margin region has a tooltip");
-  is(view.doc.querySelector("#old-boxmodel-margins").getAttribute("title"), "margin",
+  is(view.document.querySelector(".boxmodel-margins").getAttribute("title"), "margin",
     "The margin region has the correct tooltip content");
 
-  ok(view.doc.querySelector("#old-boxmodel-borders").hasAttribute("title"),
+  ok(view.document.querySelector(".boxmodel-borders").hasAttribute("title"),
     "The border region has a tooltip");
-  is(view.doc.querySelector("#old-boxmodel-borders").getAttribute("title"), "border",
+  is(view.document.querySelector(".boxmodel-borders").getAttribute("title"), "border",
     "The border region has the correct tooltip content");
 
-  ok(view.doc.querySelector("#old-boxmodel-padding").hasAttribute("title"),
+  ok(view.document.querySelector(".boxmodel-paddings").hasAttribute("title"),
     "The padding region has a tooltip");
-  is(view.doc.querySelector("#old-boxmodel-padding").getAttribute("title"), "padding",
+  is(view.document.querySelector(".boxmodel-paddings").getAttribute("title"), "padding",
     "The padding region has the correct tooltip content");
 
-  ok(view.doc.querySelector("#old-boxmodel-content").hasAttribute("title"),
+  ok(view.document.querySelector(".boxmodel-content").hasAttribute("title"),
     "The content region has a tooltip");
-  is(view.doc.querySelector("#old-boxmodel-content").getAttribute("title"), "content",
+  is(view.document.querySelector(".boxmodel-content").getAttribute("title"), "content",
     "The content region has the correct tooltip content");
 
   for (let {selector, values} of VALUES_TEST_DATA) {
@@ -108,7 +108,7 @@ add_task(function* () {
 
       let name = view.map[key].property;
       let expectedTooltipData = values.find(o => o.name === name);
-      let el = view.doc.querySelector(view.map[key].selector);
+      let el = view.document.querySelector(view.map[key].selector);
 
       ok(el.hasAttribute("title"), "The " + name + " value has a tooltip");
 
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_update-after-navigation.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_update-after-navigation.js
similarity index 86%
rename from devtools/client/inspector/components/test/browser_boxmodel_update-after-navigation.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_update-after-navigation.js
index 62918310ceea..dfcf8ceefe5a 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_update-after-navigation.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_update-after-navigation.js
@@ -17,14 +17,16 @@ add_task(function* () {
   yield testFirstPage(inspector, view, testActor);
 
   info("Navigate to the second page");
+  let onMarkupLoaded = waitForMarkupLoaded(inspector);
   yield testActor.eval(`content.location.href="${IFRAME2}"`);
-  yield inspector.once("markuploaded");
+  yield onMarkupLoaded;
 
   yield testSecondPage(inspector, view, testActor);
 
   info("Go back to the first page");
+  onMarkupLoaded = waitForMarkupLoaded(inspector);
   yield testActor.eval("content.history.back();");
-  yield inspector.once("markuploaded");
+  yield onMarkupLoaded;
 
   yield testBackToFirstPage(inspector, view, testActor);
 });
@@ -32,12 +34,11 @@ add_task(function* () {
 function* testFirstPage(inspector, view, testActor) {
   info("Test that the box model view works on the first page");
 
-  info("Selecting the test node");
   yield selectNode("p", inspector);
 
   info("Checking that the box model view shows the right value");
-  let paddingElt = view.doc.querySelector(
-    ".old-boxmodel-padding.old-boxmodel-top > span");
+  let paddingElt = view.document.querySelector(
+    ".boxmodel-padding.boxmodel-top > span");
   is(paddingElt.textContent, "50");
 
   info("Listening for box model view changes and modifying the padding");
@@ -53,11 +54,10 @@ function* testFirstPage(inspector, view, testActor) {
 function* testSecondPage(inspector, view, testActor) {
   info("Test that the box model view works on the second page");
 
-  info("Selecting the test node");
   yield selectNode("p", inspector);
 
   info("Checking that the box model view shows the right value");
-  let sizeElt = view.doc.querySelector(".old-boxmodel-size > span");
+  let sizeElt = view.document.querySelector(".boxmodel-size > span");
   is(sizeElt.textContent, "100" + "\u00D7" + "100");
 
   info("Listening for box model view changes and modifying the size");
@@ -73,13 +73,12 @@ function* testSecondPage(inspector, view, testActor) {
 function* testBackToFirstPage(inspector, view, testActor) {
   info("Test that the box model view works on the first page after going back");
 
-  info("Selecting the test node");
   yield selectNode("p", inspector);
 
   info("Checking that the box model view shows the right value, which is the" +
     "modified value from step one because of the bfcache");
-  let paddingElt = view.doc.querySelector(
-    ".old-boxmodel-padding.old-boxmodel-top > span");
+  let paddingElt = view.document.querySelector(
+    ".boxmodel-padding.boxmodel-top > span");
   is(paddingElt.textContent, "20");
 
   info("Listening for box model view changes and modifying the padding");
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_update-after-reload.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_update-after-reload.js
similarity index 87%
rename from devtools/client/inspector/components/test/browser_boxmodel_update-after-reload.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_update-after-reload.js
index 111031e115d2..f1ed222949a4 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_update-after-reload.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_update-after-reload.js
@@ -14,20 +14,20 @@ add_task(function* () {
   yield assertBoxModelView(inspector, view, testActor);
 
   info("Reload the page");
+  let onMarkupLoaded = waitForMarkupLoaded(inspector);
   yield testActor.reload();
-  yield inspector.once("markuploaded");
+  yield onMarkupLoaded;
 
   info("Test that the box model view works on the reloaded page");
   yield assertBoxModelView(inspector, view, testActor);
 });
 
 function* assertBoxModelView(inspector, view, testActor) {
-  info("Selecting the test node");
   yield selectNode("p", inspector);
 
   info("Checking that the box model view shows the right value");
-  let paddingElt = view.doc.querySelector(
-    ".old-boxmodel-padding.old-boxmodel-top > span");
+  let paddingElt = view.document.querySelector(
+    ".boxmodel-padding.boxmodel-top > span");
   is(paddingElt.textContent, "50");
 
   info("Listening for box model view changes and modifying the padding");
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_update-in-iframes.js b/devtools/client/inspector/boxmodel/test/browser_boxmodel_update-in-iframes.js
similarity index 93%
rename from devtools/client/inspector/components/test/browser_boxmodel_update-in-iframes.js
rename to devtools/client/inspector/boxmodel/test/browser_boxmodel_update-in-iframes.js
index 9aedb1b581ac..6aa10e441ae9 100644
--- a/devtools/client/inspector/components/test/browser_boxmodel_update-in-iframes.js
+++ b/devtools/client/inspector/boxmodel/test/browser_boxmodel_update-in-iframes.js
@@ -22,7 +22,7 @@ function* testResizingInIframe(inspector, view, testActor) {
   yield selectNodeInIframe2("div", inspector);
 
   info("Checking that the box model view shows the right value");
-  let sizeElt = view.doc.querySelector(".old-boxmodel-size > span");
+  let sizeElt = view.document.querySelector(".boxmodel-size > span");
   is(sizeElt.textContent, "400\u00D7200");
 
   info("Listening for box model view changes and modifying its size");
@@ -40,14 +40,15 @@ function* testReflowsAfterIframeDeletion(inspector, view, testActor) {
        "iframe");
 
   info("Deleting the iframe2");
+  let onInspectorUpdated = inspector.once("inspector-updated");
   yield removeIframe2(testActor);
-  yield inspector.once("inspector-updated");
+  yield onInspectorUpdated;
 
   info("Selecting the test node in iframe1");
   yield selectNodeInIframe1("p", inspector);
 
   info("Checking that the box model view shows the right value");
-  let sizeElt = view.doc.querySelector(".old-boxmodel-size > span");
+  let sizeElt = view.document.querySelector(".boxmodel-size > span");
   is(sizeElt.textContent, "100\u00D7100");
 
   info("Listening for box model view changes and modifying its size");
diff --git a/devtools/client/inspector/components/test/doc_boxmodel_iframe1.html b/devtools/client/inspector/boxmodel/test/doc_boxmodel_iframe1.html
similarity index 100%
rename from devtools/client/inspector/components/test/doc_boxmodel_iframe1.html
rename to devtools/client/inspector/boxmodel/test/doc_boxmodel_iframe1.html
diff --git a/devtools/client/inspector/components/test/doc_boxmodel_iframe2.html b/devtools/client/inspector/boxmodel/test/doc_boxmodel_iframe2.html
similarity index 100%
rename from devtools/client/inspector/components/test/doc_boxmodel_iframe2.html
rename to devtools/client/inspector/boxmodel/test/doc_boxmodel_iframe2.html
diff --git a/devtools/client/inspector/components/test/head.js b/devtools/client/inspector/boxmodel/test/head.js
similarity index 55%
rename from devtools/client/inspector/components/test/head.js
rename to devtools/client/inspector/boxmodel/test/head.js
index fa86b5e9e179..b842968a5595 100644
--- a/devtools/client/inspector/components/test/head.js
+++ b/devtools/client/inspector/boxmodel/test/head.js
@@ -19,12 +19,13 @@ registerCleanupFunction(() => {
 /**
  * Highlight a node and set the inspector's current selection to the node or
  * the first match of the given css selector.
- * @param {String|NodeFront} selectorOrNodeFront
- *        The selector for the node to be set, or the nodeFront
- * @param {InspectorPanel} inspector
- *        The instance of InspectorPanel currently loaded in the toolbox
- * @return a promise that resolves when the inspector is updated with the new
- * node
+ *
+ * @param  {String|NodeFront} selectorOrNodeFront
+ *         The selector for the node to be set, or the nodeFront.
+ * @param  {InspectorPanel} inspector
+ *         The instance of InspectorPanel currently loaded in the toolbox.
+ * @return {Promise} a promise that resolves when the inspector is updated with the new
+ *         node.
  */
 function* selectAndHighlightNode(selectorOrNodeFront, inspector) {
   info("Highlighting and selecting the node " + selectorOrNodeFront);
@@ -38,8 +39,9 @@ function* selectAndHighlightNode(selectorOrNodeFront, inspector) {
 /**
  * Open the toolbox, with the inspector tool visible, and the computed view
  * sidebar tab selected to display the box model view.
- * @return a promise that resolves when the inspector is ready and the box model
- * view is visible and ready
+ *
+ * @return {Promise} a promise that resolves when the inspector is ready and the box model
+ *         view is visible and ready.
  */
 function openBoxModelView() {
   return openInspectorSidebarTab("computedview").then(data => {
@@ -58,7 +60,7 @@ function openBoxModelView() {
     return {
       toolbox: data.toolbox,
       inspector: data.inspector,
-      view: data.inspector.computedview.boxModelView,
+      view: data.inspector.computedview,
       testActor: data.testActor
     };
   });
@@ -66,10 +68,37 @@ function openBoxModelView() {
 
 /**
  * Wait for the boxmodel-view-updated event.
- * @return a promise
+ *
+ * @param  {InspectorPanel} inspector
+ *         The instance of InspectorPanel currently loaded in the toolbox.
+ * @param  {Boolean} waitForSelectionUpdate
+ *         Should the boxmodel-view-updated event come from a new selection.
+ * @return {Promise} a promise
  */
-function waitForUpdate(inspector) {
-  return inspector.once("boxmodel-view-updated");
+function waitForUpdate(inspector, waitForSelectionUpdate) {
+  return new Promise(resolve => {
+    inspector.on("boxmodel-view-updated", function onUpdate(e, reasons) {
+      // Wait for another update event if we are waiting for a selection related event.
+      if (waitForSelectionUpdate && !reasons.includes("new-selection")) {
+        return;
+      }
+
+      inspector.off("boxmodel-view-updated", onUpdate);
+      resolve();
+    });
+  });
+}
+
+/**
+ * Wait for both boxmode-view-updated and markuploaded events.
+ *
+ * @return {Promise} a promise that resolves when both events have been received.
+ */
+function waitForMarkupLoaded(inspector) {
+  return Promise.all([
+    waitForUpdate(inspector),
+    inspector.once("markuploaded"),
+  ]);
 }
 
 function getStyle(testActor, selector, propertyName) {
@@ -85,3 +114,15 @@ function setStyle(testActor, selector, propertyName, value) {
                     .style.${propertyName} = "${value}";
   `);
 }
+
+/**
+ * The box model doesn't participate in the inspector's update mechanism, so simply
+ * calling the default selectNode isn't enough to guarantee that the box model view has
+ * finished updating. We also need to wait for the "boxmodel-view-updated" event.
+ */
+var _selectNode = selectNode;
+selectNode = function* (node, inspector, reason) {
+  let onUpdate = waitForUpdate(inspector, true);
+  yield _selectNode(node, inspector, reason);
+  yield onUpdate;
+};
diff --git a/devtools/client/inspector/boxmodel/types.js b/devtools/client/inspector/boxmodel/types.js
new file mode 100644
index 000000000000..aba8f7893d7e
--- /dev/null
+++ b/devtools/client/inspector/boxmodel/types.js
@@ -0,0 +1,17 @@
+/* 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 { PropTypes } = require("devtools/client/shared/vendor/react");
+
+/**
+ * The box model data for the current selected node.
+ */
+exports.boxModel = {
+
+  // The layout information of the current selected node
+  layout: PropTypes.object,
+
+};
diff --git a/devtools/client/inspector/layout/utils/editing-session.js b/devtools/client/inspector/boxmodel/utils/editing-session.js
similarity index 100%
rename from devtools/client/inspector/layout/utils/editing-session.js
rename to devtools/client/inspector/boxmodel/utils/editing-session.js
diff --git a/devtools/client/inspector/boxmodel/utils/moz.build b/devtools/client/inspector/boxmodel/utils/moz.build
new file mode 100644
index 000000000000..4ad6c32d9ef5
--- /dev/null
+++ b/devtools/client/inspector/boxmodel/utils/moz.build
@@ -0,0 +1,9 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+DevToolsModules(
+    'editing-session.js',
+)
diff --git a/devtools/client/inspector/components/deprecated-box-model.js b/devtools/client/inspector/components/deprecated-box-model.js
deleted file mode 100644
index 874a79939c97..000000000000
--- a/devtools/client/inspector/components/deprecated-box-model.js
+++ /dev/null
@@ -1,912 +0,0 @@
-/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* vim: set ft=javascript ts=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/. */
-
-/**
- * THIS MODULE IS DEPRECATED.
- *
- * To continue any work related to the box model view, see the new react/redux
- * implementation in devtools/client/inspector/layout/.
- */
-
-"use strict";
-
-const {Task} = require("devtools/shared/task");
-const {InplaceEditor, editableItem} =
-      require("devtools/client/shared/inplace-editor");
-const {ReflowFront} = require("devtools/shared/fronts/reflow");
-const {LocalizationHelper} = require("devtools/shared/l10n");
-const {getCssProperties} = require("devtools/shared/fronts/css-properties");
-const {KeyCodes} = require("devtools/client/shared/keycodes");
-const EditingSession = require("devtools/client/inspector/layout/utils/editing-session");
-
-const STRINGS_URI = "devtools/client/locales/shared.properties";
-const STRINGS_INSPECTOR = "devtools/shared/locales/styleinspector.properties";
-const SHARED_L10N = new LocalizationHelper(STRINGS_URI);
-const INSPECTOR_L10N = new LocalizationHelper(STRINGS_INSPECTOR);
-const NUMERIC = /^-?[\d\.]+$/;
-const LONG_TEXT_ROTATE_LIMIT = 3;
-
-/**
- * The box model view
- * @param {InspectorPanel} inspector
- *        An instance of the inspector-panel currently loaded in the toolbox
- * @param {Document} document
- *        The document that will contain the box model view.
- */
-function BoxModelView(inspector, document) {
-  this.inspector = inspector;
-  this.doc = document;
-  this.wrapper = this.doc.getElementById("old-boxmodel-wrapper");
-  this.container = this.doc.getElementById("old-boxmodel-container");
-  this.expander = this.doc.getElementById("old-boxmodel-expander");
-  this.sizeLabel = this.doc.querySelector(".old-boxmodel-size > span");
-  this.sizeHeadingLabel = this.doc.getElementById("old-boxmodel-element-size");
-  this._geometryEditorHighlighter = null;
-  this._cssProperties = getCssProperties(inspector.toolbox);
-
-  this.init();
-}
-
-BoxModelView.prototype = {
-  init: function () {
-    this.update = this.update.bind(this);
-
-    this.onNewSelection = this.onNewSelection.bind(this);
-    this.inspector.selection.on("new-node-front", this.onNewSelection);
-
-    this.onNewNode = this.onNewNode.bind(this);
-    this.inspector.sidebar.on("computedview-selected", this.onNewNode);
-
-    this.onSidebarSelect = this.onSidebarSelect.bind(this);
-    this.inspector.sidebar.on("select", this.onSidebarSelect);
-
-    this.onToggleExpander = this.onToggleExpander.bind(this);
-    this.expander.addEventListener("click", this.onToggleExpander);
-    let header = this.doc.getElementById("old-boxmodel-header");
-    header.addEventListener("dblclick", this.onToggleExpander);
-
-    this.onFilterComputedView = this.onFilterComputedView.bind(this);
-    this.inspector.on("computed-view-filtered",
-      this.onFilterComputedView);
-
-    this.onPickerStarted = this.onPickerStarted.bind(this);
-    this.onMarkupViewLeave = this.onMarkupViewLeave.bind(this);
-    this.onMarkupViewNodeHover = this.onMarkupViewNodeHover.bind(this);
-    this.onWillNavigate = this.onWillNavigate.bind(this);
-    this.onKeyDown = this.onKeyDown.bind(this);
-    this.onLevelClick = this.onLevelClick.bind(this);
-    this.setAriaActive = this.setAriaActive.bind(this);
-    this.getEditBoxes = this.getEditBoxes.bind(this);
-    this.makeFocusable = this.makeFocusable.bind(this);
-    this.makeUnfocasable = this.makeUnfocasable.bind(this);
-    this.moveFocus = this.moveFocus.bind(this);
-    this.onFocus = this.onFocus.bind(this);
-
-    this.borderLayout = this.doc.getElementById("old-boxmodel-borders");
-    this.boxModel = this.doc.getElementById("old-boxmodel-wrapper");
-    this.marginLayout = this.doc.getElementById("old-boxmodel-margins");
-    this.paddingLayout = this.doc.getElementById("old-boxmodel-padding");
-
-    this.layouts = {
-      "margin": new Map([
-        [KeyCodes.DOM_VK_ESCAPE, this.marginLayout],
-        [KeyCodes.DOM_VK_DOWN, this.borderLayout],
-        [KeyCodes.DOM_VK_UP, null],
-        ["click", this.marginLayout]
-      ]),
-      "border": new Map([
-        [KeyCodes.DOM_VK_ESCAPE, this.borderLayout],
-        [KeyCodes.DOM_VK_DOWN, this.paddingLayout],
-        [KeyCodes.DOM_VK_UP, this.marginLayout],
-        ["click", this.borderLayout]
-      ]),
-      "padding": new Map([
-        [KeyCodes.DOM_VK_ESCAPE, this.paddingLayout],
-        [KeyCodes.DOM_VK_DOWN, null],
-        [KeyCodes.DOM_VK_UP, this.borderLayout],
-        ["click", this.paddingLayout]
-      ])
-    };
-
-    this.boxModel.addEventListener("click", this.onLevelClick, true);
-    this.boxModel.addEventListener("focus", this.onFocus, true);
-    this.boxModel.addEventListener("keydown", this.onKeyDown, true);
-
-    this.initBoxModelHighlighter();
-
-    // Store for the different dimensions of the node.
-    // 'selector' refers to the element that holds the value;
-    // 'property' is what we are measuring;
-    // 'value' is the computed dimension, computed in update().
-    this.map = {
-      position: {
-        selector: "#old-boxmodel-element-position",
-        property: "position",
-        value: undefined
-      },
-      marginTop: {
-        selector: ".old-boxmodel-margin.old-boxmodel-top > span",
-        property: "margin-top",
-        value: undefined
-      },
-      marginBottom: {
-        selector: ".old-boxmodel-margin.old-boxmodel-bottom > span",
-        property: "margin-bottom",
-        value: undefined
-      },
-      marginLeft: {
-        selector: ".old-boxmodel-margin.old-boxmodel-left > span",
-        property: "margin-left",
-        value: undefined
-      },
-      marginRight: {
-        selector: ".old-boxmodel-margin.old-boxmodel-right > span",
-        property: "margin-right",
-        value: undefined
-      },
-      paddingTop: {
-        selector: ".old-boxmodel-padding.old-boxmodel-top > span",
-        property: "padding-top",
-        value: undefined
-      },
-      paddingBottom: {
-        selector: ".old-boxmodel-padding.old-boxmodel-bottom > span",
-        property: "padding-bottom",
-        value: undefined
-      },
-      paddingLeft: {
-        selector: ".old-boxmodel-padding.old-boxmodel-left > span",
-        property: "padding-left",
-        value: undefined
-      },
-      paddingRight: {
-        selector: ".old-boxmodel-padding.old-boxmodel-right > span",
-        property: "padding-right",
-        value: undefined
-      },
-      borderTop: {
-        selector: ".old-boxmodel-border.old-boxmodel-top > span",
-        property: "border-top-width",
-        value: undefined
-      },
-      borderBottom: {
-        selector: ".old-boxmodel-border.old-boxmodel-bottom > span",
-        property: "border-bottom-width",
-        value: undefined
-      },
-      borderLeft: {
-        selector: ".old-boxmodel-border.old-boxmodel-left > span",
-        property: "border-left-width",
-        value: undefined
-      },
-      borderRight: {
-        selector: ".old-boxmodel-border.old-boxmodel-right > span",
-        property: "border-right-width",
-        value: undefined
-      }
-    };
-
-    // Make each element the dimensions editable
-    for (let i in this.map) {
-      if (i == "position") {
-        continue;
-      }
-
-      let dimension = this.map[i];
-      editableItem({
-        element: this.doc.querySelector(dimension.selector)
-      }, (element, event) => {
-        this.initEditor(element, event, dimension);
-      });
-    }
-
-    this.onNewNode();
-
-    let nodeGeometry = this.doc.getElementById("old-layout-geometry-editor");
-    this.onGeometryButtonClick = this.onGeometryButtonClick.bind(this);
-    nodeGeometry.addEventListener("click", this.onGeometryButtonClick);
-  },
-
-  initBoxModelHighlighter: function () {
-    let highlightElts = this.doc.querySelectorAll("#old-boxmodel-container *[title]");
-    this.onHighlightMouseOver = this.onHighlightMouseOver.bind(this);
-    this.onHighlightMouseOut = this.onHighlightMouseOut.bind(this);
-
-    for (let element of highlightElts) {
-      element.addEventListener("mouseover", this.onHighlightMouseOver, true);
-      element.addEventListener("mouseout", this.onHighlightMouseOut, true);
-    }
-  },
-
-  /**
-   * Start listening to reflows in the current tab.
-   */
-  trackReflows: function () {
-    if (!this.reflowFront) {
-      let { target } = this.inspector;
-      if (target.form.reflowActor) {
-        this.reflowFront = ReflowFront(target.client,
-                                       target.form);
-      } else {
-        return;
-      }
-    }
-
-    this.reflowFront.on("reflows", this.update);
-    this.reflowFront.start();
-  },
-
-  /**
-   * Stop listening to reflows in the current tab.
-   */
-  untrackReflows: function () {
-    if (!this.reflowFront) {
-      return;
-    }
-
-    this.reflowFront.off("reflows", this.update);
-    this.reflowFront.stop();
-  },
-
-  /**
-   * Called when the user clicks on one of the editable values in the box model view
-   */
-  initEditor: function (element, event, dimension) {
-    let { property } = dimension;
-    let session = new EditingSession(this);
-    let initialValue = session.getProperty(property);
-
-    let editor = new InplaceEditor({
-      element: element,
-      initial: initialValue,
-      contentType: InplaceEditor.CONTENT_TYPES.CSS_VALUE,
-      property: {
-        name: dimension.property
-      },
-      start: self => {
-        self.elt.parentNode.classList.add("old-boxmodel-editing");
-      },
-      change: value => {
-        if (NUMERIC.test(value)) {
-          value += "px";
-        }
-
-        let properties = [
-          { name: property, value: value }
-        ];
-
-        if (property.substring(0, 7) == "border-") {
-          let bprop = property.substring(0, property.length - 5) + "style";
-          let style = session.getProperty(bprop);
-          if (!style || style == "none" || style == "hidden") {
-            properties.push({ name: bprop, value: "solid" });
-          }
-        }
-
-        session.setProperties(properties).catch(e => console.error(e));
-      },
-      done: (value, commit) => {
-        editor.elt.parentNode.classList.remove("old-boxmodel-editing");
-        if (!commit) {
-          session.revert().then(() => {
-            session.destroy();
-          }, e => console.error(e));
-        }
-      },
-      contextMenu: this.inspector.onTextBoxContextMenu,
-      cssProperties: this._cssProperties
-    }, event);
-  },
-
-  /**
-   * Is the BoxModelView visible in the sidebar.
-   * @return {Boolean}
-   */
-  isViewVisible: function () {
-    return this.inspector &&
-           this.inspector.sidebar.getCurrentTabID() == "computedview";
-  },
-
-  /**
-   * Is the BoxModelView visible in the sidebar and is the current node valid to
-   * be displayed in the view.
-   * @return {Boolean}
-   */
-  isViewVisibleAndNodeValid: function () {
-    return this.isViewVisible() &&
-           this.inspector.selection.isConnected() &&
-           this.inspector.selection.isElementNode();
-  },
-
-  /**
-   * Destroy the nodes. Remove listeners.
-   */
-  destroy: function () {
-    let highlightElts = this.doc.querySelectorAll("#old-boxmodel-container *[title]");
-
-    for (let element of highlightElts) {
-      element.removeEventListener("mouseover", this.onHighlightMouseOver, true);
-      element.removeEventListener("mouseout", this.onHighlightMouseOut, true);
-    }
-
-    this.expander.removeEventListener("click", this.onToggleExpander);
-    let header = this.doc.getElementById("old-boxmodel-header");
-    header.removeEventListener("dblclick", this.onToggleExpander);
-
-    let nodeGeometry = this.doc.getElementById("old-layout-geometry-editor");
-    nodeGeometry.removeEventListener("click", this.onGeometryButtonClick);
-
-    this.boxModel.removeEventListener("click", this.onLevelClick, true);
-    this.boxModel.removeEventListener("focus", this.onFocus, true);
-    this.boxModel.removeEventListener("keydown", this.onKeyDown, true);
-
-    this.inspector.off("picker-started", this.onPickerStarted);
-
-    // Inspector Panel will destroy `markup` object on "will-navigate" event,
-    // therefore we have to check if it's still available in case BoxModelView
-    // is destroyed immediately after.
-    if (this.inspector.markup) {
-      this.inspector.markup.off("leave", this.onMarkupViewLeave);
-      this.inspector.markup.off("node-hover", this.onMarkupViewNodeHover);
-    }
-
-    this.inspector.sidebar.off("computedview-selected", this.onNewNode);
-    this.inspector.selection.off("new-node-front", this.onNewSelection);
-    this.inspector.sidebar.off("select", this.onSidebarSelect);
-    this.inspector.target.off("will-navigate", this.onWillNavigate);
-    this.inspector.off("computed-view-filtered", this.onFilterComputedView);
-
-    this.inspector = null;
-    this.doc = null;
-    this.wrapper = null;
-    this.container = null;
-    this.expander = null;
-    this.sizeLabel = null;
-    this.sizeHeadingLabel = null;
-
-    this.marginLayout = null;
-    this.borderLayout = null;
-    this.paddingLayout = null;
-    this.boxModel = null;
-    this.layouts = null;
-
-    if (this.reflowFront) {
-      this.untrackReflows();
-      this.reflowFront.destroy();
-      this.reflowFront = null;
-    }
-  },
-
-  /**
-   * Set initial box model focus to the margin layout.
-   */
-  onFocus: function () {
-    let activeDescendant = this.boxModel.getAttribute("aria-activedescendant");
-
-    if (!activeDescendant) {
-      let nextLayout = this.marginLayout;
-      this.setAriaActive(nextLayout);
-    }
-  },
-
-  /**
-   * Active aria-level set to current layout.
-   *
-   * @param {Element} nextLayout
-   *        Element of next layout that user has navigated to
-   * @param {Node} target
-   *        Node to be observed
-   */
-  setAriaActive: function (nextLayout, target) {
-    this.boxModel.setAttribute("aria-activedescendant", nextLayout.id);
-    if (target && target._editable) {
-      target.blur();
-    }
-
-    // Clear all
-    this.marginLayout.classList.remove("layout-active-elm");
-    this.borderLayout.classList.remove("layout-active-elm");
-    this.paddingLayout.classList.remove("layout-active-elm");
-
-    // Set the next level's border outline
-    nextLayout.classList.add("layout-active-elm");
-  },
-
-  /**
-   * Update aria-active on mouse click.
-   *
-   * @param {Event} event
-   *         The event triggered by a mouse click on the box model
-   */
-  onLevelClick: function (event) {
-    let {target} = event;
-    let nextLayout = this.layouts[target.getAttribute("data-box")].get("click");
-
-    this.setAriaActive(nextLayout, target);
-  },
-
-  /**
-   * Handle keyboard navigation and focus for box model layouts.
-   *
-   * Updates active layout on arrow key navigation
-   * Focuses next layout's editboxes on enter key
-   * Unfocuses current layout's editboxes when active layout changes
-   * Controls tabbing between editBoxes
-   *
-   * @param {Event} event
-   *         The event triggered by a keypress on the box model
-   */
-  onKeyDown: function (event) {
-    let {target, keyCode} = event;
-    // If focused on editable value or in editing mode
-    let isEditable = target._editable || target.editor;
-    let level = this.boxModel.getAttribute("aria-activedescendant");
-    let editingMode = target.tagName === "input";
-    let nextLayout;
-
-    switch (keyCode) {
-      case KeyCodes.DOM_VK_RETURN:
-        if (!isEditable) {
-          this.makeFocusable(level);
-        }
-        break;
-      case KeyCodes.DOM_VK_DOWN:
-      case KeyCodes.DOM_VK_UP:
-        if (!editingMode) {
-          event.preventDefault();
-          this.makeUnfocasable(level);
-          let datalevel = this.doc.getElementById(level).getAttribute("data-box");
-          nextLayout = this.layouts[datalevel].get(keyCode);
-          this.boxModel.focus();
-        }
-        break;
-      case KeyCodes.DOM_VK_TAB:
-        if (isEditable) {
-          event.preventDefault();
-          this.moveFocus(event, level);
-        }
-        break;
-      case KeyCodes.DOM_VK_ESCAPE:
-        if (isEditable && target._editable) {
-          event.preventDefault();
-          event.stopPropagation();
-          this.makeUnfocasable(level);
-          this.boxModel.focus();
-        }
-        break;
-      default:
-        break;
-    }
-
-    if (nextLayout) {
-      this.setAriaActive(nextLayout, target);
-    }
-  },
-
-  /**
-   * Make previous layout's elements unfocusable.
-   *
-   * @param {String} editLevel
-   *        The previous layout
-   */
-  makeUnfocasable: function (editLevel) {
-    let editBoxes = this.getEditBoxes(editLevel);
-    editBoxes.forEach(editBox => editBox.setAttribute("tabindex", "-1"));
-  },
-
-  /**
-   * Make current layout's elements focusable.
-   *
-   * @param {String} editLevel
-   *        The current layout
-   */
-  makeFocusable: function (editLevel) {
-    let editBoxes = this.getEditBoxes(editLevel);
-    editBoxes.forEach(editBox => editBox.setAttribute("tabindex", "0"));
-    editBoxes[0].focus();
-  },
-
-  /**
-   * Keyboard navigation of edit boxes wraps around on edge
-   * elements ([layout]-top, [layout]-left).
-   *
-   * @param {Node} target
-   *        Node to be observed
-   * @param {Boolean} shiftKey
-   *        Determines if shiftKey was pressed
-   * @param {String} level
-   *        Current active layout
-   */
-  moveFocus: function ({target, shiftKey}, level) {
-    let editBoxes = this.getEditBoxes(level);
-    let editingMode = target.tagName === "input";
-    // target.nextSibling is input field
-    let position = editingMode ? editBoxes.indexOf(target.nextSibling)
-                               : editBoxes.indexOf(target);
-
-    if (position === editBoxes.length - 1 && !shiftKey) {
-      position = 0;
-    } else if (position === 0 && shiftKey) {
-      position = editBoxes.length - 1;
-    } else {
-      shiftKey ? position-- : position++;
-    }
-
-    let editBox = editBoxes[position];
-    editBox.focus();
-
-    if (editingMode) {
-      editBox.click();
-    }
-  },
-
-  /**
-   * Retrieve edit boxes for current layout.
-   *
-   * @param {String} editLevel
-   *        Current active layout
-   * @return Layout's edit boxes
-   */
-  getEditBoxes: function (editLevel) {
-    let dataLevel = this.doc.getElementById(editLevel).getAttribute("data-box");
-    return [...this.doc.querySelectorAll(
-      `[data-box="${dataLevel}"].old-boxmodel-editable`)];
-  },
-
-  onSidebarSelect: function (e, sidebar) {
-    this.setActive(sidebar === "computedview");
-  },
-
-  /**
-   * Selection 'new-node-front' event handler.
-   */
-  onNewSelection: function () {
-    let done = this.inspector.updating("computed-view");
-    this.onNewNode()
-      .then(() => this.hideGeometryEditor())
-      .then(done, (err) => {
-        console.error(err);
-        done();
-      }).catch(console.error);
-  },
-
-  /**
-   * @return a promise that resolves when the view has been updated
-   */
-  onNewNode: function () {
-    this.setActive(this.isViewVisibleAndNodeValid());
-    return this.update();
-  },
-
-  onHighlightMouseOver: function (e) {
-    let region = e.target.getAttribute("data-box");
-    if (!region) {
-      return;
-    }
-
-    this.showBoxModel({
-      region,
-      showOnly: region,
-      onlyRegionArea: true
-    });
-  },
-
-  onHighlightMouseOut: function () {
-    this.hideBoxModel();
-  },
-
-  onGeometryButtonClick: function ({target}) {
-    if (target.hasAttribute("checked")) {
-      target.removeAttribute("checked");
-      this.hideGeometryEditor();
-    } else {
-      target.setAttribute("checked", "true");
-      this.showGeometryEditor();
-    }
-  },
-
-  onPickerStarted: function () {
-    this.hideGeometryEditor();
-  },
-
-  onToggleExpander: function () {
-    let isOpen = this.expander.hasAttribute("open");
-
-    if (isOpen) {
-      this.container.hidden = true;
-      this.expander.removeAttribute("open");
-    } else {
-      this.container.hidden = false;
-      this.expander.setAttribute("open", "");
-    }
-  },
-
-  onMarkupViewLeave: function () {
-    this.showGeometryEditor(true);
-  },
-
-  onMarkupViewNodeHover: function () {
-    this.hideGeometryEditor(false);
-  },
-
-  onWillNavigate: function () {
-    this._geometryEditorHighlighter.release().catch(console.error);
-    this._geometryEditorHighlighter = null;
-  },
-
-  /**
-   * Event handler that responds to the computed view being filtered
-   * @param {String} reason
-   * @param {Boolean} hidden
-   *        Whether or not to hide the box model wrapper
-   */
-  onFilterComputedView: function (reason, hidden) {
-    this.wrapper.hidden = hidden;
-  },
-
-  /**
-   * Stop tracking reflows and hide all values when no node is selected or the
-   * box model view is hidden, otherwise track reflows and show values.
-   * @param {Boolean} isActive
-   */
-  setActive: function (isActive) {
-    if (isActive === this.isActive) {
-      return;
-    }
-    this.isActive = isActive;
-
-    if (isActive) {
-      this.trackReflows();
-    } else {
-      this.untrackReflows();
-    }
-  },
-
-  /**
-   * Compute the dimensions of the node and update the values in
-   * the inspector.xul document.
-   * @return a promise that will be resolved when complete.
-   */
-  update: function () {
-    let lastRequest = Task.spawn((function* () {
-      if (!this.isViewVisibleAndNodeValid()) {
-        this.wrapper.hidden = true;
-        this.inspector.emit("boxmodel-view-updated");
-        return null;
-      }
-
-      let node = this.inspector.selection.nodeFront;
-      let layout = yield this.inspector.pageStyle.getLayout(node, {
-        autoMargins: this.isActive
-      });
-      let styleEntries = yield this.inspector.pageStyle.getApplied(node, {});
-
-      yield this.updateGeometryButton();
-
-      // If a subsequent request has been made, wait for that one instead.
-      if (this._lastRequest != lastRequest) {
-        return this._lastRequest;
-      }
-
-      this._lastRequest = null;
-      let width = layout.width;
-      let height = layout.height;
-      let newLabel = SHARED_L10N.getFormatStr("dimensions", width, height);
-
-      if (this.sizeHeadingLabel.textContent != newLabel) {
-        this.sizeHeadingLabel.textContent = newLabel;
-      }
-
-      for (let i in this.map) {
-        let property = this.map[i].property;
-        if (!(property in layout)) {
-          // Depending on the actor version, some properties
-          // might be missing.
-          continue;
-        }
-        let parsedValue = parseFloat(layout[property]);
-        if (Number.isNaN(parsedValue)) {
-          // Not a number. We use the raw string.
-          // Useful for "position" for example.
-          this.map[i].value = layout[property];
-        } else {
-          this.map[i].value = parsedValue;
-        }
-      }
-
-      let margins = layout.autoMargins;
-      if ("top" in margins) {
-        this.map.marginTop.value = "auto";
-      }
-      if ("right" in margins) {
-        this.map.marginRight.value = "auto";
-      }
-      if ("bottom" in margins) {
-        this.map.marginBottom.value = "auto";
-      }
-      if ("left" in margins) {
-        this.map.marginLeft.value = "auto";
-      }
-
-      for (let i in this.map) {
-        let selector = this.map[i].selector;
-        let span = this.doc.querySelector(selector);
-        this.updateSourceRuleTooltip(span, this.map[i].property, styleEntries);
-        if (span.textContent.length > 0 &&
-            span.textContent == this.map[i].value) {
-          continue;
-        }
-        span.textContent = this.map[i].value;
-        this.manageOverflowingText(span);
-      }
-
-      width -= this.map.borderLeft.value + this.map.borderRight.value +
-               this.map.paddingLeft.value + this.map.paddingRight.value;
-      width = parseFloat(width.toPrecision(6));
-      height -= this.map.borderTop.value + this.map.borderBottom.value +
-                this.map.paddingTop.value + this.map.paddingBottom.value;
-      height = parseFloat(height.toPrecision(6));
-
-      let newValue = width + "\u00D7" + height;
-      if (this.sizeLabel.textContent != newValue) {
-        this.sizeLabel.textContent = newValue;
-      }
-
-      this.elementRules = styleEntries.map(e => e.rule);
-
-      this.wrapper.hidden = false;
-
-      this.inspector.emit("boxmodel-view-updated");
-      return null;
-    }).bind(this)).catch(console.error);
-
-    this._lastRequest = lastRequest;
-    return this._lastRequest;
-  },
-
-  /**
-   * Update the text in the tooltip shown when hovering over a value to provide
-   * information about the source CSS rule that sets this value.
-   * @param {DOMNode} el The element that will receive the tooltip.
-   * @param {String} property The name of the CSS property for the tooltip.
-   * @param {Array} rules An array of applied rules retrieved by
-   * styleActor.getApplied.
-   */
-  updateSourceRuleTooltip: function (el, property, rules) {
-    // Dummy element used to parse the cssText of applied rules.
-    let dummyEl = this.doc.createElement("div");
-
-    // Rules are in order of priority so iterate until we find the first that
-    // defines a value for the property.
-    let sourceRule, value;
-    for (let {rule} of rules) {
-      dummyEl.style.cssText = rule.cssText;
-      value = dummyEl.style.getPropertyValue(property);
-      if (value !== "") {
-        sourceRule = rule;
-        break;
-      }
-    }
-
-    let title = property;
-    if (sourceRule && sourceRule.selectors) {
-      title += "\n" + sourceRule.selectors.join(", ");
-    }
-    if (sourceRule && sourceRule.parentStyleSheet) {
-      if (sourceRule.parentStyleSheet.href) {
-        title += "\n" + sourceRule.parentStyleSheet.href + ":" + sourceRule.line;
-      } else {
-        title += "\n" + INSPECTOR_L10N.getStr("rule.sourceInline") +
-          ":" + sourceRule.line;
-      }
-    }
-
-    el.setAttribute("title", title);
-  },
-
-  /**
-   * Show the box-model highlighter on the currently selected element
-   * @param {Object} options Options passed to the highlighter actor
-   */
-  showBoxModel: function (options = {}) {
-    let toolbox = this.inspector.toolbox;
-    let nodeFront = this.inspector.selection.nodeFront;
-
-    toolbox.highlighterUtils.highlightNodeFront(nodeFront, options);
-  },
-
-  /**
-   * Hide the box-model highlighter on the currently selected element
-   */
-  hideBoxModel: function () {
-    let toolbox = this.inspector.toolbox;
-
-    toolbox.highlighterUtils.unhighlight();
-  },
-
-  /**
-   * Show the geometry editor highlighter on the currently selected element
-   * @param {Boolean} [showOnlyIfActive=false]
-   *   Indicates if the Geometry Editor should be shown only if it's active but
-   *   hidden.
-   */
-  showGeometryEditor: function (showOnlyIfActive = false) {
-    let toolbox = this.inspector.toolbox;
-    let nodeFront = this.inspector.selection.nodeFront;
-    let nodeGeometry = this.doc.getElementById("old-layout-geometry-editor");
-    let isActive = nodeGeometry.hasAttribute("checked");
-
-    if (showOnlyIfActive && !isActive) {
-      return;
-    }
-
-    if (this._geometryEditorHighlighter) {
-      this._geometryEditorHighlighter.show(nodeFront).catch(console.error);
-      return;
-    }
-
-    // instantiate Geometry Editor highlighter
-    toolbox.highlighterUtils
-      .getHighlighterByType("GeometryEditorHighlighter").then(highlighter => {
-        highlighter.show(nodeFront).catch(console.error);
-        this._geometryEditorHighlighter = highlighter;
-
-        // Hide completely the geometry editor if the picker is clicked
-        toolbox.on("picker-started", this.onPickerStarted);
-
-        // Temporary hide the geometry editor
-        this.inspector.markup.on("leave", this.onMarkupViewLeave);
-        this.inspector.markup.on("node-hover", this.onMarkupViewNodeHover);
-
-        // Release the actor on will-navigate event
-        this.inspector.target.once("will-navigate", this.onWillNavigate);
-      });
-  },
-
-  /**
-   * Hide the geometry editor highlighter on the currently selected element
-   * @param {Boolean} [updateButton=true]
-   *   Indicates if the Geometry Editor's button needs to be unchecked too
-   */
-  hideGeometryEditor: function (updateButton = true) {
-    if (this._geometryEditorHighlighter) {
-      this._geometryEditorHighlighter.hide().catch(console.error);
-    }
-
-    if (updateButton) {
-      let nodeGeometry = this.doc.getElementById("old-layout-geometry-editor");
-      nodeGeometry.removeAttribute("checked");
-    }
-  },
-
-  /**
-   * Update the visibility and the state of the geometry editor button,
-   * based on the selected node.
-   */
-  updateGeometryButton: Task.async(function* () {
-    let node = this.inspector.selection.nodeFront;
-    let isEditable = false;
-
-    if (node) {
-      isEditable = yield this.inspector.pageStyle.isPositionEditable(node);
-    }
-
-    let nodeGeometry = this.doc.getElementById("old-layout-geometry-editor");
-    nodeGeometry.style.visibility = isEditable ? "visible" : "hidden";
-  }),
-
-  manageOverflowingText: function (span) {
-    let classList = span.parentNode.classList;
-
-    if (classList.contains("old-boxmodel-left") ||
-        classList.contains("old-boxmodel-right")) {
-      let force = span.textContent.length > LONG_TEXT_ROTATE_LIMIT;
-      classList.toggle("old-boxmodel-rotate", force);
-    }
-  }
-};
-
-module.exports = BoxModelView;
diff --git a/devtools/client/inspector/components/moz.build b/devtools/client/inspector/components/moz.build
index 23d85edcdb23..50556cf26ecf 100644
--- a/devtools/client/inspector/components/moz.build
+++ b/devtools/client/inspector/components/moz.build
@@ -5,9 +5,6 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DevToolsModules(
-    'deprecated-box-model.js',
     'inspector-tab-panel.css',
     'inspector-tab-panel.js',
 )
-
-BROWSER_CHROME_MANIFESTS += ['test/browser.ini']
diff --git a/devtools/client/inspector/components/test/browser_boxmodel_rotate-labels-on-sides.js b/devtools/client/inspector/components/test/browser_boxmodel_rotate-labels-on-sides.js
deleted file mode 100644
index df667e6d1a55..000000000000
--- a/devtools/client/inspector/components/test/browser_boxmodel_rotate-labels-on-sides.js
+++ /dev/null
@@ -1,49 +0,0 @@
-/* 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";
-
-// Test that longer values are rotated on the side
-
-const res1 = [
-  {selector: ".old-boxmodel-margin.old-boxmodel-top > span", value: 30},
-  {selector: ".old-boxmodel-margin.old-boxmodel-left > span", value: "auto"},
-  {selector: ".old-boxmodel-margin.old-boxmodel-bottom > span", value: 30},
-  {selector: ".old-boxmodel-margin.old-boxmodel-right > span", value: "auto"},
-  {selector: ".old-boxmodel-padding.old-boxmodel-top > span", value: 20},
-  {selector: ".old-boxmodel-padding.old-boxmodel-left > span", value: 2000000},
-  {selector: ".old-boxmodel-padding.old-boxmodel-bottom > span", value: 20},
-  {selector: ".old-boxmodel-padding.old-boxmodel-right > span", value: 20},
-  {selector: ".old-boxmodel-border.old-boxmodel-top > span", value: 10},
-  {selector: ".old-boxmodel-border.old-boxmodel-left > span", value: 10},
-  {selector: ".old-boxmodel-border.old-boxmodel-bottom > span", value: 10},
-  {selector: ".old-boxmodel-border.old-boxmodel-right > span", value: 10},
-];
-
-const TEST_URI = encodeURIComponent([
-  "<style>",
-  "div { border:10px solid black; padding: 20px 20px 20px 2000000px; " +
-  "margin: 30px auto; }",
-  "</style>",
-  "<div></div>"
-].join(""));
-const LONG_TEXT_ROTATE_LIMIT = 3;
-
-add_task(function* () {
-  yield addTab("data:text/html," + TEST_URI);
-  let {inspector, view} = yield openBoxModelView();
-  yield selectNode("div", inspector);
-
-  for (let i = 0; i < res1.length; i++) {
-    let elt = view.doc.querySelector(res1[i].selector);
-    let isLong = elt.textContent.length > LONG_TEXT_ROTATE_LIMIT;
-    let classList = elt.parentNode.classList;
-    let canBeRotated = classList.contains("old-boxmodel-left") ||
-                       classList.contains("old-boxmodel-right");
-    let isRotated = classList.contains("old-boxmodel-rotate");
-
-    is(canBeRotated && isLong,
-      isRotated, res1[i].selector + " correctly rotated.");
-  }
-});
diff --git a/devtools/client/inspector/computed/computed.js b/devtools/client/inspector/computed/computed.js
index 95c81f0cf14d..c721518adff8 100644
--- a/devtools/client/inspector/computed/computed.js
+++ b/devtools/client/inspector/computed/computed.js
@@ -26,9 +26,14 @@ const {
 const StyleInspectorMenu = require("devtools/client/inspector/shared/style-inspector-menu");
 const TooltipsOverlay = require("devtools/client/inspector/shared/tooltips-overlay");
 const KeyShortcuts = require("devtools/client/shared/key-shortcuts");
-const BoxModelView = require("devtools/client/inspector/components/deprecated-box-model");
 const clipboardHelper = require("devtools/shared/platform/clipboard");
 
+const { createElement, createFactory } = require("devtools/client/shared/vendor/react");
+const ReactDOM = require("devtools/client/shared/vendor/react-dom");
+const { Provider } = require("devtools/client/shared/vendor/react-redux");
+
+const BoxModelApp = createFactory(require("devtools/client/inspector/boxmodel/components/BoxModelApp"));
+
 const STYLE_INSPECTOR_PROPERTIES = "devtools/shared/locales/styleinspector.properties";
 const {LocalizationHelper} = require("devtools/shared/l10n");
 const STYLE_INSPECTOR_L10N = new LocalizationHelper(STYLE_INSPECTOR_PROPERTIES);
@@ -154,6 +159,7 @@ UpdateProcess.prototype = {
 function CssComputedView(inspector, document, pageStyle) {
   this.inspector = inspector;
   this.highlighters = inspector.highlighters;
+  this.store = inspector.store;
   this.styleDocument = document;
   this.styleWindow = this.styleDocument.defaultView;
   this.pageStyle = pageStyle;
@@ -174,6 +180,7 @@ function CssComputedView(inspector, document, pageStyle) {
 
   let doc = this.styleDocument;
   this.element = doc.getElementById("propertyContainer");
+  this.boxModelWrapper = doc.getElementById("boxmodel-wrapper");
   this.searchField = doc.getElementById("computedview-searchbox");
   this.searchClearButton = doc.getElementById("computedview-searchinput-clear");
   this.includeBrowserStylesCheckbox =
@@ -209,6 +216,7 @@ function CssComputedView(inspector, document, pageStyle) {
   // The element that we're inspecting, and the document that it comes from.
   this._viewedElement = null;
 
+  this.createBoxModelView();
   this.createStyleViews();
 
   this._contextmenu = new StyleInspectorMenu(this, { isRuleView: false });
@@ -552,10 +560,10 @@ CssComputedView.prototype = {
     this._filterChangedTimeout = setTimeout(() => {
       if (this.searchField.value.length > 0) {
         this.searchField.setAttribute("filled", true);
-        this.inspector.emit("computed-view-filtered", true);
+        this.boxModelWrapper.hidden = true;
       } else {
         this.searchField.removeAttribute("filled");
-        this.inspector.emit("computed-view-filtered", false);
+        this.boxModelWrapper.hidden = false;
       }
 
       this.refreshPanel();
@@ -605,6 +613,29 @@ CssComputedView.prototype = {
     this.inspector.emit("computed-view-sourcelinks-updated");
   },
 
+  /**
+   * Render the box model view.
+   */
+  createBoxModelView: function () {
+    let {
+      onHideBoxModelHighlighter,
+      onShowBoxModelEditor,
+      onShowBoxModelHighlighter,
+    } = this.inspector.boxmodel.getComponentProps();
+
+    let provider = createElement(
+      Provider,
+      { store: this.store },
+      BoxModelApp({
+        showBoxModelProperties: false,
+        onHideBoxModelHighlighter,
+        onShowBoxModelEditor,
+        onShowBoxModelHighlighter,
+      })
+    );
+    ReactDOM.render(provider, this.boxModelWrapper);
+  },
+
   /**
    * The CSS as displayed by the UI.
    */
@@ -783,7 +814,7 @@ CssComputedView.prototype = {
 
     // Nodes used in templating
     this.element = null;
-    this.panel = null;
+    this.boxModelWrapper = null;
     this.searchField = null;
     this.searchClearButton = null;
     this.includeBrowserStylesCheckbox = null;
@@ -796,6 +827,7 @@ CssComputedView.prototype = {
 
     this.inspector = null;
     this.highlighters = null;
+    this.store = null;
     this.styleDocument = null;
     this.styleWindow = null;
 
@@ -1416,7 +1448,6 @@ function ComputedViewTool(inspector, window) {
 
   this.computedView = new CssComputedView(this.inspector, this.document,
     this.inspector.pageStyle);
-  this.boxModelView = new BoxModelView(this.inspector, this.document);
 
   this.onSelected = this.onSelected.bind(this);
   this.refresh = this.refresh.bind(this);
@@ -1525,9 +1556,8 @@ ComputedViewTool.prototype = {
     }
 
     this.computedView.destroy();
-    this.boxModelView.destroy();
 
-    this.computedView = this.boxModelView = this.document = this.inspector = null;
+    this.computedView = this.document = this.inspector = null;
   }
 };
 
diff --git a/devtools/client/inspector/computed/test/browser_computed_search-filter.js b/devtools/client/inspector/computed/test/browser_computed_search-filter.js
index d5b2634f4884..f8f25f23a639 100644
--- a/devtools/client/inspector/computed/test/browser_computed_search-filter.js
+++ b/devtools/client/inspector/computed/test/browser_computed_search-filter.js
@@ -34,7 +34,7 @@ function* testToggleDefaultStyles(inspector, computedView) {
 function* testAddTextInFilter(inspector, computedView) {
   info("setting filter text to \"color\"");
   let doc = computedView.styleDocument;
-  let boxModelWrapper = doc.querySelector("#old-boxmodel-wrapper");
+  let boxModelWrapper = doc.getElementById("boxmodel-wrapper");
   let searchField = computedView.searchField;
   let onRefreshed = inspector.once("computed-view-refreshed");
   let win = computedView.styleWindow;
diff --git a/devtools/client/inspector/computed/test/browser_computed_search-filter_clear.js b/devtools/client/inspector/computed/test/browser_computed_search-filter_clear.js
index 2b4a29618310..39dcefcb3838 100644
--- a/devtools/client/inspector/computed/test/browser_computed_search-filter_clear.js
+++ b/devtools/client/inspector/computed/test/browser_computed_search-filter_clear.js
@@ -50,7 +50,7 @@ function* testClearSearchFilter(inspector, computedView) {
 
   let win = computedView.styleWindow;
   let doc = computedView.styleDocument;
-  let boxModelWrapper = doc.querySelector("#old-boxmodel-wrapper");
+  let boxModelWrapper = doc.getElementById("boxmodel-wrapper");
   let propertyViews = computedView.propertyViews;
   let searchField = computedView.searchField;
   let searchClearButton = computedView.searchClearButton;
diff --git a/devtools/client/inspector/inspector.js b/devtools/client/inspector/inspector.js
index 1e9af044f029..2b6aecf95c80 100644
--- a/devtools/client/inspector/inspector.js
+++ b/devtools/client/inspector/inspector.js
@@ -23,7 +23,7 @@ const Menu = require("devtools/client/framework/menu");
 const MenuItem = require("devtools/client/framework/menu-item");
 
 const {HTMLBreadcrumbs} = require("devtools/client/inspector/breadcrumbs");
-const {ComputedViewTool} = require("devtools/client/inspector/computed/computed");
+const BoxModel = require("devtools/client/inspector/boxmodel/box-model");
 const {FontInspector} = require("devtools/client/inspector/fonts/fonts");
 const {InspectorSearch} = require("devtools/client/inspector/inspector-search");
 const {RuleViewTool} = require("devtools/client/inspector/rules/rules");
@@ -78,8 +78,6 @@ const PORTRAIT_MODE_WIDTH = 700;
  * - computed-view-sourcelinks-updated
  *      Fired when the stylesheet source links have been updated (when switching
  *      to source-mapped files)
- * - computed-view-filtered
- *      Fired when the computed rules view is filtered
  * - rule-view-refreshed
  *      Fired when the rule view updates to a new node
  * - rule-view-sourcelinks-updated
@@ -572,6 +570,10 @@ Inspector.prototype = {
       defaultTab == "computedview");
 
     this.ruleview = new RuleViewTool(this, this.panelWin);
+    this.boxmodel = new BoxModel(this, this.panelWin);
+
+    const {ComputedViewTool} =
+      this.browserRequire("devtools/client/inspector/computed/computed");
     this.computedview = new ComputedViewTool(this, this.panelWin);
 
     if (Services.prefs.getBoolPref("devtools.layoutview.enabled")) {
diff --git a/devtools/client/inspector/inspector.xhtml b/devtools/client/inspector/inspector.xhtml
index d3e13fb7b781..529627161088 100644
--- a/devtools/client/inspector/inspector.xhtml
+++ b/devtools/client/inspector/inspector.xhtml
@@ -14,7 +14,6 @@
   <link rel="stylesheet" href="chrome://devtools/skin/computed.css"/>
   <link rel="stylesheet" href="chrome://devtools/skin/fonts.css"/>
   <link rel="stylesheet" href="chrome://devtools/skin/boxmodel.css"/>
-  <link rel="stylesheet" href="chrome://devtools/skin/deprecated-boxmodel.css"/>
   <link rel="stylesheet" href="chrome://devtools/skin/layout.css"/>
   <link rel="stylesheet" href="chrome://devtools/skin/animationinspector.css"/>
   <link rel="stylesheet" href="resource://devtools/client/shared/components/sidebar-toggle.css"/>
@@ -132,60 +131,7 @@
 
         <div id="computedview-container">
           <div id="computedview-container-focusable" tabindex="-1">
-            <div id="old-boxmodel-wrapper" tabindex="0"
-              data-localization-bundle="devtools/client/locales/boxmodel.properties">
-              <div id="old-boxmodel-header">
-                <div id="old-boxmodel-expander" class="expander theme-twisty expandable" open=""></div>
-                <span data-localization="content=boxmodel.title"></span>
-              </div>
-
-              <div id="old-boxmodel-container">
-                <div id="old-boxmodel-main">
-                  <span class="old-boxmodel-legend" data-box="margin" data-localization="content=boxmodel.margin;title=boxmodel.margin"></span>
-                  <div id="old-boxmodel-margins" data-box="margin" data-localization="title=boxmodel.margin">
-                    <span class="old-boxmodel-legend" data-box="border" data-localization="content=boxmodel.border;title=boxmodel.border"></span>
-                    <div id="old-boxmodel-borders" data-box="border" data-localization="title=boxmodel.border">
-                      <span class="old-boxmodel-legend" data-box="padding" data-localization="content=boxmodel.padding;title=boxmodel.padding"></span>
-                      <div id="old-boxmodel-padding" data-box="padding" data-localization="title=boxmodel.padding">
-                        <div id="old-boxmodel-content" data-box="content" data-localization="title=boxmodel.content">
-                        </div>
-                      </div>
-                    </div>
-                  </div>
-
-                  <p class="old-boxmodel-margin old-boxmodel-top"><span data-box="margin" class="old-boxmodel-editable" title="margin-top"></span></p>
-                  <p class="old-boxmodel-margin old-boxmodel-right"><span data-box="margin" class="old-boxmodel-editable" title="margin-right"></span></p>
-                  <p class="old-boxmodel-margin old-boxmodel-bottom"><span data-box="margin" class="old-boxmodel-editable" title="margin-bottom"></span></p>
-                  <p class="old-boxmodel-margin old-boxmodel-left"><span data-box="margin" class="old-boxmodel-editable" title="margin-left"></span></p>
-
-                  <p class="old-boxmodel-border old-boxmodel-top"><span data-box="border" class="old-boxmodel-editable" title="border-top"></span></p>
-                  <p class="old-boxmodel-border old-boxmodel-right"><span data-box="border" class="old-boxmodel-editable" title="border-right"></span></p>
-                  <p class="old-boxmodel-border old-boxmodel-bottom"><span data-box="border" class="old-boxmodel-editable" title="border-bottom"></span></p>
-                  <p class="old-boxmodel-border old-boxmodel-left"><span data-box="border" class="old-boxmodel-editable" title="border-left"></span></p>
-
-                  <p class="old-boxmodel-padding old-boxmodel-top"><span data-box="padding" class="old-boxmodel-editable" title="padding-top"></span></p>
-                  <p class="old-boxmodel-padding old-boxmodel-right"><span data-box="padding" class="old-boxmodel-editable" title="padding-right"></span></p>
-                  <p class="old-boxmodel-padding old-boxmodel-bottom"><span data-box="padding" class="old-boxmodel-editable" title="padding-bottom"></span></p>
-                  <p class="old-boxmodel-padding old-boxmodel-left"><span data-box="padding" class="old-boxmodel-editable" title="padding-left"></span></p>
-
-                  <p class="old-boxmodel-size">
-                    <span data-box="content" data-localization="title=boxmodel.content"></span>
-                  </p>
-                </div>
-
-                <div id="old-boxmodel-info">
-                  <span id="old-boxmodel-element-size"></span>
-                  <section id="old-boxmodel-position-group">
-                    <button class="devtools-button" id="old-layout-geometry-editor"
-                            data-localization="title=boxmodel.geometryButton.tooltip"></button>
-                    <span id="old-boxmodel-element-position"></span>
-                  </section>
-                </div>
-
-                <div style="display: none">
-                  <p id="old-boxmodel-dummy"></p>
-                </div>
-              </div>
+            <div id="boxmodel-wrapper" tabindex="0">
             </div>
 
             <div id="propertyContainer" class="theme-separator" tabindex="0" dir="ltr">
diff --git a/devtools/client/inspector/layout/actions/index.js b/devtools/client/inspector/layout/actions/index.js
index d694e37400a2..bf11969f238b 100644
--- a/devtools/client/inspector/layout/actions/index.js
+++ b/devtools/client/inspector/layout/actions/index.js
@@ -17,9 +17,6 @@ createEnum([
   // Update the entire grids state with the new list of grids.
   "UPDATE_GRIDS",
 
-  // Update the layout state with the latest layout properties.
-  "UPDATE_LAYOUT",
-
   // Update the grid highlighter's show grid line numbers state.
   "UPDATE_SHOW_GRID_LINE_NUMBERS",
 
diff --git a/devtools/client/inspector/layout/actions/moz.build b/devtools/client/inspector/layout/actions/moz.build
index 5e157a4bd728..09b7039d19de 100644
--- a/devtools/client/inspector/layout/actions/moz.build
+++ b/devtools/client/inspector/layout/actions/moz.build
@@ -5,7 +5,6 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DevToolsModules(
-    'box-model.js',
     'grids.js',
     'highlighter-settings.js',
     'index.js',
diff --git a/devtools/client/inspector/layout/components/App.js b/devtools/client/inspector/layout/components/App.js
index d8dd19582d0c..cbcb2bebc271 100644
--- a/devtools/client/inspector/layout/components/App.js
+++ b/devtools/client/inspector/layout/components/App.js
@@ -11,9 +11,10 @@ const { connect } = require("devtools/client/shared/vendor/react-redux");
 const { LocalizationHelper } = require("devtools/shared/l10n");
 
 const Accordion = createFactory(require("./Accordion"));
-const BoxModel = createFactory(require("./BoxModel"));
 const Grid = createFactory(require("./Grid"));
 
+const BoxModel = createFactory(require("devtools/client/inspector/boxmodel/components/BoxModel"));
+
 const Types = require("../types");
 const { getStr } = require("../utils/l10n");
 
diff --git a/devtools/client/inspector/layout/components/moz.build b/devtools/client/inspector/layout/components/moz.build
index 7ad90ba4572b..551eaa5eda51 100644
--- a/devtools/client/inspector/layout/components/moz.build
+++ b/devtools/client/inspector/layout/components/moz.build
@@ -8,12 +8,6 @@ DevToolsModules(
     'Accordion.css',
     'Accordion.js',
     'App.js',
-    'BoxModel.js',
-    'BoxModelEditable.js',
-    'BoxModelInfo.js',
-    'BoxModelMain.js',
-    'BoxModelProperties.js',
-    'ComputedProperty.js',
     'Grid.js',
     'GridDisplaySettings.js',
     'GridItem.js',
diff --git a/devtools/client/inspector/layout/layout.js b/devtools/client/inspector/layout/layout.js
index d9c6ba201be7..2d6f1fe0cf60 100644
--- a/devtools/client/inspector/layout/layout.js
+++ b/devtools/client/inspector/layout/layout.js
@@ -6,18 +6,12 @@
 
 const Services = require("Services");
 const { Task } = require("devtools/shared/task");
-const { getCssProperties } = require("devtools/shared/fronts/css-properties");
-const { ReflowFront } = require("devtools/shared/fronts/reflow");
 
-const { InplaceEditor } = require("devtools/client/shared/inplace-editor");
 const { createFactory, createElement } = require("devtools/client/shared/vendor/react");
 const { Provider } = require("devtools/client/shared/vendor/react-redux");
 
 const SwatchColorPickerTooltip = require("devtools/client/shared/widgets/tooltip/SwatchColorPickerTooltip");
 
-const {
-  updateLayout,
-} = require("./actions/box-model");
 const {
   updateGridColor,
   updateGridHighlighted,
@@ -30,13 +24,10 @@ const {
 
 const App = createFactory(require("./components/App"));
 
-const EditingSession = require("./utils/editing-session");
-
 const { LocalizationHelper } = require("devtools/shared/l10n");
 const INSPECTOR_L10N =
   new LocalizationHelper("devtools/client/locales/inspector.properties");
 
-const NUMERIC = /^-?[\d\.]+$/;
 const SHOW_GRID_LINE_NUMBERS = "devtools.gridinspector.showGridLineNumbers";
 const SHOW_INFINITE_LINES_PREF = "devtools.gridinspector.showInfiniteLines";
 
@@ -59,11 +50,8 @@ function LayoutView(inspector, window) {
   this.store = inspector.store;
   this.walker = this.inspector.walker;
 
-  this.updateBoxModel = this.updateBoxModel.bind(this);
-
   this.onGridLayoutChange = this.onGridLayoutChange.bind(this);
   this.onHighlighterChange = this.onHighlighterChange.bind(this);
-  this.onNewSelection = this.onNewSelection.bind(this);
   this.onSidebarSelect = this.onSidebarSelect.bind(this);
 
   this.init();
@@ -80,13 +68,18 @@ LayoutView.prototype = {
       return;
     }
 
+    let {
+      onHideBoxModelHighlighter,
+      onShowBoxModelEditor,
+      onShowBoxModelHighlighter,
+    } = this.inspector.boxmodel.getComponentProps();
+
     this.layoutInspector = yield this.inspector.walker.getLayoutInspector();
 
     this.loadHighlighterSettings();
 
     this.highlighters.on("grid-highlighter-hidden", this.onHighlighterChange);
     this.highlighters.on("grid-highlighter-shown", this.onHighlighterChange);
-    this.inspector.selection.on("new-node-front", this.onNewSelection);
     this.inspector.sidebar.on("select", this.onSidebarSelect);
 
     // Create a shared SwatchColorPicker instance to be reused by all GridItem components.
@@ -112,13 +105,9 @@ LayoutView.prototype = {
        */
       showBoxModelProperties: true,
 
-      /**
-       * Hides the box-model highlighter on the currently selected element.
-       */
-      onHideBoxModelHighlighter: () => {
-        let toolbox = this.inspector.toolbox;
-        toolbox.highlighterUtils.unhighlight();
-      },
+      onHideBoxModelHighlighter,
+      onShowBoxModelEditor,
+      onShowBoxModelHighlighter,
 
       /**
        * Handler for a change in the grid overlay color picker for a grid container.
@@ -143,88 +132,6 @@ LayoutView.prototype = {
         }
       },
 
-      /**
-       * Shows the inplace editor when a box model editable value is clicked on the
-       * box model panel.
-       *
-       * @param  {DOMNode} element
-       *         The element that was clicked.
-       * @param  {Event} event
-       *         The event object.
-       * @param  {String} property
-       *         The name of the property.
-       */
-      onShowBoxModelEditor: (element, event, property) => {
-        let session = new EditingSession({
-          inspector: this.inspector,
-          doc: this.document,
-          elementRules: this.elementRules,
-        });
-        let initialValue = session.getProperty(property);
-
-        let editor = new InplaceEditor({
-          element: element,
-          initial: initialValue,
-          contentType: InplaceEditor.CONTENT_TYPES.CSS_VALUE,
-          property: {
-            name: property
-          },
-          start: self => {
-            self.elt.parentNode.classList.add("boxmodel-editing");
-          },
-          change: value => {
-            if (NUMERIC.test(value)) {
-              value += "px";
-            }
-
-            let properties = [
-              { name: property, value: value }
-            ];
-
-            if (property.substring(0, 7) == "border-") {
-              let bprop = property.substring(0, property.length - 5) + "style";
-              let style = session.getProperty(bprop);
-              if (!style || style == "none" || style == "hidden") {
-                properties.push({ name: bprop, value: "solid" });
-              }
-            }
-
-            session.setProperties(properties).catch(e => console.error(e));
-          },
-          done: (value, commit) => {
-            editor.elt.parentNode.classList.remove("boxmodel-editing");
-            if (!commit) {
-              session.revert().then(() => {
-                session.destroy();
-              }, e => console.error(e));
-              return;
-            }
-
-            let node = this.inspector.selection.nodeFront;
-            this.inspector.pageStyle.getLayout(node, {
-              autoMargins: true,
-            }).then(layout => {
-              this.store.dispatch(updateLayout(layout));
-            }, e => console.error(e));
-          },
-          contextMenu: this.inspector.onTextBoxContextMenu,
-          cssProperties: getCssProperties(this.inspector.toolbox)
-        }, event);
-      },
-
-      /**
-       * Shows the box-model highlighter on the currently selected element.
-       *
-       * @param  {Object} options
-       *         Options passed to the highlighter actor.
-       */
-      onShowBoxModelHighlighter: (options = {}) => {
-        let toolbox = this.inspector.toolbox;
-        let nodeFront = this.inspector.selection.nodeFront;
-
-        toolbox.highlighterUtils.highlightNodeFront(nodeFront, options);
-      },
-
       /**
        * Handler for a change in the input checkboxes in the GridList component.
        * Toggles on/off the grid highlighter for the provided grid container element.
@@ -309,16 +216,9 @@ LayoutView.prototype = {
   destroy() {
     this.highlighters.off("grid-highlighter-hidden", this.onHighlighterChange);
     this.highlighters.off("grid-highlighter-shown", this.onHighlighterChange);
-    this.inspector.selection.off("new-node-front", this.onNewSelection);
     this.inspector.sidebar.off("select", this.onSidebarSelect);
     this.layoutInspector.off("grid-layout-changed", this.onGridLayoutChange);
 
-    if (this.reflowFront) {
-      this.untrackReflows();
-      this.reflowFront.destroy();
-      this.reflowFront = null;
-    }
-
     this.document = null;
     this.inspector = null;
     this.layoutInspector = null;
@@ -372,16 +272,6 @@ LayoutView.prototype = {
            this.inspector.sidebar.getCurrentTabID() === "layoutview";
   },
 
-  /**
-   * Returns true if the layout panel is visible and the current node is valid to
-   * be displayed in the view.
-   */
-  isPanelVisibleAndNodeValid() {
-    return this.isPanelVisible() &&
-           this.inspector.selection.isConnected() &&
-           this.inspector.selection.isElementNode();
-  },
-
   /**
    * Load the grid highligher display settings into the store from the stored preferences.
    */
@@ -395,72 +285,6 @@ LayoutView.prototype = {
     dispatch(updateShowInfiniteLines(showInfinteLines));
   },
 
-  /**
-   * Starts listening to reflows in the current tab.
-   */
-  trackReflows() {
-    if (!this.reflowFront) {
-      let { target } = this.inspector;
-      if (target.form.reflowActor) {
-        this.reflowFront = ReflowFront(target.client,
-                                       target.form);
-      } else {
-        return;
-      }
-    }
-
-    this.reflowFront.on("reflows", this.updateBoxModel);
-    this.reflowFront.start();
-  },
-
-  /**
-   * Stops listening to reflows in the current tab.
-   */
-  untrackReflows() {
-    if (!this.reflowFront) {
-      return;
-    }
-
-    this.reflowFront.off("reflows", this.updateBoxModel);
-    this.reflowFront.stop();
-  },
-
-  /**
-   * Updates the box model panel by dispatching the new layout data.
-   */
-  updateBoxModel() {
-    let lastRequest = Task.spawn((function* () {
-      if (!(this.isPanelVisible() &&
-          this.inspector.selection.isConnected() &&
-          this.inspector.selection.isElementNode())) {
-        return null;
-      }
-
-      let node = this.inspector.selection.nodeFront;
-      let layout = yield this.inspector.pageStyle.getLayout(node, {
-        autoMargins: true,
-      });
-      let styleEntries = yield this.inspector.pageStyle.getApplied(node, {});
-      this.elementRules = styleEntries.map(e => e.rule);
-
-      // Update the redux store with the latest layout properties and update the box
-      // model view.
-      this.store.dispatch(updateLayout(layout));
-
-      // If a subsequent request has been made, wait for that one instead.
-      if (this._lastRequest != lastRequest) {
-        return this._lastRequest;
-      }
-
-      this._lastRequest = null;
-
-      this.inspector.emit("boxmodel-view-updated");
-      return null;
-    }).bind(this)).catch(console.error);
-
-    this._lastRequest = lastRequest;
-  },
-
   /**
    * Updates the grid panel by dispatching the new grid data. This is called when the
    * layout view becomes visible or the view needs to be updated with new grid data.
@@ -526,17 +350,6 @@ LayoutView.prototype = {
     this.store.dispatch(updateGridHighlighted(nodeFront, highlighted));
   },
 
-  /**
-   * Selection 'new-node-front' event handler.
-   */
-  onNewSelection: function () {
-    if (!this.isPanelVisibleAndNodeValid()) {
-      return;
-    }
-
-    this.updateBoxModel();
-  },
-
   /**
    * Handler for the inspector sidebar select event. Starts listening for
    * "grid-layout-changed" if the layout panel is visible. Otherwise, stop
@@ -546,17 +359,10 @@ LayoutView.prototype = {
   onSidebarSelect() {
     if (!this.isPanelVisible()) {
       this.layoutInspector.off("grid-layout-changed", this.onGridLayoutChange);
-      this.untrackReflows();
       return;
     }
 
-    if (this.inspector.selection.isConnected() &&
-        this.inspector.selection.isElementNode()) {
-      this.trackReflows();
-    }
-
     this.layoutInspector.on("grid-layout-changed", this.onGridLayoutChange);
-    this.updateBoxModel();
     this.updateGridPanel();
   },
 
diff --git a/devtools/client/inspector/layout/reducers/moz.build b/devtools/client/inspector/layout/reducers/moz.build
index 50e631af17b1..34867f4e837f 100644
--- a/devtools/client/inspector/layout/reducers/moz.build
+++ b/devtools/client/inspector/layout/reducers/moz.build
@@ -5,7 +5,6 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DevToolsModules(
-    'box-model.js',
     'grids.js',
     'highlighter-settings.js',
 )
diff --git a/devtools/client/inspector/layout/types.js b/devtools/client/inspector/layout/types.js
index b9c286200ca0..0c0cd3b77473 100644
--- a/devtools/client/inspector/layout/types.js
+++ b/devtools/client/inspector/layout/types.js
@@ -6,16 +6,6 @@
 
 const { PropTypes } = require("devtools/client/shared/vendor/react");
 
-/**
- * The box model data for the current selected node.
- */
-exports.boxModel = {
-
-  // The layout information of the current selected node
-  layout: PropTypes.object,
-
-};
-
 /**
  * A single grid container in the document.
  */
diff --git a/devtools/client/inspector/layout/utils/moz.build b/devtools/client/inspector/layout/utils/moz.build
index 537f779cc3cb..e3053b63fab6 100644
--- a/devtools/client/inspector/layout/utils/moz.build
+++ b/devtools/client/inspector/layout/utils/moz.build
@@ -5,6 +5,5 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DevToolsModules(
-    'editing-session.js',
     'l10n.js',
 )
diff --git a/devtools/client/inspector/moz.build b/devtools/client/inspector/moz.build
index 1c5f3e58dd4c..8f1679fd2b39 100644
--- a/devtools/client/inspector/moz.build
+++ b/devtools/client/inspector/moz.build
@@ -3,6 +3,7 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DIRS += [
+    'boxmodel',
     'components',
     'computed',
     'fonts',
diff --git a/devtools/client/inspector/reducers.js b/devtools/client/inspector/reducers.js
index 6c09e49c49e4..a6818664560e 100644
--- a/devtools/client/inspector/reducers.js
+++ b/devtools/client/inspector/reducers.js
@@ -7,6 +7,6 @@
 // This file exposes the Redux reducers of the box model, grid and grid highlighter
 // settings.
 
-exports.boxModel = require("devtools/client/inspector/layout/reducers/box-model");
+exports.boxModel = require("devtools/client/inspector/boxmodel/reducers/box-model");
 exports.grids = require("devtools/client/inspector/layout/reducers/grids");
 exports.highlighterSettings = require("devtools/client/inspector/layout/reducers/highlighter-settings");
diff --git a/devtools/client/inspector/test/browser_inspector_textbox-menu.js b/devtools/client/inspector/test/browser_inspector_textbox-menu.js
index a5e0e75622d8..b3e9ca68515c 100644
--- a/devtools/client/inspector/test/browser_inspector_textbox-menu.js
+++ b/devtools/client/inspector/test/browser_inspector_textbox-menu.js
@@ -66,7 +66,7 @@ add_task(function* () {
 
   info("Testing the box-model region");
   let margin = inspector.panelDoc.querySelector(
-    ".old-boxmodel-margin.old-boxmodel-top > span");
+    ".boxmodel-margin.boxmodel-top > span");
   EventUtils.synthesizeMouseAtCenter(margin, {}, inspector.panelWin);
   yield checkTextBox(inspector.panelDoc.activeElement, toolbox);
 });
diff --git a/devtools/client/inspector/test/shared-head.js b/devtools/client/inspector/test/shared-head.js
index a953d547e7f5..c42690a2813e 100644
--- a/devtools/client/inspector/test/shared-head.js
+++ b/devtools/client/inspector/test/shared-head.js
@@ -52,7 +52,15 @@ var openInspectorSidebarTab = Task.async(function* (id) {
   let {toolbox, inspector, testActor} = yield openInspector();
 
   info("Selecting the " + id + " sidebar");
-  inspector.sidebar.select(id);
+
+  if (id === "computedview" || id === "layoutview") {
+    // The layout and computed views should wait until the box-model widget is ready.
+    let onBoxModelViewReady = inspector.once("boxmodel-view-updated");
+    inspector.sidebar.select(id);
+    yield onBoxModelViewReady;
+  } else {
+    inspector.sidebar.select(id);
+  }
 
   return {
     toolbox,
diff --git a/devtools/client/jar.mn b/devtools/client/jar.mn
index 628a336e45c0..b68d20740c14 100644
--- a/devtools/client/jar.mn
+++ b/devtools/client/jar.mn
@@ -177,7 +177,6 @@ devtools.jar:
     skin/images/noise.png (themes/images/noise.png)
     skin/images/dropmarker.svg (themes/images/dropmarker.svg)
     skin/boxmodel.css (themes/boxmodel.css)
-    skin/deprecated-boxmodel.css (themes/deprecated-boxmodel.css)
     skin/images/geometry-editor.svg (themes/images/geometry-editor.svg)
     skin/images/pause.svg (themes/images/pause.svg)
     skin/images/play.svg (themes/images/play.svg)
diff --git a/devtools/client/shared/browser-loader.js b/devtools/client/shared/browser-loader.js
index ab7505beee9b..3aef74a99bf9 100644
--- a/devtools/client/shared/browser-loader.js
+++ b/devtools/client/shared/browser-loader.js
@@ -12,6 +12,8 @@ const Services = devtools.require("Services");
 const { AppConstants } = devtools.require("resource://gre/modules/AppConstants.jsm");
 
 const BROWSER_BASED_DIRS = [
+  "resource://devtools/client/inspector/boxmodel",
+  "resource://devtools/client/inspector/computed",
   "resource://devtools/client/inspector/layout",
   "resource://devtools/client/jsonview",
   "resource://devtools/client/shared/vendor",
diff --git a/devtools/client/themes/deprecated-boxmodel.css b/devtools/client/themes/deprecated-boxmodel.css
deleted file mode 100644
index e1f6d1432e20..000000000000
--- a/devtools/client/themes/deprecated-boxmodel.css
+++ /dev/null
@@ -1,259 +0,0 @@
-/* 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/ */
-
-/**
- * THIS STYLESHEET IS FOR THE DEPRECATED BOX MODEL MODULE (deprecated-box-model.js) AND
- * SHOULD NO LONGER BE MODIFIED.
- */
-
-#old-boxmodel-wrapper {
-  border-bottom-style: solid;
-  border-bottom-width: 1px;
-  border-color: var(--theme-splitter-color);
-  -moz-user-select: none;
-}
-
-#old-boxmodel-container {
-  /* The view will grow bigger as the window gets resized, until 400px */
-  max-width: 400px;
-  margin: 0px auto;
-  padding: 0;
-}
-
-/* Header */
-
-#old-boxmodel-header,
-#old-boxmodel-info {
-  display: flex;
-  align-items: center;
-  padding: 4px 17px;
-}
-
-#old-layout-geometry-editor {
-  visibility: hidden;
-}
-
-#old-layout-geometry-editor::before {
-  background: url(images/geometry-editor.svg) no-repeat center center / 16px 16px;
-}
-
-/* Main: contains the box-model regions */
-
-#old-boxmodel-main {
-  position: relative;
-  box-sizing: border-box;
-  /* The regions are semi-transparent, so the white background is partly
-     visible */
-  background-color: white;
-  color: var(--theme-selection-color);
-  /* Make sure there is some space between the window's edges and the regions */
-  margin: 0 14px 4px 14px;
-  width: calc(100% - 2 * 14px);
-}
-
-.old-boxmodel-margin,
-.old-boxmodel-size {
-  color: var(--theme-highlight-blue);
-}
-
-/* Regions are 3 nested elements with wide borders and outlines */
-
-#old-boxmodel-content {
-  height: 18px;
-}
-
-#old-boxmodel-margins,
-#old-boxmodel-borders,
-#old-boxmodel-padding {
-  border-color: hsla(210,100%,85%,0.2);
-  border-width: 18px;
-  border-style: solid;
-  outline: dotted 1px hsl(210,100%,85%);
-}
-
-#old-boxmodel-margins {
-  /* This opacity applies to all of the regions, since they are nested */
-  opacity: .8;
-}
-
-/* Regions colors */
-
-#old-boxmodel-margins {
-  border-color: #edff64;
-}
-
-#old-boxmodel-borders {
-  border-color: #444444;
-}
-
-#old-boxmodel-padding {
-  border-color: #6a5acd;
-}
-
-#old-boxmodel-content {
-  background-color: #87ceeb;
-}
-
-.theme-firebug #old-boxmodel-main,
-.theme-firebug #old-boxmodel-borders,
-.theme-firebug #old-boxmodel-content {
-  border-style: solid;
-}
-
-.theme-firebug #old-boxmodel-main,
-.theme-firebug #old-boxmodel-header {
-  font-family: var(--proportional-font-family);
-}
-
-.theme-firebug #old-boxmodel-main {
-  color: var(--theme-body-color);
-  font-size: var(--theme-toolbar-font-size);
-}
-
-.theme-firebug #old-boxmodel-header {
-  font-size: var(--theme-toolbar-font-size);
-}
-
-/* Editable region sizes are contained in absolutely positioned <p> */
-
-#old-boxmodel-main > p {
-  position: absolute;
-  pointer-events: none;
-  margin: 0;
-  text-align: center;
-}
-
-#old-boxmodel-main > p > span,
-#old-boxmodel-main > p > input {
-  vertical-align: middle;
-  pointer-events: auto;
-}
-
-/* Coordinates for the region sizes */
-
-.old-boxmodel-top,
-.old-boxmodel-bottom {
-  width: calc(100% - 2px);
-  text-align: center;
-}
-
-.old-boxmodel-padding.old-boxmodel-top {
-  top: 37px;
-}
-
-.old-boxmodel-padding.old-boxmodel-bottom {
-  bottom: 38px;
-}
-
-.old-boxmodel-border.old-boxmodel-top {
-  top: 19px;
-}
-
-.old-boxmodel-border.old-boxmodel-bottom {
-  bottom: 20px;
-}
-
-.old-boxmodel-margin.old-boxmodel-top {
-  top: 1px;
-}
-
-.old-boxmodel-margin.old-boxmodel-bottom {
-  bottom: 2px;
-}
-
-.old-boxmodel-size,
-.old-boxmodel-margin.old-boxmodel-left,
-.old-boxmodel-margin.old-boxmodel-right,
-.old-boxmodel-border.old-boxmodel-left,
-.old-boxmodel-border.old-boxmodel-right,
-.old-boxmodel-padding.old-boxmodel-left,
-.old-boxmodel-padding.old-boxmodel-right {
-  top: 22px;
-  line-height: 80px;
-}
-
-.old-boxmodel-size {
-  width: calc(100% - 2px);
-}
-
-.old-boxmodel-margin.old-boxmodel-right,
-.old-boxmodel-margin.old-boxmodel-left,
-.old-boxmodel-border.old-boxmodel-left,
-.old-boxmodel-border.old-boxmodel-right,
-.old-boxmodel-padding.old-boxmodel-right,
-.old-boxmodel-padding.old-boxmodel-left {
-  width: 21px;
-}
-
-.old-boxmodel-padding.old-boxmodel-left {
-  left: 35px;
-}
-
-.old-boxmodel-padding.old-boxmodel-right {
-  right: 35px;
-}
-
-.old-boxmodel-border.old-boxmodel-left {
-  left: 16px;
-}
-
-.old-boxmodel-border.old-boxmodel-right {
-  right: 17px;
-}
-
-.old-boxmodel-margin.old-boxmodel-right {
-  right: 0;
-}
-
-.old-boxmodel-margin.old-boxmodel-left {
-  left: 0;
-}
-
-.old-boxmodel-rotate.old-boxmodel-left:not(.old-boxmodel-editing) {
-  transform: rotate(-90deg);
-}
-
-.old-boxmodel-rotate.old-boxmodel-right:not(.old-boxmodel-editing) {
-  transform: rotate(90deg);
-}
-
-/* Legend: displayed inside regions */
-
-.old-boxmodel-legend {
-  position: absolute;
-  margin: 2px 6px;
-  z-index: 1;
-}
-
-.old-boxmodel-legend[data-box="margin"] {
-  color: var(--theme-highlight-blue);
-}
-
-/* Editable fields */
-
-.old-boxmodel-editable {
-  border: 1px dashed transparent;
-  -moz-user-select: none;
-}
-
-.old-boxmodel-editable:hover {
-  border-bottom-color: hsl(0, 0%, 50%);
-}
-
-/* Make sure the content size doesn't appear as editable like the other sizes */
-
-.old-boxmodel-size > span {
-  cursor: default;
-}
-
-/* Box Model Info: contains the position and size of the element */
-
-#old-boxmodel-element-size {
-  flex: 1;
-}
-
-#old-boxmodel-position-group {
-  display: flex;
-  align-items: center;
-}
diff --git a/devtools/server/tests/unit/test_frameactor_wasm-01.js b/devtools/server/tests/unit/test_frameactor_wasm-01.js
index 63376ae9efce..bc941b32283a 100644
--- a/devtools/server/tests/unit/test_frameactor_wasm-01.js
+++ b/devtools/server/tests/unit/test_frameactor_wasm-01.js
@@ -8,13 +8,9 @@
 var gDebuggee;
 var gClient;
 var gThreadClient;
-var gOldPref;
 
 function run_test()
 {
-  gOldPref = Services.prefs.getBoolPref("javascript.options.wasm");
-  Services.prefs.setBoolPref("javascript.options.wasm", true);
-
   if (typeof WebAssembly == "undefined") {
     return; // wasm is not enabled for this platform
   }
@@ -49,7 +45,6 @@ function test_pause_frame()
       do_check_eq(location.column > 0, true);
       do_check_eq(location.source.url.endsWith(" > wasm"), true);
 
-      Services.prefs.setBoolPref("javascript.options.wasm", gOldPref);
       finishClient(gClient);
     });
   });
@@ -58,7 +53,7 @@ function test_pause_frame()
     // WebAssembly bytecode was generated by running:
     // js -e 'print(wasmTextToBinary("(module(import \"a\" \"b\")(func(export \"c\")call 0))"))'
     var m = new WebAssembly.Module(new Uint8Array([
-      0,97,115,109,13,0,0,0,1,132,128,128,128,0,1,96,0,0,2,135,128,128,128,0,1,1,97,1,
+      0,97,115,109,1,0,0,0,1,132,128,128,128,0,1,96,0,0,2,135,128,128,128,0,1,1,97,1,
       98,0,0,3,130,128,128,128,0,1,0,6,129,128,128,128,0,0,7,133,128,128,128,0,1,1,99,
       0,1,10,138,128,128,128,0,1,132,128,128,128,0,0,16,0,11
     ]));
diff --git a/dom/base/CustomElementRegistry.cpp b/dom/base/CustomElementRegistry.cpp
index 2fcd326e11bb..362c43ff8ca9 100644
--- a/dom/base/CustomElementRegistry.cpp
+++ b/dom/base/CustomElementRegistry.cpp
@@ -172,7 +172,7 @@ NS_INTERFACE_MAP_END
 CustomElementRegistry::IsCustomElementEnabled(JSContext* aCx, JSObject* aObject)
 {
   return Preferences::GetBool("dom.webcomponents.customelements.enabled") ||
-         Preferences::GetBool("dom.webcomponents.enabled");
+         nsContentUtils::IsWebComponentsEnabled();
 }
 
 /* static */ already_AddRefed<CustomElementRegistry>
diff --git a/dom/base/nsContentUtils.cpp b/dom/base/nsContentUtils.cpp
index c09827e9497b..27d92cef1109 100644
--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -285,6 +285,7 @@ bool nsContentUtils::sIsPerformanceTimingEnabled = false;
 bool nsContentUtils::sIsResourceTimingEnabled = false;
 bool nsContentUtils::sIsUserTimingLoggingEnabled = false;
 bool nsContentUtils::sIsExperimentalAutocompleteEnabled = false;
+bool nsContentUtils::sIsWebComponentsEnabled = false;
 bool nsContentUtils::sEncodeDecodeURLHash = false;
 bool nsContentUtils::sGettersDecodeURLHash = false;
 bool nsContentUtils::sPrivacyResistFingerprinting = false;
@@ -512,10 +513,11 @@ nsContentUtils::Init()
   sSecurityManager->GetSystemPrincipal(&sSystemPrincipal);
   MOZ_ASSERT(sSystemPrincipal);
 
-  // We use the constructor here because we want infallible initialization; we
-  // apparently don't care whether sNullSubjectPrincipal has a sane URI or not.
-  RefPtr<nsNullPrincipal> nullPrincipal = new nsNullPrincipal();
-  nullPrincipal->Init();
+  RefPtr<nsNullPrincipal> nullPrincipal = nsNullPrincipal::Create();
+  if (!nullPrincipal) {
+    return NS_ERROR_FAILURE;
+  }
+
   nullPrincipal.forget(&sNullSubjectPrincipal);
 
   nsresult rv = CallGetService(NS_IOSERVICE_CONTRACTID, &sIOService);
@@ -582,6 +584,9 @@ nsContentUtils::Init()
   Preferences::AddBoolVarCache(&sIsExperimentalAutocompleteEnabled,
                                "dom.forms.autocomplete.experimental", false);
 
+  Preferences::AddBoolVarCache(&sIsWebComponentsEnabled,
+                               "dom.webcomponents.enabled", false);
+
   Preferences::AddBoolVarCache(&sEncodeDecodeURLHash,
                                "dom.url.encode_decode_hash", false);
 
diff --git a/dom/base/nsContentUtils.h b/dom/base/nsContentUtils.h
index af250c46c05b..e7889f9d1cbe 100644
--- a/dom/base/nsContentUtils.h
+++ b/dom/base/nsContentUtils.h
@@ -2806,6 +2806,9 @@ public:
                                     const mozilla::dom::Sequence<JSObject*>& aTransfer,
                                     JS::MutableHandle<JS::Value> aValue);
 
+  static bool
+  IsWebComponentsEnabled() { return sIsWebComponentsEnabled; }
+
 private:
   static bool InitializeEventTable();
 
@@ -2912,6 +2915,7 @@ private:
   static bool sIsUserTimingLoggingEnabled;
   static bool sIsFrameTimingPrefEnabled;
   static bool sIsExperimentalAutocompleteEnabled;
+  static bool sIsWebComponentsEnabled;
   static bool sEncodeDecodeURLHash;
   static bool sGettersDecodeURLHash;
   static bool sPrivacyResistFingerprinting;
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index f926212d9d05..708ca29b3103 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -104,6 +104,7 @@
 #include "nsIScriptSecurityManager.h"
 #include "nsIPermissionManager.h"
 #include "nsIPrincipal.h"
+#include "nsNullPrincipal.h"
 
 #include "nsIDOMWindow.h"
 #include "nsPIDOMWindow.h"
@@ -2736,7 +2737,7 @@ nsDocument::InitCSP(nsIChannel* aChannel)
   if (cspSandboxFlags & SANDBOXED_ORIGIN) {
     // If the new CSP sandbox flags do not have the allow-same-origin flag
     // reset the document principal to a null principal
-    principal = do_CreateInstance("@mozilla.org/nullprincipal;1");
+    principal = nsNullPrincipal::Create();
     SetPrincipal(principal);
   }
 
@@ -5941,7 +5942,7 @@ nsDocument::IsWebComponentsEnabled(JSContext* aCx, JSObject* aObject)
 {
   JS::Rooted<JSObject*> obj(aCx, aObject);
 
-  if (Preferences::GetBool("dom.webcomponents.enabled")) {
+  if (nsContentUtils::IsWebComponentsEnabled()) {
     return true;
   }
 
@@ -5957,7 +5958,7 @@ nsDocument::IsWebComponentsEnabled(JSContext* aCx, JSObject* aObject)
 bool
 nsDocument::IsWebComponentsEnabled(dom::NodeInfo* aNodeInfo)
 {
-  if (Preferences::GetBool("dom.webcomponents.enabled")) {
+  if (nsContentUtils::IsWebComponentsEnabled()) {
     return true;
   }
 
diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 5f867545f177..3a9887d6bde9 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -9406,21 +9406,16 @@ public:
         nsAutoString addonId;
         if (NS_SUCCEEDED(pc->GetAddonId(addonId)) && !addonId.IsEmpty()) {
           // We want to nuke all references to the add-on compartment.
-          js::NukeCrossCompartmentWrappers(cx, js::AllCompartments(),
-                                           js::SingleCompartment(cpt),
-                                           win->IsInnerWindow() ? js::DontNukeWindowReferences
-                                                                : js::NukeWindowReferences);
-
-          // Now mark the compartment as nuked and non-scriptable.
-          auto compartmentPrivate = xpc::CompartmentPrivate::Get(cpt);
-          compartmentPrivate->wasNuked = true;
-          compartmentPrivate->scriptability.Block();
+          xpc::NukeAllWrappersForCompartment(cx, cpt,
+                                             win->IsInnerWindow() ? js::DontNukeWindowReferences
+                                                                  : js::NukeWindowReferences);
         } else {
           // We only want to nuke wrappers for the chrome->content case
           js::NukeCrossCompartmentWrappers(cx, BrowserCompartmentMatcher(),
                                            js::SingleCompartment(cpt),
                                            win->IsInnerWindow() ? js::DontNukeWindowReferences
-                                                                : js::NukeWindowReferences);
+                                                                : js::NukeWindowReferences,
+                                           js::NukeIncomingReferences);
         }
       }
     }
diff --git a/dom/base/test/test_postMessages.html b/dom/base/test/test_postMessages.html
index 13a284270083..f4cd87432fb9 100644
--- a/dom/base/test/test_postMessages.html
+++ b/dom/base/test/test_postMessages.html
@@ -11,8 +11,7 @@
 <script type="application/javascript;version=1.7">
 
 function setup_tests() {
-  SpecialPowers.pushPrefEnv({"set": [["dom.input.dirpicker", true],
-                                     ["javascript.options.wasm", true]]}, next);
+  SpecialPowers.pushPrefEnv({"set": [["dom.input.dirpicker", true]]}, next);
 }
 
 function getType(a) {
diff --git a/dom/canvas/CanvasRenderingContext2D.cpp b/dom/canvas/CanvasRenderingContext2D.cpp
index f1f46e4767db..e2d00e4f0078 100644
--- a/dom/canvas/CanvasRenderingContext2D.cpp
+++ b/dom/canvas/CanvasRenderingContext2D.cpp
@@ -1906,11 +1906,7 @@ CanvasRenderingContext2D::GetHeight() const
 NS_IMETHODIMP
 CanvasRenderingContext2D::SetDimensions(int32_t aWidth, int32_t aHeight)
 {
-  bool retainBuffer = false;
-  if (aWidth == mWidth && aHeight == mHeight) {
-    retainBuffer = true;
-  }
-  ClearTarget(retainBuffer);
+  ClearTarget();
 
   // Zero sized surfaces can cause problems.
   mZero = false;
@@ -1929,23 +1925,10 @@ CanvasRenderingContext2D::SetDimensions(int32_t aWidth, int32_t aHeight)
 }
 
 void
-CanvasRenderingContext2D::ClearTarget(bool aRetainBuffer)
+CanvasRenderingContext2D::ClearTarget()
 {
-  RefPtr<PersistentBufferProvider> provider = mBufferProvider;
-  if (aRetainBuffer && provider) {
-    // We should reset the buffer data before reusing the buffer.
-    if (mTarget) {
-      mTarget->SetTransform(Matrix());
-    }
-    ClearRect(0, 0, mWidth, mHeight);
-  }
-
   Reset();
 
-  if (aRetainBuffer) {
-    mBufferProvider = provider;
-  }
-
   mResetLayer = true;
 
   SetInitialState();
diff --git a/dom/canvas/CanvasRenderingContext2D.h b/dom/canvas/CanvasRenderingContext2D.h
index 5fdb847dfc81..8995f69e0144 100644
--- a/dom/canvas/CanvasRenderingContext2D.h
+++ b/dom/canvas/CanvasRenderingContext2D.h
@@ -682,7 +682,7 @@ protected:
   /**
    * Disposes an old target and prepares to lazily create a new target.
    */
-  void ClearTarget(bool aRetainBuffer = false);
+  void ClearTarget();
 
   /*
    * Returns the target to the buffer provider. i.e. this will queue a frame for
diff --git a/dom/html/HTMLInputElement.cpp b/dom/html/HTMLInputElement.cpp
index 94cc0c249246..3f1175c76cc2 100644
--- a/dom/html/HTMLInputElement.cpp
+++ b/dom/html/HTMLInputElement.cpp
@@ -544,9 +544,8 @@ GetDOMFileOrDirectoryPath(const OwningFileOrDirectory& aData,
 bool
 HTMLInputElement::ValueAsDateEnabled(JSContext* cx, JSObject* obj)
 {
-  return Preferences::GetBool("dom.experimental_forms", false) ||
-    Preferences::GetBool("dom.forms.datepicker", false) ||
-    Preferences::GetBool("dom.forms.datetime", false);
+  return IsExperimentalFormsEnabled() || IsDatePickerEnabled() ||
+         IsInputDateTimeEnabled();
 }
 
 NS_IMETHODIMP
@@ -629,7 +628,7 @@ HTMLInputElement::nsFilePickerShownCallback::Done(int16_t aResult)
   RefPtr<DispatchChangeEventCallback> dispatchChangeEventCallback =
     new DispatchChangeEventCallback(mInput);
 
-  if (Preferences::GetBool("dom.webkitBlink.dirPicker.enabled", false) &&
+  if (IsWebkitDirPickerEnabled() &&
       mInput->HasAttr(kNameSpaceID_None, nsGkAtoms::webkitdirectory)) {
     ErrorResult error;
     GetFilesHelper* helper = mInput->GetOrCreateGetFilesHelper(true, error);
@@ -830,7 +829,7 @@ HTMLInputElement::IsPopupBlocked() const
 nsresult
 HTMLInputElement::InitDatePicker()
 {
-  if (!Preferences::GetBool("dom.forms.datepicker", false)) {
+  if (!IsDatePickerEnabled()) {
     return NS_OK;
   }
 
@@ -2568,10 +2567,8 @@ bool
 HTMLInputElement::IsExperimentalMobileType(uint8_t aType)
 {
   return (aType == NS_FORM_INPUT_DATE &&
-    !Preferences::GetBool("dom.forms.datetime", false) &&
-    !Preferences::GetBool("dom.forms.datepicker", false)) ||
-    (aType == NS_FORM_INPUT_TIME &&
-     !Preferences::GetBool("dom.forms.datetime", false));
+    !IsInputDateTimeEnabled() && !IsDatePickerEnabled()) ||
+    (aType == NS_FORM_INPUT_TIME && !IsInputDateTimeEnabled());
 }
 
 bool
@@ -3020,8 +3017,8 @@ HTMLInputElement::GetDisplayFileName(nsAString& aValue) const
   nsXPIDLString value;
 
   if (mFilesOrDirectories.IsEmpty()) {
-    if ((Preferences::GetBool("dom.input.dirpicker", false) && Allowdirs()) ||
-        (Preferences::GetBool("dom.webkitBlink.dirPicker.enabled", false) &&
+    if ((IsDirPickerEnabled() && Allowdirs()) ||
+        (IsWebkitDirPickerEnabled() &&
          HasAttr(kNameSpaceID_None, nsGkAtoms::webkitdirectory))) {
       nsContentUtils::GetLocalizedString(nsContentUtils::eFORMS_PROPERTIES,
                                          "NoDirSelected", value);
@@ -3050,7 +3047,7 @@ HTMLInputElement::SetFilesOrDirectories(const nsTArray<OwningFileOrDirectory>& a
 {
   ClearGetFilesHelpers();
 
-  if (Preferences::GetBool("dom.webkitBlink.filesystem.enabled", false)) {
+  if (IsWebkitFileSystemEnabled()) {
     HTMLInputElementBinding::ClearCachedWebkitEntriesValue(this);
     mEntries.Clear();
   }
@@ -3069,7 +3066,7 @@ HTMLInputElement::SetFiles(nsIDOMFileList* aFiles,
   mFilesOrDirectories.Clear();
   ClearGetFilesHelpers();
 
-  if (Preferences::GetBool("dom.webkitBlink.filesystem.enabled", false)) {
+  if (IsWebkitFileSystemEnabled()) {
     HTMLInputElementBinding::ClearCachedWebkitEntriesValue(this);
     mEntries.Clear();
   }
@@ -3092,14 +3089,14 @@ HTMLInputElement::MozSetDndFilesAndDirectories(const nsTArray<OwningFileOrDirect
 {
   SetFilesOrDirectories(aFilesOrDirectories, true);
 
-  if (Preferences::GetBool("dom.webkitBlink.filesystem.enabled", false)) {
+  if (IsWebkitFileSystemEnabled()) {
     UpdateEntries(aFilesOrDirectories);
   }
 
   RefPtr<DispatchChangeEventCallback> dispatchChangeEventCallback =
     new DispatchChangeEventCallback(this);
 
-  if (Preferences::GetBool("dom.webkitBlink.dirPicker.enabled", false) &&
+  if (IsWebkitDirPickerEnabled() &&
       HasAttr(kNameSpaceID_None, nsGkAtoms::webkitdirectory)) {
     ErrorResult rv;
     GetFilesHelper* helper = GetOrCreateGetFilesHelper(true /* recursionFlag */,
@@ -3179,8 +3176,8 @@ HTMLInputElement::GetFiles()
     return nullptr;
   }
 
-  if (Preferences::GetBool("dom.input.dirpicker", false) && Allowdirs() &&
-      (!Preferences::GetBool("dom.webkitBlink.dirPicker.enabled", false) ||
+  if (IsDirPickerEnabled() && Allowdirs() &&
+      (!IsWebkitDirPickerEnabled() ||
        !HasAttr(kNameSpaceID_None, nsGkAtoms::webkitdirectory))) {
     return nullptr;
   }
@@ -4392,8 +4389,8 @@ HTMLInputElement::MaybeInitPickers(EventChainPostVisitor& aVisitor)
       do_QueryInterface(aVisitor.mEvent->mOriginalTarget);
     if (target &&
         target->FindFirstNonChromeOnlyAccessContent() == this &&
-        ((Preferences::GetBool("dom.input.dirpicker", false) && Allowdirs()) ||
-         (Preferences::GetBool("dom.webkitBlink.dirPicker.enabled", false) &&
+        ((IsDirPickerEnabled() && Allowdirs()) ||
+         (IsWebkitDirPickerEnabled() &&
           HasAttr(kNameSpaceID_None, nsGkAtoms::webkitdirectory)))) {
       type = FILE_PICKER_DIRECTORY;
     }
@@ -5798,20 +5795,133 @@ HTMLInputElement::ParseTime(const nsAString& aValue, uint32_t* aResult)
   return true;
 }
 
-static bool
-IsDateTimeEnabled(int32_t aNewType)
+/* static */ bool
+HTMLInputElement::IsDateTimeTypeSupported(uint8_t aDateTimeInputType)
 {
-  return (aNewType == NS_FORM_INPUT_DATE &&
-          (Preferences::GetBool("dom.forms.datetime", false) ||
-           Preferences::GetBool("dom.experimental_forms", false) ||
-           Preferences::GetBool("dom.forms.datepicker", false))) ||
-         (aNewType == NS_FORM_INPUT_TIME &&
-          (Preferences::GetBool("dom.forms.datetime", false) ||
-           Preferences::GetBool("dom.experimental_forms", false))) ||
-         ((aNewType == NS_FORM_INPUT_MONTH ||
-           aNewType == NS_FORM_INPUT_WEEK ||
-           aNewType == NS_FORM_INPUT_DATETIME_LOCAL) &&
-          Preferences::GetBool("dom.forms.datetime", false));
+  return (aDateTimeInputType == NS_FORM_INPUT_DATE &&
+          (IsInputDateTimeEnabled() || IsExperimentalFormsEnabled() ||
+           IsDatePickerEnabled())) ||
+         (aDateTimeInputType == NS_FORM_INPUT_TIME &&
+          (IsInputDateTimeEnabled() || IsExperimentalFormsEnabled())) ||
+         ((aDateTimeInputType == NS_FORM_INPUT_MONTH ||
+           aDateTimeInputType == NS_FORM_INPUT_WEEK ||
+           aDateTimeInputType == NS_FORM_INPUT_DATETIME_LOCAL) &&
+          IsInputDateTimeEnabled());
+}
+
+/* static */ bool
+HTMLInputElement::IsWebkitDirPickerEnabled()
+{
+  static bool sWebkitDirPickerEnabled = false;
+  static bool sWebkitDirPickerPrefCached = false;
+  if (!sWebkitDirPickerPrefCached) {
+    sWebkitDirPickerPrefCached = true;
+    Preferences::AddBoolVarCache(&sWebkitDirPickerEnabled,
+                                 "dom.webkitBlink.dirPicker.enabled",
+                                 false);
+  }
+
+  return sWebkitDirPickerEnabled;
+}
+
+/* static */ bool
+HTMLInputElement::IsWebkitFileSystemEnabled()
+{
+  static bool sWebkitFileSystemEnabled = false;
+  static bool sWebkitFileSystemPrefCached = false;
+  if (!sWebkitFileSystemPrefCached) {
+    sWebkitFileSystemPrefCached = true;
+    Preferences::AddBoolVarCache(&sWebkitFileSystemEnabled,
+                                 "dom.webkitBlink.filesystem.enabled",
+                                 false);
+  }
+
+  return sWebkitFileSystemEnabled;
+}
+
+/* static */ bool
+HTMLInputElement::IsDirPickerEnabled()
+{
+  static bool sDirPickerEnabled = false;
+  static bool sDirPickerPrefCached = false;
+  if (!sDirPickerPrefCached) {
+    sDirPickerPrefCached = true;
+    Preferences::AddBoolVarCache(&sDirPickerEnabled, "dom.input.dirpicker",
+                                 false);
+  }
+
+  return sDirPickerEnabled;
+}
+
+/* static */ bool
+HTMLInputElement::IsDatePickerEnabled()
+{
+  static bool sDatePickerEnabled = false;
+  static bool sDatePickerPrefCached = false;
+  if (!sDatePickerPrefCached) {
+    sDatePickerPrefCached = true;
+    Preferences::AddBoolVarCache(&sDatePickerEnabled, "dom.forms.datepicker",
+                                 false);
+  }
+
+  return sDatePickerEnabled;
+}
+
+/* static */ bool
+HTMLInputElement::IsExperimentalFormsEnabled()
+{
+  static bool sExperimentalFormsEnabled = false;
+  static bool sExperimentalFormsPrefCached = false;
+  if (!sExperimentalFormsPrefCached) {
+    sExperimentalFormsPrefCached = true;
+    Preferences::AddBoolVarCache(&sExperimentalFormsEnabled,
+                                 "dom.experimental_forms",
+                                 false);
+  }
+
+  return sExperimentalFormsEnabled;
+}
+
+/* static */ bool
+HTMLInputElement::IsInputDateTimeEnabled()
+{
+  static bool sDateTimeEnabled = false;
+  static bool sDateTimePrefCached = false;
+  if (!sDateTimePrefCached) {
+    sDateTimePrefCached = true;
+    Preferences::AddBoolVarCache(&sDateTimeEnabled, "dom.forms.datetime",
+                                 false);
+  }
+
+  return sDateTimeEnabled;
+}
+
+/* static */ bool
+HTMLInputElement::IsInputNumberEnabled()
+{
+  static bool sInputNumberEnabled = false;
+  static bool sInputNumberPrefCached = false;
+  if (!sInputNumberPrefCached) {
+    sInputNumberPrefCached = true;
+    Preferences::AddBoolVarCache(&sInputNumberEnabled, "dom.forms.number",
+                                 false);
+  }
+
+  return sInputNumberEnabled;
+}
+
+/* static */ bool
+HTMLInputElement::IsInputColorEnabled()
+{
+  static bool sInputColorEnabled = false;
+  static bool sInputColorPrefCached = false;
+  if (!sInputColorPrefCached) {
+    sInputColorPrefCached = true;
+    Preferences::AddBoolVarCache(&sInputColorEnabled, "dom.forms.color",
+                                 false);
+  }
+
+  return sInputColorEnabled;
 }
 
 bool
@@ -5829,12 +5939,11 @@ HTMLInputElement::ParseAttribute(int32_t aNamespaceID,
       if (success) {
         newType = aResult.GetEnumValue();
         if ((IsExperimentalMobileType(newType) &&
-             !Preferences::GetBool("dom.experimental_forms", false)) ||
-            (newType == NS_FORM_INPUT_NUMBER &&
-             !Preferences::GetBool("dom.forms.number", false)) ||
-            (newType == NS_FORM_INPUT_COLOR &&
-             !Preferences::GetBool("dom.forms.color", false)) ||
-            (IsDateTimeInputType(newType) && !IsDateTimeEnabled(newType))) {
+             !IsExperimentalFormsEnabled()) ||
+            (newType == NS_FORM_INPUT_NUMBER && !IsInputNumberEnabled()) ||
+            (newType == NS_FORM_INPUT_COLOR && !IsInputColorEnabled()) ||
+            (IsDateTimeInputType(newType) &&
+             !IsDateTimeTypeSupported(newType))) {
           newType = kInputDefaultType->value;
           aResult.SetTo(newType, &aValue);
         }
diff --git a/dom/html/HTMLInputElement.h b/dom/html/HTMLInputElement.h
index 69db31fd9612..ddf640d9719e 100644
--- a/dom/html/HTMLInputElement.h
+++ b/dom/html/HTMLInputElement.h
@@ -1650,6 +1650,69 @@ private:
            aType == NS_FORM_INPUT_TIME;
   }
 
+  /**
+   * Checks if aDateTimeInputType should be supported based on "dom.forms.datetime",
+   * "dom.forms.datepicker" and "dom.experimental_forms".
+   */
+  static bool
+  IsDateTimeTypeSupported(uint8_t aDateTimeInputType);
+
+  /**
+   * Checks preference "dom.webkitBlink.dirPicker.enabled" to determine if
+   * webkitdirectory should be supported.
+   */
+  static bool
+  IsWebkitDirPickerEnabled();
+
+  /**
+   * Checks preference "dom.webkitBlink.filesystem.enabled" to determine if
+   * webkitEntries should be supported.
+   */
+  static bool
+  IsWebkitFileSystemEnabled();
+
+  /**
+   * Checks preference "dom.input.dirpicker" to determine if file and directory
+   * entries API should be supported.
+   */
+  static bool
+  IsDirPickerEnabled();
+
+  /**
+   * Checks preference "dom.forms.datepicker" to determine if date picker should
+   * be supported.
+   */
+  static bool
+  IsDatePickerEnabled();
+
+  /**
+   * Checks preference "dom.experimental_forms" to determine if experimental
+   * implementation of input element should be enabled.
+   */
+  static bool
+  IsExperimentalFormsEnabled();
+
+  /**
+   * Checks preference "dom.forms.datetime" to determine if input date/time
+   * related types should be supported.
+   */
+  static bool
+  IsInputDateTimeEnabled();
+
+  /**
+   * Checks preference "dom.forms.number" to determine if input type=number
+   * should be supported.
+   */
+  static bool
+  IsInputNumberEnabled();
+
+  /**
+   * Checks preference "dom.forms.color" to determine if date/time related
+   * types should be supported.
+   */
+  static bool
+  IsInputColorEnabled();
+
   struct nsFilePickerFilter {
     nsFilePickerFilter()
       : mFilterMask(0) {}
diff --git a/dom/indexedDB/test/helpers.js b/dom/indexedDB/test/helpers.js
index 39c0818205d7..2a69ff615370 100644
--- a/dom/indexedDB/test/helpers.js
+++ b/dom/indexedDB/test/helpers.js
@@ -75,8 +75,7 @@ function* testHarnessSteps() {
       "set": [
         ["dom.indexedDB.testing", true],
         ["dom.indexedDB.experimental", true],
-        ["dom.archivereader.enabled", true],
-        ["javascript.options.wasm", true]
+        ["dom.archivereader.enabled", true]
       ]
     },
     nextTestHarnessStep
diff --git a/dom/indexedDB/test/unit/wasm_recompile_profile.zip b/dom/indexedDB/test/unit/wasm_recompile_profile.zip
index 50ca3ef898de..8f9d67868e5d 100644
Binary files a/dom/indexedDB/test/unit/wasm_recompile_profile.zip and b/dom/indexedDB/test/unit/wasm_recompile_profile.zip differ
diff --git a/dom/indexedDB/test/unit/xpcshell-head-parent-process.js b/dom/indexedDB/test/unit/xpcshell-head-parent-process.js
index 03543a5d7e14..d56e8269cf8a 100644
--- a/dom/indexedDB/test/unit/xpcshell-head-parent-process.js
+++ b/dom/indexedDB/test/unit/xpcshell-head-parent-process.js
@@ -50,7 +50,6 @@ if (!this.runTest) {
 
       enableTesting();
       enableExperimental();
-      enableWasm();
     }
 
     Cu.importGlobalProperties(["indexedDB", "Blob", "File", "FileReader"]);
@@ -63,7 +62,6 @@ if (!this.runTest) {
 function finishTest()
 {
   if (SpecialPowers.isMainProcess()) {
-    resetWasm();
     resetExperimental();
     resetTesting();
 
@@ -214,16 +212,6 @@ function resetTesting()
   SpecialPowers.clearUserPref("dom.indexedDB.testing");
 }
 
-function enableWasm()
-{
-  SpecialPowers.setBoolPref("javascript.options.wasm", true);
-}
-
-function resetWasm()
-{
-  SpecialPowers.clearUserPref("javascript.options.wasm");
-}
-
 function gc()
 {
   Cu.forceGC();
diff --git a/dom/ipc/ContentPrefs.cpp b/dom/ipc/ContentPrefs.cpp
index 232570acd20a..6106e526af62 100644
--- a/dom/ipc/ContentPrefs.cpp
+++ b/dom/ipc/ContentPrefs.cpp
@@ -6,6 +6,10 @@
 
 #include "ContentPrefs.h"
 
+/************************************************************
+ *    DO NOT ADD PREFS TO THIS LIST WITHOUT DOM PEER REVIEW *
+ ************************************************************/
+
 const char* mozilla::dom::ContentPrefs::gInitPrefs[] = {
   "accessibility.monoaudio.enable",
   "accessibility.mouse_focuses_formcontrol",
@@ -52,6 +56,7 @@ const char* mozilla::dom::ContentPrefs::gInitPrefs[] = {
   "dom.vibrator.enabled",
   "dom.vibrator.max_vibrate_list_len",
   "dom.vibrator.max_vibrate_ms",
+  "dom.webcomponents.enabled",
   "focusmanager.testmode",
   "font.size.inflation.disabledInMasterProcess",
   "font.size.inflation.emPerLine",
diff --git a/dom/media/webaudio/test/test_audioContextSuspendResumeClose.html b/dom/media/webaudio/test/test_audioContextSuspendResumeClose.html
index e592cf0b1f6a..09ce1fd5aed3 100644
--- a/dom/media/webaudio/test/test_audioContextSuspendResumeClose.html
+++ b/dom/media/webaudio/test/test_audioContextSuspendResumeClose.html
@@ -48,10 +48,12 @@ function tryToCreateNodeOnClosedContext(ctx) {
 }
 
 function loadFile(url, callback) {
+  todo(false, "loadFile: " + url);
   var xhr = new XMLHttpRequest();
   xhr.open("GET", url, true);
   xhr.responseType = "arraybuffer";
   xhr.onload = function() {
+    todo(false, "loadFile: " + url + " calling callback...");
     callback(xhr.response);
   };
   xhr.send();
diff --git a/dom/network/UDPSocketParent.cpp b/dom/network/UDPSocketParent.cpp
index d3a7d7f2d221..3f4703ebe674 100644
--- a/dom/network/UDPSocketParent.cpp
+++ b/dom/network/UDPSocketParent.cpp
@@ -244,7 +244,7 @@ UDPSocketParent::RecvConnect(const UDPAddressInfo& aAddressInfo)
   nsCOMPtr<nsIEventTarget> thread(NS_GetCurrentThread());
   Unused <<
     NS_WARN_IF(NS_FAILED(GetSTSThread()->Dispatch(WrapRunnable(
-                                                    this,
+                                                    RefPtr<UDPSocketParent>(this),
                                                     &UDPSocketParent::DoConnect,
                                                     mSocket,
                                                     thread,
@@ -266,7 +266,7 @@ UDPSocketParent::SendConnectResponse(nsIEventTarget *aThread,
 {
   Unused <<
     NS_WARN_IF(NS_FAILED(aThread->Dispatch(WrapRunnable(
-                                             this,
+                                             RefPtr<UDPSocketParent>(this),
                                              &UDPSocketParent::DoSendConnectResponse,
                                              aAddressInfo),
                                            NS_DISPATCH_NORMAL)));
@@ -586,7 +586,7 @@ UDPSocketParent::SendInternalError(nsIEventTarget *aThread,
   UDPSOCKET_LOG(("SendInternalError: %u", aLineNo));
   Unused <<
     NS_WARN_IF(NS_FAILED(aThread->Dispatch(WrapRunnable(
-                                             this,
+                                             RefPtr<UDPSocketParent>(this),
                                              &UDPSocketParent::FireInternalError,
                                              aLineNo),
                                            NS_DISPATCH_NORMAL)));
diff --git a/dom/promise/tests/test_webassembly_compile.html b/dom/promise/tests/test_webassembly_compile.html
index 0243df49caab..5ee06cd02aeb 100644
--- a/dom/promise/tests/test_webassembly_compile.html
+++ b/dom/promise/tests/test_webassembly_compile.html
@@ -167,7 +167,7 @@ function runTest() {
 }
 
 SimpleTest.waitForExplicitFinish();
-SpecialPowers.pushPrefEnv({"set": [["javascript.options.wasm", true]]}, runTest);
+runTest();
 </script>
 </body>
 </html>
diff --git a/dom/tests/mochitest/general/test_interfaces.js b/dom/tests/mochitest/general/test_interfaces.js
index 80176a0fbe4f..9422ed2080f5 100644
--- a/dom/tests/mochitest/general/test_interfaces.js
+++ b/dom/tests/mochitest/general/test_interfaces.js
@@ -74,6 +74,7 @@ var ecmaGlobals =
     "URIError",
     "WeakMap",
     "WeakSet",
+    {name: "WebAssembly", disabled: !SpecialPowers.Cu.getJSTestingFunctions().wasmIsSupported()}
   ];
 // IMPORTANT: Do not change the list above without review from
 //            a JavaScript Engine peer!
diff --git a/dom/workers/ScriptLoader.cpp b/dom/workers/ScriptLoader.cpp
index 6d6cd257ba0d..f2f92a7c175f 100644
--- a/dom/workers/ScriptLoader.cpp
+++ b/dom/workers/ScriptLoader.cpp
@@ -476,6 +476,7 @@ private:
   UniquePtr<PrincipalInfo> mPrincipalInfo;
   nsCString mCSPHeaderValue;
   nsCString mCSPReportOnlyHeaderValue;
+  nsCString mReferrerPolicyHeaderValue;
 };
 
 NS_IMPL_ISUPPORTS(CacheScriptLoader, nsIStreamLoaderObserver)
@@ -622,6 +623,10 @@ private:
     MOZ_ASSERT(!loadInfo.mLoadingFinished);
     loadInfo.mLoadingFinished = true;
 
+    if (IsMainWorkerScript() && NS_SUCCEEDED(aRv)) {
+      MOZ_DIAGNOSTIC_ASSERT(mWorkerPrivate->PrincipalURIMatchesScriptURL());
+    }
+
     MaybeExecuteFinishedScripts(aIndex);
   }
 
@@ -1137,8 +1142,18 @@ private:
       // Store the channel info if needed.
       mWorkerPrivate->InitChannelInfo(channel);
 
+      // Our final channel principal should match the original principal
+      // in terms of the origin.
       MOZ_DIAGNOSTIC_ASSERT(mWorkerPrivate->FinalChannelPrincipalIsValid(channel));
 
+      // However, we must still override the principal since the nsIPrincipal
+      // URL may be different due to same-origin redirects.  Unfortunately this
+      // URL must exactly match the final worker script URL in order to
+      // properly set the referrer header on fetch/xhr requests.  If bug 1340694
+      // is ever fixed this can be removed.
+      rv = mWorkerPrivate->SetPrincipalFromChannel(channel);
+      NS_ENSURE_SUCCESS(rv, rv);
+
       // We did inherit CSP in bug 1223647. If we do not already have a CSP, we
       // should get it from the HTTP headers on the worker script.
       if (!mWorkerPrivate->GetCSP() && CSPService::sCSPEnabled) {
@@ -1146,6 +1161,9 @@ private:
                                                     tCspROHeaderValue);
         NS_ENSURE_SUCCESS(rv, rv);
       }
+
+      mWorkerPrivate->SetReferrerPolicyFromHeaderValue(tRPHeaderCValue);
+
       WorkerPrivate* parent = mWorkerPrivate->GetParent();
       if (parent) {
         // XHR Params Allowed
@@ -1153,16 +1171,6 @@ private:
       }
     }
 
-    NS_ConvertUTF8toUTF16 tRPHeaderValue(tRPHeaderCValue);
-    // If there's a Referrer-Policy header, apply it.
-    if (!tRPHeaderValue.IsEmpty()) {
-      net::ReferrerPolicy policy =
-        nsContentUtils::GetReferrerPolicyFromHeader(tRPHeaderValue);
-      if (policy != net::RP_Unset) {
-        mWorkerPrivate->SetReferrerPolicy(policy);
-      }
-    }
-
     return NS_OK;
   }
 
@@ -1172,7 +1180,8 @@ private:
                         const mozilla::dom::ChannelInfo& aChannelInfo,
                         UniquePtr<PrincipalInfo> aPrincipalInfo,
                         const nsACString& aCSPHeaderValue,
-                        const nsACString& aCSPReportOnlyHeaderValue)
+                        const nsACString& aCSPReportOnlyHeaderValue,
+                        const nsACString& aReferrerPolicyHeaderValue)
   {
     AssertIsOnMainThread();
     MOZ_ASSERT(aIndex < mLoadInfos.Length());
@@ -1230,13 +1239,16 @@ private:
       // Override the principal on the WorkerPrivate.  This is only necessary
       // in order to get a principal with exactly the correct URL.  The fetch
       // referrer logic depends on the WorkerPrivate principal having a URL
-      // that matches the worker script URL.
+      // that matches the worker script URL.  If bug 1340694 is ever fixed
+      // this can be removed.
       rv = mWorkerPrivate->SetPrincipalOnMainThread(responsePrincipal, loadGroup);
       MOZ_DIAGNOSTIC_ASSERT(NS_SUCCEEDED(rv));
 
       rv = mWorkerPrivate->SetCSPFromHeaderValues(aCSPHeaderValue,
                                                   aCSPReportOnlyHeaderValue);
       MOZ_DIAGNOSTIC_ASSERT(NS_SUCCEEDED(rv));
+
+      mWorkerPrivate->SetReferrerPolicyFromHeaderValue(aReferrerPolicyHeaderValue);
     }
 
     if (NS_SUCCEEDED(rv)) {
@@ -1652,6 +1664,8 @@ CacheScriptLoader::ResolvedCallback(JSContext* aCx,
                mCSPHeaderValue, ignored);
   headers->Get(NS_LITERAL_CSTRING("content-security-policy-report-only"),
                mCSPReportOnlyHeaderValue, ignored);
+  headers->Get(NS_LITERAL_CSTRING("referrer-policy"),
+               mReferrerPolicyHeaderValue, ignored);
 
   nsCOMPtr<nsIInputStream> inputStream;
   response->GetBody(getter_AddRefs(inputStream));
@@ -1665,7 +1679,8 @@ CacheScriptLoader::ResolvedCallback(JSContext* aCx,
     mLoadInfo.mCacheStatus = ScriptLoadInfo::Cached;
     mRunnable->DataReceivedFromCache(mIndex, (uint8_t*)"", 0, mChannelInfo,
                                      Move(mPrincipalInfo), mCSPHeaderValue,
-                                     mCSPReportOnlyHeaderValue);
+                                     mCSPReportOnlyHeaderValue,
+                                     mReferrerPolicyHeaderValue);
     return;
   }
 
@@ -1726,7 +1741,8 @@ CacheScriptLoader::OnStreamComplete(nsIStreamLoader* aLoader, nsISupports* aCont
   MOZ_ASSERT(mPrincipalInfo);
   mRunnable->DataReceivedFromCache(mIndex, aString, aStringLen, mChannelInfo,
                                    Move(mPrincipalInfo), mCSPHeaderValue,
-                                   mCSPReportOnlyHeaderValue);
+                                   mCSPReportOnlyHeaderValue,
+                                   mReferrerPolicyHeaderValue);
   return NS_OK;
 }
 
diff --git a/dom/workers/WorkerPrivate.cpp b/dom/workers/WorkerPrivate.cpp
index f79197835952..37ed1641d83f 100644
--- a/dom/workers/WorkerPrivate.cpp
+++ b/dom/workers/WorkerPrivate.cpp
@@ -1985,6 +1985,57 @@ WorkerLoadInfo::PrincipalIsValid() const
          mPrincipalInfo->type() != PrincipalInfo::T__None &&
          mPrincipalInfo->type() <= PrincipalInfo::T__Last;
 }
+
+bool
+WorkerLoadInfo::PrincipalURIMatchesScriptURL()
+{
+  AssertIsOnMainThread();
+
+  nsAutoCString scheme;
+  nsresult rv = mBaseURI->GetScheme(scheme);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  // A system principal must either be a blob URL or a resource JSM.
+  if (mPrincipal->GetIsSystemPrincipal()) {
+    if (scheme == NS_LITERAL_CSTRING("blob")) {
+      return true;
+    }
+
+    bool isResource = false;
+    nsresult rv = NS_URIChainHasFlags(mBaseURI,
+                                      nsIProtocolHandler::URI_IS_UI_RESOURCE,
+                                      &isResource);
+    NS_ENSURE_SUCCESS(rv, false);
+
+    return isResource;
+  }
+
+  // A null principal can occur for a data URL worker script or a blob URL
+  // worker script from a sandboxed iframe.
+  if (mPrincipal->GetIsNullPrincipal()) {
+    return scheme == NS_LITERAL_CSTRING("data") ||
+           scheme == NS_LITERAL_CSTRING("blob");
+  }
+
+  // The principal for a blob: URL worker script does not have a matching URL.
+  // This is likely a bug in our referer setting logic, but exempt it for now.
+  // This is another reason we should fix bug 1340694 so that referer does not
+  // depend on the principal URI.
+  if (scheme == NS_LITERAL_CSTRING("blob")) {
+    return true;
+  }
+
+  nsCOMPtr<nsIURI> principalURI;
+  rv = mPrincipal->GetURI(getter_AddRefs(principalURI));
+  NS_ENSURE_SUCCESS(rv, false);
+  NS_ENSURE_TRUE(principalURI, false);
+
+  bool equal = false;
+  rv = principalURI->Equals(mBaseURI, &equal);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  return equal;
+}
 #endif // defined(DEBUG) || !defined(RELEASE_OR_BETA)
 
 bool
@@ -2640,6 +2691,26 @@ WorkerPrivateParent<Derived>::SetCSPFromHeaderValues(const nsACString& aCSPHeade
   return NS_OK;
 }
 
+template <class Derived>
+void
+WorkerPrivateParent<Derived>::SetReferrerPolicyFromHeaderValue(
+                                  const nsACString& aReferrerPolicyHeaderValue)
+{
+  NS_ConvertUTF8toUTF16 headerValue(aReferrerPolicyHeaderValue);
+
+  if (headerValue.IsEmpty()) {
+    return;
+  }
+
+  net::ReferrerPolicy policy =
+    nsContentUtils::GetReferrerPolicyFromHeader(headerValue);
+  if (policy == net::RP_Unset) {
+    return;
+  }
+
+  SetReferrerPolicy(policy);
+}
+
 
 // Can't use NS_IMPL_CYCLE_COLLECTION_CLASS(WorkerPrivateParent) because of the
 // templates.
@@ -3869,6 +3940,13 @@ WorkerPrivateParent<Derived>::FinalChannelPrincipalIsValid(nsIChannel* aChannel)
 {
   return mLoadInfo.FinalChannelPrincipalIsValid(aChannel);
 }
+
+template <class Derived>
+bool
+WorkerPrivateParent<Derived>::PrincipalURIMatchesScriptURL()
+{
+  return mLoadInfo.PrincipalURIMatchesScriptURL();
+}
 #endif
 
 template <class Derived>
diff --git a/dom/workers/WorkerPrivate.h b/dom/workers/WorkerPrivate.h
index 545f2c63a1d2..5e243ec1057c 100644
--- a/dom/workers/WorkerPrivate.h
+++ b/dom/workers/WorkerPrivate.h
@@ -655,6 +655,9 @@ public:
 #if defined(DEBUG) || !defined(RELEASE_OR_BETA)
   bool
   FinalChannelPrincipalIsValid(nsIChannel* aChannel);
+
+  bool
+  PrincipalURIMatchesScriptURL();
 #endif
 
   bool
@@ -703,6 +706,9 @@ public:
   SetCSPFromHeaderValues(const nsACString& aCSPHeaderValue,
                          const nsACString& aCSPReportOnlyHeaderValue);
 
+  void
+  SetReferrerPolicyFromHeaderValue(const nsACString& aReferrerPolicyHeaderValue);
+
   net::ReferrerPolicy
   GetReferrerPolicy() const
   {
diff --git a/dom/workers/Workers.h b/dom/workers/Workers.h
index 66e5b9ecceab..f7b94c5394ba 100644
--- a/dom/workers/Workers.h
+++ b/dom/workers/Workers.h
@@ -296,6 +296,9 @@ struct WorkerLoadInfo
 
   bool
   PrincipalIsValid() const;
+
+  bool
+  PrincipalURIMatchesScriptURL();
 #endif
 
   bool
diff --git a/dom/workers/test/serviceworkers/test_serviceworker_interfaces.js b/dom/workers/test/serviceworkers/test_serviceworker_interfaces.js
index af6d37a1069d..4f663e991f5c 100644
--- a/dom/workers/test/serviceworkers/test_serviceworker_interfaces.js
+++ b/dom/workers/test/serviceworkers/test_serviceworker_interfaces.js
@@ -69,6 +69,7 @@ var ecmaGlobals =
     "URIError",
     "WeakMap",
     "WeakSet",
+    {name: "WebAssembly", optional: true}
   ];
 // IMPORTANT: Do not change the list above without review from
 //            a JavaScript Engine peer!
@@ -252,6 +253,8 @@ function createInterfaceMap(version, userAgent) {
             (entry.android === !isAndroid && !entry.nonReleaseAndroid && !entry.nightlyAndroid) ||
             (entry.release === !isRelease)) {
           interfaceMap[entry.name] = false;
+        } else if (entry.optional) {
+          interfaceMap[entry.name] = "optional";
         } else {
           interfaceMap[entry.name] = true;
         }
@@ -272,17 +275,21 @@ function runTest(version, userAgent) {
     if (!/^[A-Z]/.test(name)) {
       continue;
     }
-    ok(interfaceMap[name],
+    ok(interfaceMap[name] === "optional" || interfaceMap[name],
        "If this is failing: DANGER, are you sure you want to expose the new interface " + name +
        " to all webpages as a property on the service worker? Do not make a change to this file without a " +
        " review from a DOM peer for that specific change!!! (or a JS peer for changes to ecmaGlobals)");
     delete interfaceMap[name];
   }
   for (var name of Object.keys(interfaceMap)) {
-    ok(name in self === interfaceMap[name],
-       name + " should " + (interfaceMap[name] ? "" : " NOT") + " be defined on the global scope");
-    if (!interfaceMap[name]) {
+    if (interfaceMap[name] === "optional") {
       delete interfaceMap[name];
+    } else {
+      ok(name in self === interfaceMap[name],
+         name + " should " + (interfaceMap[name] ? "" : " NOT") + " be defined on the global scope");
+      if (!interfaceMap[name]) {
+        delete interfaceMap[name];
+      }
     }
   }
   is(Object.keys(interfaceMap).length, 0,
diff --git a/dom/workers/test/test_worker_interfaces.js b/dom/workers/test/test_worker_interfaces.js
index 694d99732929..e230f3ccf801 100644
--- a/dom/workers/test/test_worker_interfaces.js
+++ b/dom/workers/test/test_worker_interfaces.js
@@ -69,6 +69,7 @@ var ecmaGlobals =
     "URIError",
     "WeakMap",
     "WeakSet",
+    {name: "WebAssembly", optional: true}
   ];
 // IMPORTANT: Do not change the list above without review from
 //            a JavaScript Engine peer!
@@ -266,6 +267,8 @@ function createInterfaceMap(version, userAgent) {
             (entry.release === !isRelease) ||
             entry.disabled) {
           interfaceMap[entry.name] = false;
+        } else if (entry.optional) {
+          interfaceMap[entry.name] = "optional";
         } else {
           interfaceMap[entry.name] = true;
         }
@@ -286,17 +289,21 @@ function runTest(version, userAgent) {
     if (!/^[A-Z]/.test(name)) {
       continue;
     }
-    ok(interfaceMap[name],
+    ok(interfaceMap[name] === "optional" || interfaceMap[name],
        "If this is failing: DANGER, are you sure you want to expose the new interface " + name +
        " to all webpages as a property on the worker? Do not make a change to this file without a " +
        " review from a DOM peer for that specific change!!! (or a JS peer for changes to ecmaGlobals)");
     delete interfaceMap[name];
   }
   for (var name of Object.keys(interfaceMap)) {
-    ok(name in self === interfaceMap[name],
-       name + " should " + (interfaceMap[name] ? "" : " NOT") + " be defined on the global scope");
-    if (!interfaceMap[name]) {
+    if (interfaceMap[name] === "optional") {
       delete interfaceMap[name];
+    } else {
+      ok(name in self === interfaceMap[name],
+         name + " should " + (interfaceMap[name] ? "" : " NOT") + " be defined on the global scope");
+      if (!interfaceMap[name]) {
+        delete interfaceMap[name];
+      }
     }
   }
   is(Object.keys(interfaceMap).length, 0,
diff --git a/gfx/2d/SourceSurfaceSkia.cpp b/gfx/2d/SourceSurfaceSkia.cpp
index 3f242eaf9356..186e3b8c1c48 100644
--- a/gfx/2d/SourceSurfaceSkia.cpp
+++ b/gfx/2d/SourceSurfaceSkia.cpp
@@ -41,10 +41,10 @@ SourceSurfaceSkia::GetFormat() const
 }
 
 static sk_sp<SkData>
-MakeSkData(unsigned char* aData, const IntSize& aSize, int32_t aStride)
+MakeSkData(void* aData, int32_t aHeight, size_t aStride)
 {
   CheckedInt<size_t> size = aStride;
-  size *= aSize.height;
+  size *= aHeight;
   if (size.isValid()) {
     void* mem = sk_malloc_flags(size.value(), 0);
     if (mem) {
@@ -57,13 +57,24 @@ MakeSkData(unsigned char* aData, const IntSize& aSize, int32_t aStride)
   return nullptr;
 }
 
+static sk_sp<SkImage>
+ReadSkImage(const sk_sp<SkImage>& aImage, const SkImageInfo& aInfo, size_t aStride)
+{
+  if (sk_sp<SkData> data = MakeSkData(nullptr, aInfo.height(), aStride)) {
+    if (aImage->readPixels(aInfo, data->writable_data(), aStride, 0, 0, SkImage::kDisallow_CachingHint)) {
+      return SkImage::MakeRasterData(aInfo, data, aStride);
+    }
+  }
+  return nullptr;
+}
+
 bool
 SourceSurfaceSkia::InitFromData(unsigned char* aData,
                                 const IntSize &aSize,
                                 int32_t aStride,
                                 SurfaceFormat aFormat)
 {
-  sk_sp<SkData> data = MakeSkData(aData, aSize, aStride);
+  sk_sp<SkData> data = MakeSkData(aData, aSize.height, aStride);
   if (!data) {
     return false;
   }
@@ -125,16 +136,12 @@ SourceSurfaceSkia::InitFromImage(const sk_sp<SkImage>& aImage,
 uint8_t*
 SourceSurfaceSkia::GetData()
 {
+  if (!mImage) {
+    return nullptr;
+  }
 #ifdef USE_SKIA_GPU
   if (mImage->isTextureBacked()) {
-    sk_sp<SkImage> raster;
-    if (sk_sp<SkData> data = MakeSkData(nullptr, mSize, mStride)) {
-      SkImageInfo info = MakeSkiaImageInfo(mSize, mFormat);
-      if (mImage->readPixels(info, data->writable_data(), mStride, 0, 0, SkImage::kDisallow_CachingHint)) {
-        raster = SkImage::MakeRasterData(info, data, mStride);
-      }
-    }
-    if (raster) {
+    if (sk_sp<SkImage> raster = ReadSkImage(mImage, MakeSkiaImageInfo(mSize, mFormat), mStride)) {
       mImage = raster;
     } else {
       gfxCriticalError() << "Failed making Skia raster image for GPU surface";
@@ -159,7 +166,7 @@ SourceSurfaceSkia::DrawTargetWillChange()
     // don't need to do anything for them here.
     SkPixmap pixmap;
     if (mImage->peekPixels(&pixmap)) {
-      mImage = SkImage::MakeRasterCopy(pixmap);
+      mImage = ReadSkImage(mImage, pixmap.info(), pixmap.rowBytes());
       if (!mImage) {
         gfxCriticalError() << "Failed copying Skia raster snapshot";
       }
diff --git a/gfx/layers/SourceSurfaceSharedData.h b/gfx/layers/SourceSurfaceSharedData.h
index 9a26ed26f5cd..d8557eb466b8 100644
--- a/gfx/layers/SourceSurfaceSharedData.h
+++ b/gfx/layers/SourceSurfaceSharedData.h
@@ -104,7 +104,8 @@ public:
 
   /**
    * Indicates the buffer is not expected to be shared with any more processes.
-   * May release the handle if possible (see CloseHandleInternal). */
+   * May release the handle if possible (see CloseHandleInternal).
+   */
   void FinishedSharing()
   {
     MutexAutoLock lock(mMutex);
@@ -112,6 +113,17 @@ public:
     CloseHandleInternal();
   }
 
+  /**
+   * Indicates whether or not the buffer can be shared with another process
+   * without reallocating. Note that this is racy and should only be used for
+   * informational/reporting purposes.
+   */
+  bool CanShare() const
+  {
+    MutexAutoLock lock(mMutex);
+    return !mClosed;
+  }
+
   /**
    * Allocate a new shared memory buffer so that we can get a new handle for
    * sharing to new processes. ShareToProcess must have failed with
@@ -150,7 +162,7 @@ private:
    */
   void CloseHandleInternal();
 
-  Mutex mMutex;
+  mutable Mutex mMutex;
   int32_t mStride;
   int32_t mMapCount;
   IntSize mSize;
diff --git a/gfx/ots/README.mozilla b/gfx/ots/README.mozilla
index b96826735f49..54262bc46cf6 100644
--- a/gfx/ots/README.mozilla
+++ b/gfx/ots/README.mozilla
@@ -2,7 +2,7 @@ This is the Sanitiser for OpenType project, from http://code.google.com/p/ots/.
 
 Our reference repository is https://github.com/khaledhosny/ots/.
 
-Current revision: ba8417620956a920ed1f05a2f666fb6317fb10cb
+Current revision: ba8417620956a920ed1f05a2f666fb6317fb10cb (5.1.0)
 
 Upstream files included: LICENSE, src/, include/
 
diff --git a/gfx/ots/sync.sh b/gfx/ots/sync.sh
index 5a7e54b0a9d8..392e8af8208e 100755
--- a/gfx/ots/sync.sh
+++ b/gfx/ots/sync.sh
@@ -22,7 +22,8 @@ cp -r $1/include .
 
 echo "Updating README.mozilla..."
 REVISION=`cd $1; git log | head -1 | sed "s/commit //"`
-sed -e "s/\(Current revision: \).*/\1$REVISION/" README.mozilla > README.tmp
+VERSION=`cd $1; git describe | cut -d '-' -f 1 | sed 's/v//'`
+sed -e "s/\(Current revision: \).*/\1$REVISION \($VERSION\)/" README.mozilla > README.tmp
 mv README.tmp README.mozilla
 
 echo "Applying ots-visibility.patch..."
diff --git a/gfx/thebes/gfxPrefs.h b/gfx/thebes/gfxPrefs.h
index d1c58a5b6804..4d903c87e806 100644
--- a/gfx/thebes/gfxPrefs.h
+++ b/gfx/thebes/gfxPrefs.h
@@ -461,6 +461,7 @@ private:
   DECL_GFX_PREF(Live, "layers.advanced.bullet-layers",         LayersAllowBulletLayers, bool, false);
   DECL_GFX_PREF(Live, "layers.advanced.caret-layers",          LayersAllowCaretLayers, bool, false);
   DECL_GFX_PREF(Live, "layers.advanced.boxshadow-outer-layers", LayersAllowOuterBoxShadow, bool, false);
+  DECL_GFX_PREF(Live, "layers.advanced.outline-layers",        LayersAllowOutlineLayers, bool, false);
   DECL_GFX_PREF(Once, "layers.allow-d3d9-fallback",            LayersAllowD3D9Fallback, bool, false);
   DECL_GFX_PREF(Once, "layers.amd-switchable-gfx.enabled",     LayersAMDSwitchableGfxEnabled, bool, false);
   DECL_GFX_PREF(Once, "layers.async-pan-zoom.enabled",         AsyncPanZoomEnabledDoNotUseDirectly, bool, true);
diff --git a/image/AnimationSurfaceProvider.cpp b/image/AnimationSurfaceProvider.cpp
index 6487ff35e6e9..5c34f21ba231 100644
--- a/image/AnimationSurfaceProvider.cpp
+++ b/image/AnimationSurfaceProvider.cpp
@@ -118,7 +118,8 @@ AnimationSurfaceProvider::LogicalSizeInBytes() const
 void
 AnimationSurfaceProvider::AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
                                                  size_t& aHeapSizeOut,
-                                                 size_t& aNonHeapSizeOut)
+                                                 size_t& aNonHeapSizeOut,
+                                                 size_t& aSharedHandlesOut)
 {
   // Note that the surface cache lock is already held here, and then we acquire
   // mFramesMutex. For this method, this ordering is unavoidable, which means
@@ -126,7 +127,8 @@ AnimationSurfaceProvider::AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
   MutexAutoLock lock(mFramesMutex);
 
   for (const RawAccessFrameRef& frame : mFrames) {
-    frame->AddSizeOfExcludingThis(aMallocSizeOf, aHeapSizeOut, aNonHeapSizeOut);
+    frame->AddSizeOfExcludingThis(aMallocSizeOf, aHeapSizeOut,
+                                  aNonHeapSizeOut, aSharedHandlesOut);
   }
 }
 
diff --git a/image/AnimationSurfaceProvider.h b/image/AnimationSurfaceProvider.h
index bf87f37ac4c9..b0e2213195a1 100644
--- a/image/AnimationSurfaceProvider.h
+++ b/image/AnimationSurfaceProvider.h
@@ -47,7 +47,8 @@ public:
   size_t LogicalSizeInBytes() const override;
   void AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
                               size_t& aHeapSizeOut,
-                              size_t& aNonHeapSizeOut) override;
+                              size_t& aNonHeapSizeOut,
+                              size_t& aSharedHandlesOut) override;
 
 protected:
   DrawableFrameRef DrawableRef(size_t aFrame) override;
diff --git a/image/Decoder.cpp b/image/Decoder.cpp
index edfe3dfaf3a9..6f6a2f3a50d8 100644
--- a/image/Decoder.cpp
+++ b/image/Decoder.cpp
@@ -335,7 +335,8 @@ Decoder::AllocateFrameInternal(uint32_t aFrameNum,
   NotNull<RefPtr<imgFrame>> frame = WrapNotNull(new imgFrame());
   bool nonPremult = bool(mSurfaceFlags & SurfaceFlags::NO_PREMULTIPLY_ALPHA);
   if (NS_FAILED(frame->InitForDecoder(aOutputSize, aFrameRect, aFormat,
-                                      aPaletteDepth, nonPremult))) {
+                                      aPaletteDepth, nonPremult,
+                                      aFrameNum > 0))) {
     NS_WARNING("imgFrame::Init should succeed");
     return RawAccessFrameRef();
   }
diff --git a/image/FrameAnimator.cpp b/image/FrameAnimator.cpp
index d1cc0ab085a0..cf1e782a9b52 100644
--- a/image/FrameAnimator.cpp
+++ b/image/FrameAnimator.cpp
@@ -353,10 +353,11 @@ DoCollectSizeOfCompositingSurfaces(const RawAccessFrameRef& aSurface,
   SurfaceMemoryCounter counter(key, /* aIsLocked = */ true, aType);
 
   // Extract the surface's memory usage information.
-  size_t heap = 0, nonHeap = 0;
-  aSurface->AddSizeOfExcludingThis(aMallocSizeOf, heap, nonHeap);
+  size_t heap = 0, nonHeap = 0, handles = 0;
+  aSurface->AddSizeOfExcludingThis(aMallocSizeOf, heap, nonHeap, handles);
   counter.Values().SetDecodedHeap(heap);
   counter.Values().SetDecodedNonHeap(nonHeap);
+  counter.Values().SetSharedHandles(handles);
 
   // Record it.
   aCounters.AppendElement(counter);
diff --git a/image/ISurfaceProvider.h b/image/ISurfaceProvider.h
index 3b0aa3710588..e98afe229d94 100644
--- a/image/ISurfaceProvider.h
+++ b/image/ISurfaceProvider.h
@@ -64,14 +64,16 @@ public:
   /// implementation is appropriate for static ISurfaceProviders.
   virtual void AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
                                       size_t& aHeapSizeOut,
-                                      size_t& aNonHeapSizeOut)
+                                      size_t& aNonHeapSizeOut,
+                                      size_t& aSharedHandlesOut)
   {
     DrawableFrameRef ref = DrawableRef(/* aFrame = */ 0);
     if (!ref) {
       return;
     }
 
-    ref->AddSizeOfExcludingThis(aMallocSizeOf, aHeapSizeOut, aNonHeapSizeOut);
+    ref->AddSizeOfExcludingThis(aMallocSizeOf, aHeapSizeOut,
+                                aNonHeapSizeOut, aSharedHandlesOut);
   }
 
   /// @return the availability state of this ISurfaceProvider, which indicates
diff --git a/image/Image.h b/image/Image.h
index 8656b569f78c..5efa957ef4b3 100644
--- a/image/Image.h
+++ b/image/Image.h
@@ -33,6 +33,7 @@ struct MemoryCounter
     : mSource(0)
     , mDecodedHeap(0)
     , mDecodedNonHeap(0)
+    , mSharedHandles(0)
   { }
 
   void SetSource(size_t aCount) { mSource = aCount; }
@@ -41,12 +42,15 @@ struct MemoryCounter
   size_t DecodedHeap() const { return mDecodedHeap; }
   void SetDecodedNonHeap(size_t aCount) { mDecodedNonHeap = aCount; }
   size_t DecodedNonHeap() const { return mDecodedNonHeap; }
+  void SetSharedHandles(size_t aCount) { mSharedHandles = aCount; }
+  size_t SharedHandles() const { return mSharedHandles; }
 
   MemoryCounter& operator+=(const MemoryCounter& aOther)
   {
     mSource += aOther.mSource;
     mDecodedHeap += aOther.mDecodedHeap;
     mDecodedNonHeap += aOther.mDecodedNonHeap;
+    mSharedHandles += aOther.mSharedHandles;
     return *this;
   }
 
@@ -54,6 +58,7 @@ private:
   size_t mSource;
   size_t mDecodedHeap;
   size_t mDecodedNonHeap;
+  size_t mSharedHandles;
 };
 
 enum class SurfaceMemoryCounterType
diff --git a/image/SurfaceCache.cpp b/image/SurfaceCache.cpp
index dd8982ce97f2..5e7bed4a5015 100644
--- a/image/SurfaceCache.cpp
+++ b/image/SurfaceCache.cpp
@@ -197,10 +197,12 @@ public:
       // for surfaces with PlaybackType::eAnimated.)
       size_t heap = 0;
       size_t nonHeap = 0;
+      size_t handles = 0;
       aCachedSurface->mProvider
-        ->AddSizeOfExcludingThis(mMallocSizeOf, heap, nonHeap);
+        ->AddSizeOfExcludingThis(mMallocSizeOf, heap, nonHeap, handles);
       counter.Values().SetDecodedHeap(heap);
       counter.Values().SetDecodedNonHeap(nonHeap);
+      counter.Values().SetSharedHandles(handles);
 
       mCounters.AppendElement(counter);
     }
diff --git a/image/imgFrame.cpp b/image/imgFrame.cpp
index db31c04989da..f5d6c675759c 100644
--- a/image/imgFrame.cpp
+++ b/image/imgFrame.cpp
@@ -932,7 +932,8 @@ imgFrame::SetCompositingFailed(bool val)
 void
 imgFrame::AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
                                  size_t& aHeapSizeOut,
-                                 size_t& aNonHeapSizeOut) const
+                                 size_t& aNonHeapSizeOut,
+                                 size_t& aSharedHandlesOut) const
 {
   MonitorAutoLock lock(mMonitor);
 
@@ -949,6 +950,14 @@ imgFrame::AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
     aHeapSizeOut += aMallocSizeOf(mRawSurface);
     mRawSurface->AddSizeOfExcludingThis(aMallocSizeOf, aHeapSizeOut,
                                         aNonHeapSizeOut);
+
+    if (mRawSurface->GetType() == SurfaceType::DATA_SHARED) {
+      auto sharedSurface =
+        static_cast<SourceSurfaceSharedData*>(mRawSurface.get());
+      if (sharedSurface->CanShare()) {
+        ++aSharedHandlesOut;
+      }
+    }
   }
 }
 
diff --git a/image/imgFrame.h b/image/imgFrame.h
index b940777fa81e..34d19447620a 100644
--- a/image/imgFrame.h
+++ b/image/imgFrame.h
@@ -348,7 +348,8 @@ public:
   already_AddRefed<SourceSurface> GetSourceSurface();
 
   void AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf, size_t& aHeapSizeOut,
-                              size_t& aNonHeapSizeOut) const;
+                              size_t& aNonHeapSizeOut,
+                              size_t& aSharedHandlesOut) const;
 
 private: // methods
 
diff --git a/image/imgLoader.cpp b/image/imgLoader.cpp
index 68facd72c51c..8daee793674c 100644
--- a/image/imgLoader.cpp
+++ b/image/imgLoader.cpp
@@ -280,6 +280,11 @@ private:
       surfacePathPrefix.Append("x");
       surfacePathPrefix.AppendInt(counter.Key().Size().height);
 
+      if (counter.Values().SharedHandles() > 0) {
+        surfacePathPrefix.Append(", shared:");
+        surfacePathPrefix.AppendInt(uint32_t(counter.Values().SharedHandles()));
+      }
+
       if (counter.Type() == SurfaceMemoryCounterType::NORMAL) {
         PlaybackType playback = counter.Key().Playback();
         surfacePathPrefix.Append(playback == PlaybackType::eAnimated
diff --git a/js/src/builtin/AtomicsObject.cpp b/js/src/builtin/AtomicsObject.cpp
index f710a95863be..298c273cbbbb 100644
--- a/js/src/builtin/AtomicsObject.cpp
+++ b/js/src/builtin/AtomicsObject.cpp
@@ -84,8 +84,8 @@ ReportBadArrayType(JSContext* cx)
 static bool
 ReportOutOfRange(JSContext* cx)
 {
-    // Use JSMSG_BAD_INDEX here even if it is generic, since that is
-    // the message used by NonStandardToIndex for its initial range checking.
+    // Use JSMSG_BAD_INDEX here, it is what ToIndex uses for some cases that it
+    // reports directly.
     JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_INDEX);
     return false;
 }
@@ -115,7 +115,7 @@ static bool
 GetTypedArrayIndex(JSContext* cx, HandleValue v, Handle<TypedArrayObject*> view, uint32_t* offset)
 {
     uint64_t index;
-    if (!NonStandardToIndex(cx, v, &index))
+    if (!ToIndex(cx, v, &index))
         return false;
     if (index >= view->length())
         return ReportOutOfRange(cx);
diff --git a/js/src/builtin/Module.js b/js/src/builtin/Module.js
index ced9630e9f1f..c9fafbcbd916 100644
--- a/js/src/builtin/Module.js
+++ b/js/src/builtin/Module.js
@@ -65,12 +65,12 @@ function ModuleGetExportedNames(exportStarSet = [])
     return exportedNames;
 }
 
-// 15.2.1.16.3 ResolveExport(exportName, resolveSet, exportStarSet)
-function ModuleResolveExport(exportName, resolveSet = [], exportStarSet = [])
+// 15.2.1.16.3 ResolveExport(exportName, resolveSet)
+function ModuleResolveExport(exportName, resolveSet = [])
 {
     if (!IsObject(this) || !IsModule(this)) {
         return callFunction(CallModuleMethodIfWrapped, this, exportName, resolveSet,
-                            exportStarSet, "ModuleResolveExport");
+                            "ModuleResolveExport");
     }
 
     // Step 1
@@ -100,38 +100,29 @@ function ModuleResolveExport(exportName, resolveSet = [], exportStarSet = [])
         let e = indirectExportEntries[i];
         if (exportName === e.exportName) {
             let importedModule = CallModuleResolveHook(module, e.moduleRequest,
-                                                       MODULE_STATE_INSTANTIATED);
-            let indirectResolution = callFunction(importedModule.resolveExport, importedModule,
-                                                  e.importName, resolveSet, exportStarSet);
-            if (indirectResolution !== null)
-                return indirectResolution;
+                                                       MODULE_STATE_PARSED);
+            return callFunction(importedModule.resolveExport, importedModule, e.importName,
+                                resolveSet);
         }
     }
 
     // Step 6
     if (exportName === "default") {
         // A default export cannot be provided by an export *.
-        ThrowSyntaxError(JSMSG_BAD_DEFAULT_EXPORT);
+        return null;
     }
 
     // Step 7
-    if (callFunction(ArrayIncludes, exportStarSet, module))
-        return null;
-
-    // Step 8
-    _DefineDataProperty(exportStarSet, exportStarSet.length, module);
-
-    // Step 9
     let starResolution = null;
 
-    // Step 10
+    // Step 8
     let starExportEntries = module.starExportEntries;
     for (let i = 0; i < starExportEntries.length; i++) {
         let e = starExportEntries[i];
         let importedModule = CallModuleResolveHook(module, e.moduleRequest,
-                                                   MODULE_STATE_INSTANTIATED);
+                                                   MODULE_STATE_PARSED);
         let resolution = callFunction(importedModule.resolveExport, importedModule,
-                                      exportName, resolveSet, exportStarSet);
+                                      exportName, resolveSet);
         if (resolution === "ambiguous")
             return resolution;
 
@@ -148,6 +139,7 @@ function ModuleResolveExport(exportName, resolveSet = [], exportStarSet = [])
         }
     }
 
+    // Step 9
     return starResolution;
 }
 
@@ -213,8 +205,8 @@ function GetModuleEnvironment(module)
 
 function RecordInstantationFailure(module)
 {
-    // Set the module's environment slot to 'null' to indicate a failed module
-    // instantiation.
+    // Set the module's state to 'failed' to indicate a failed module
+    // instantiation and reset the environment slot to 'undefined'.
     assert(IsModule(module), "Non-module passed to RecordInstantationFailure");
     SetModuleState(module, MODULE_STATE_FAILED);
     UnsafeSetReservedSlot(module, MODULE_OBJECT_ENVIRONMENT_SLOT, undefined);
@@ -275,11 +267,13 @@ function ModuleDeclarationInstantiation()
                     ThrowSyntaxError(JSMSG_MISSING_IMPORT, imp.importName);
                 if (resolution === "ambiguous")
                     ThrowSyntaxError(JSMSG_AMBIGUOUS_IMPORT, imp.importName);
+                if (resolution.module.state < MODULE_STATE_INSTANTIATED)
+                    ThrowInternalError(JSMSG_BAD_MODULE_STATE);
                 CreateImportBinding(env, imp.localName, resolution.module, resolution.bindingName);
             }
         }
 
-        // Step 16.iv
+        // Step 17.a.iii
         InstantiateModuleFunctionDeclarations(module);
     } catch (e) {
         RecordInstantationFailure(module);
diff --git a/js/src/builtin/ModuleObject.cpp b/js/src/builtin/ModuleObject.cpp
index dc9cf3bd884d..5f15014d30da 100644
--- a/js/src/builtin/ModuleObject.cpp
+++ b/js/src/builtin/ModuleObject.cpp
@@ -994,7 +994,7 @@ GlobalObject::initModuleProto(JSContext* cx, Handle<GlobalObject*> global)
 
     static const JSFunctionSpec protoFunctions[] = {
         JS_SELF_HOSTED_FN("getExportedNames", "ModuleGetExportedNames", 1, 0),
-        JS_SELF_HOSTED_FN("resolveExport", "ModuleResolveExport", 3, 0),
+        JS_SELF_HOSTED_FN("resolveExport", "ModuleResolveExport", 2, 0),
         JS_SELF_HOSTED_FN("declarationInstantiation", "ModuleDeclarationInstantiation", 0, 0),
         JS_SELF_HOSTED_FN("evaluation", "ModuleEvaluation", 0, 0),
         JS_FS_END
diff --git a/js/src/devtools/rootAnalysis/annotations.js b/js/src/devtools/rootAnalysis/annotations.js
index 7e92b89b90de..1ca950e9e92b 100644
--- a/js/src/devtools/rootAnalysis/annotations.js
+++ b/js/src/devtools/rootAnalysis/annotations.js
@@ -160,6 +160,7 @@ function isSuppressedVirtualMethod(csu, method)
 var ignoreFunctions = {
     "ptio.c:pt_MapError" : true,
     "je_malloc_printf" : true,
+    "malloc_usable_size" : true,
     "vprintf_stderr" : true,
     "PR_ExplodeTime" : true,
     "PR_ErrorInstallTable" : true,
diff --git a/js/src/ds/Bitmap.cpp b/js/src/ds/Bitmap.cpp
new file mode 100644
index 000000000000..4cc698c3e375
--- /dev/null
+++ b/js/src/ds/Bitmap.cpp
@@ -0,0 +1,130 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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 "ds/Bitmap.h"
+
+using namespace js;
+
+SparseBitmap::~SparseBitmap()
+{
+    if (data.initialized()) {
+        for (Data::Range r(data.all()); !r.empty(); r.popFront())
+            js_delete(r.front().value());
+    }
+}
+
+size_t
+SparseBitmap::sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf)
+{
+    size_t size = data.sizeOfExcludingThis(mallocSizeOf);
+    for (Data::Range r(data.all()); !r.empty(); r.popFront())
+        size += mallocSizeOf(r.front().value());
+    return size;
+}
+
+SparseBitmap::BitBlock&
+SparseBitmap::getOrCreateBlock(size_t blockId)
+{
+    Data::AddPtr p = data.lookupForAdd(blockId);
+    if (!p) {
+        AutoEnterOOMUnsafeRegion oomUnsafe;
+        BitBlock* block = js_new<BitBlock>();
+        if (!block || !data.add(p, blockId, block))
+            oomUnsafe.crash("Bitmap OOM");
+        PodZero(block);
+    }
+    return *p->value();
+}
+
+void
+SparseBitmap::setBit(size_t bit)
+{
+    size_t word = bit / JS_BITS_PER_WORD;
+    size_t blockWord = blockStartWord(word);
+    BitBlock& block = getOrCreateBlock(blockWord / WordsInBlock);
+    block[word - blockWord] |= uintptr_t(1) << (bit % JS_BITS_PER_WORD);
+}
+
+SparseBitmap::BitBlock*
+SparseBitmap::getBlock(size_t blockId) const
+{
+    Data::Ptr p = data.lookup(blockId);
+    return p ? p->value() : nullptr;
+}
+
+bool
+SparseBitmap::getBit(size_t bit) const
+{
+    size_t word = bit / JS_BITS_PER_WORD;
+    size_t blockWord = blockStartWord(word);
+
+    BitBlock* block = getBlock(blockWord / WordsInBlock);
+    if (block)
+        return (*block)[word - blockWord] & (uintptr_t(1) << (bit % JS_BITS_PER_WORD));
+    return false;
+}
+
+void
+SparseBitmap::bitwiseAndWith(const DenseBitmap& other)
+{
+    for (Data::Enum e(data); !e.empty(); e.popFront()) {
+        BitBlock& block = *e.front().value();
+        size_t blockWord = e.front().key() * WordsInBlock;
+        bool anySet = false;
+        size_t numWords = wordIntersectCount(blockWord, other);
+        for (size_t i = 0; i < numWords; i++) {
+            block[i] &= other.word(blockWord + i);
+            anySet |= !!block[i];
+        }
+        if (!anySet) {
+            js_delete(&block);
+            e.removeFront();
+        }
+    }
+}
+
+void
+SparseBitmap::bitwiseOrWith(const SparseBitmap& other)
+{
+    for (Data::Range r(other.data.all()); !r.empty(); r.popFront()) {
+        const BitBlock& otherBlock = *r.front().value();
+        BitBlock& block = getOrCreateBlock(r.front().key());
+        for (size_t i = 0; i < WordsInBlock; i++)
+            block[i] |= otherBlock[i];
+    }
+}
+
+void
+SparseBitmap::bitwiseOrInto(DenseBitmap& other) const
+{
+    for (Data::Range r(data.all()); !r.empty(); r.popFront()) {
+        BitBlock& block = *r.front().value();
+        size_t blockWord = r.front().key() * WordsInBlock;
+        size_t numWords = wordIntersectCount(blockWord, other);
+#ifdef DEBUG
+        // Any words out of range in other should be zero in this bitmap.
+        for (size_t i = numWords; i < WordsInBlock; i++)
+            MOZ_ASSERT(!block[i]);
+#endif
+        for (size_t i = 0; i < numWords; i++)
+            other.word(blockWord + i) |= block[i];
+    }
+}
+
+void
+SparseBitmap::bitwiseOrRangeInto(size_t wordStart, size_t numWords, uintptr_t* target) const
+{
+    size_t blockWord = blockStartWord(wordStart);
+
+    // We only support using a single bit block in this API.
+    MOZ_ASSERT(numWords && (blockWord == blockStartWord(wordStart + numWords - 1)));
+
+    BitBlock* block = getBlock(blockWord / WordsInBlock);
+    if (block) {
+        for (size_t i = 0; i < numWords; i++)
+            target[i] |= (*block)[wordStart - blockWord + i];
+    }
+}
diff --git a/js/src/ds/Bitmap.h b/js/src/ds/Bitmap.h
new file mode 100644
index 000000000000..2b0239e8b66a
--- /dev/null
+++ b/js/src/ds/Bitmap.h
@@ -0,0 +1,103 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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 ds_Bitmap_h
+#define ds_Bitmap_h
+
+#include <algorithm>
+
+#include "jsalloc.h"
+
+#include "js/HashTable.h"
+#include "js/Vector.h"
+
+// This file provides two classes for representing bitmaps.
+//
+// DenseBitmap is an array of words of bits, with size linear in the maximum
+// bit which has been set on it.
+//
+// SparseBitmap provides a reasonably simple, reasonably efficient (in time and
+// space) implementation of a sparse bitmap. The basic representation is a hash
+// table whose entries are fixed length malloc'ed blocks of bits.
+
+namespace js {
+
+class DenseBitmap
+{
+    typedef Vector<uintptr_t, 0, SystemAllocPolicy> Data;
+    Data data;
+
+  public:
+    size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) {
+        return data.sizeOfExcludingThis(mallocSizeOf);
+    }
+
+    bool ensureSpace(size_t numWords) {
+        MOZ_ASSERT(data.empty());
+        return data.appendN(0, numWords);
+    }
+
+    size_t numWords() const { return data.length(); }
+    uintptr_t word(size_t i) const { return data[i]; }
+    uintptr_t& word(size_t i) { return data[i]; }
+
+    void copyBitsFrom(size_t wordStart, size_t numWords, uintptr_t* source) {
+        MOZ_ASSERT(wordStart + numWords <= data.length());
+        mozilla::PodCopy(&data[wordStart], source, numWords);
+    }
+
+    void bitwiseOrRangeInto(size_t wordStart, size_t numWords, uintptr_t* target) const {
+        for (size_t i = 0; i < numWords; i++)
+            target[i] |= data[wordStart + i];
+    }
+};
+
+class SparseBitmap
+{
+    // The number of words of bits to use for each block mainly affects the
+    // memory usage of the bitmap. To minimize overhead, bitmaps which are
+    // expected to be fairly dense should have a large block size, and bitmaps
+    // which are expected to be very sparse should have a small block size.
+    static const size_t WordsInBlock = 4096 / sizeof(uintptr_t);
+
+    typedef mozilla::Array<uintptr_t, WordsInBlock> BitBlock;
+    typedef HashMap<size_t, BitBlock*, DefaultHasher<size_t>, SystemAllocPolicy> Data;
+    Data data;
+
+    static size_t blockStartWord(size_t word) {
+        return word & ~(WordsInBlock - 1);
+    }
+
+    // Return the number of words in a BitBlock starting at |blockWord| which
+    // are in |other|.
+    static size_t wordIntersectCount(size_t blockWord, const DenseBitmap& other) {
+        long count = other.numWords() - blockWord;
+        return std::min<size_t>((size_t)WordsInBlock, std::max<long>(count, 0));
+    }
+
+    BitBlock* getBlock(size_t blockId) const;
+    BitBlock& getOrCreateBlock(size_t blockId);
+
+  public:
+    bool init() { return data.init(); }
+    ~SparseBitmap();
+
+    size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf);
+
+    void setBit(size_t bit);
+    bool getBit(size_t bit) const;
+
+    void bitwiseAndWith(const DenseBitmap& other);
+    void bitwiseOrWith(const SparseBitmap& other);
+    void bitwiseOrInto(DenseBitmap& other) const;
+
+    // Currently, this API only supports a range of words that is in a single bit block.
+    void bitwiseOrRangeInto(size_t wordStart, size_t numWords, uintptr_t* target) const;
+};
+
+} // namespace js
+
+#endif // ds_Bitmap_h
diff --git a/js/src/ds/PageProtectingVector.h b/js/src/ds/PageProtectingVector.h
index acd1440cb967..cf3bcd47b18a 100644
--- a/js/src/ds/PageProtectingVector.h
+++ b/js/src/ds/PageProtectingVector.h
@@ -8,13 +8,27 @@
 #define ds_PageProtectingVector_h
 
 #include "mozilla/Atomics.h"
+#include "mozilla/IntegerPrintfMacros.h"
 #include "mozilla/PodOperations.h"
+#include "mozilla/Types.h"
 #include "mozilla/Vector.h"
 
+#ifdef MALLOC_H
+# include MALLOC_H
+#endif
+
 #include "ds/MemoryProtectionExceptionHandler.h"
 #include "gc/Memory.h"
 #include "js/Utility.h"
 
+#ifdef MOZ_MEMORY
+# ifdef XP_DARWIN
+#  define malloc_usable_size malloc_size
+# else
+extern "C" MFBT_API size_t malloc_usable_size(MALLOC_USABLE_SIZE_CONST_PTR void* p);
+# endif
+#endif
+
 namespace js {
 
 /*
@@ -455,23 +469,82 @@ PageProtectingVector<T, A, B, C, D, E, F, G>::appendSlow(const U* values, size_t
 
 class ProtectedReallocPolicy
 {
+    uintptr_t currAddr;
+    size_t currSize;
+    uintptr_t prevAddr;
+    size_t prevSize;
+
+    template <typename T> void update(T* newAddr, size_t newSize) {
+        prevAddr = currAddr;
+        prevSize = currSize;
+        currAddr = uintptr_t(newAddr);
+        currSize = newSize * sizeof(T);
+    }
+
+    template <typename T> void updateIfValid(T* newAddr, size_t newSize) {
+        if (newAddr)
+            update<T>(newAddr, newSize);
+    }
+
+    template <typename T> T* reallocUpdate(T* oldAddr, size_t oldSize, size_t newSize) {
+        T* newAddr = js_pod_realloc<T>(oldAddr, oldSize, newSize);
+        updateIfValid<T>(newAddr, newSize);
+        return newAddr;
+    }
+
   public:
+    ProtectedReallocPolicy() : currAddr(0), currSize(0), prevAddr(0), prevSize(0) {}
+
+    ~ProtectedReallocPolicy() {
+        MOZ_RELEASE_ASSERT(!currSize && !currAddr);
+    }
+
     template <typename T> T* maybe_pod_malloc(size_t numElems) {
-        return js_pod_malloc<T>(numElems);
+        MOZ_RELEASE_ASSERT(!currSize && !currAddr);
+        T* addr = js_pod_malloc<T>(numElems);
+        updateIfValid<T>(addr, numElems);
+        return addr;
     }
+
     template <typename T> T* maybe_pod_calloc(size_t numElems) {
-        return js_pod_calloc<T>(numElems);
+        MOZ_RELEASE_ASSERT(!currSize && !currAddr);
+        T* addr = js_pod_calloc<T>(numElems);
+        updateIfValid<T>(addr, numElems);
+        return addr;
     }
+
     template <typename T> T* maybe_pod_realloc(T* oldAddr, size_t oldSize, size_t newSize) {
+        if (uintptr_t(oldAddr) != currAddr) {
+            MOZ_CRASH_UNSAFE_PRINTF("maybe_pod_realloc: oldAddr and currAddr don't match "
+                                    "(0x%" PRIx64 " != 0x%" PRIx64 ", %" PRIu64 ")!",
+                                    uint64_t(oldAddr), uint64_t(currAddr), uint64_t(currSize));
+        }
+        if (oldSize * sizeof(T) != currSize) {
+            MOZ_CRASH_UNSAFE_PRINTF("maybe_pod_realloc: oldSize and currSize don't match "
+                                    "(%" PRIu64 " != %" PRIu64 ", 0x%" PRIx64 ")!",
+                                    uint64_t(oldSize * sizeof(T)), uint64_t(currSize),
+                                    uint64_t(currAddr));
+        }
+
         MOZ_ASSERT_IF(oldAddr, oldSize);
         if (MOZ_UNLIKELY(!newSize))
             return nullptr;
         if (MOZ_UNLIKELY(!oldAddr))
-            return js_pod_malloc<T>(newSize);
+            return maybe_pod_malloc<T>(newSize);
+
+#ifdef MOZ_MEMORY
+        size_t usableSize = malloc_usable_size(oldAddr);
+        if (usableSize < currSize) {
+            MOZ_CRASH_UNSAFE_PRINTF("maybe_pod_realloc: usableSize < currSize "
+                                    "(%" PRIu64 " < %" PRIu64 ", %" PRIu64 ", %s)!",
+                                    uint64_t(usableSize), uint64_t(currSize),
+                                    uint64_t(prevSize), prevAddr == currAddr ? "true" : "false");
+        }
+#endif
 
         T* tmpAddr = js_pod_malloc<T>(newSize);
         if (MOZ_UNLIKELY(!tmpAddr))
-            return js_pod_realloc<T>(oldAddr, oldSize, newSize);
+            return reallocUpdate<T>(oldAddr, oldSize, newSize);
 
         size_t bytes = (newSize >= oldSize ? oldSize : newSize) * sizeof(T);
         memcpy(tmpAddr, oldAddr, bytes);
@@ -479,19 +552,27 @@ class ProtectedReallocPolicy
         T* newAddr = js_pod_realloc<T>(oldAddr, oldSize, newSize);
         if (MOZ_UNLIKELY(!newAddr)) {
             js_free(tmpAddr);
-            return js_pod_realloc<T>(oldAddr, oldSize, newSize);
+            return reallocUpdate<T>(oldAddr, oldSize, newSize);
         }
 
         const uint8_t* newAddrBytes = reinterpret_cast<const uint8_t*>(newAddr);
         const uint8_t* tmpAddrBytes = reinterpret_cast<const uint8_t*>(tmpAddr);
         if (!mozilla::PodEqual(tmpAddrBytes, newAddrBytes, bytes)) {
-            if (oldAddr == newAddr)
-                MOZ_CRASH("New buffer doesn't match the old buffer (newAddr == oldAddr)!");
-            else
-                MOZ_CRASH("New buffer doesn't match the old buffer (newAddr != oldAddr)!");
+#ifdef MOZ_MEMORY
+            MOZ_CRASH_UNSAFE_PRINTF("maybe_pod_realloc: buffers don't match "
+                                    "(%" PRIu64 " >= %" PRIu64 ", %" PRIu64 ", %s)!",
+                                    uint64_t(usableSize), uint64_t(currSize),
+                                    uint64_t(prevSize), prevAddr == currAddr ? "true" : "false");
+#else
+            MOZ_CRASH_UNSAFE_PRINTF("maybe_pod_realloc: buffers don't match "
+                                    "(%" PRIu64 ", %" PRIu64 ", %s)!",
+                                    uint64_t(currSize), uint64_t(prevSize),
+                                    prevAddr == currAddr ? "true" : "false");
+#endif
         }
 
         js_free(tmpAddr);
+        update<T>(newAddr, newSize);
         return newAddr;
     }
 
@@ -500,7 +581,22 @@ class ProtectedReallocPolicy
     template <typename T> T* pod_realloc(T* p, size_t oldSize, size_t newSize) {
         return maybe_pod_realloc<T>(p, oldSize, newSize);
     }
-    void free_(void* p) { js_free(p); }
+
+    void free_(void* p) {
+        MOZ_RELEASE_ASSERT(uintptr_t(p) == currAddr);
+#ifdef MOZ_MEMORY
+        size_t usableSize = malloc_usable_size(p);
+        if (usableSize < currSize) {
+            MOZ_CRASH_UNSAFE_PRINTF("free_: usableSize < currSize "
+                                    "(%" PRIu64 " < %" PRIu64 ", %" PRIu64 ", %s)!",
+                                    uint64_t(usableSize), uint64_t(currSize),
+                                    uint64_t(prevSize), prevAddr == currAddr ? "true" : "false");
+        }
+#endif
+        js_free(p);
+        update<uint8_t>(0, 0);
+    }
+
     void reportAllocOverflow() const {}
     bool checkSimulatedOOM() const {
         return !js::oom::ShouldFailWithOOM();
diff --git a/js/src/gc/AtomMarking.cpp b/js/src/gc/AtomMarking.cpp
index ae01e2a8bb8c..affb78d4c264 100644
--- a/js/src/gc/AtomMarking.cpp
+++ b/js/src/gc/AtomMarking.cpp
@@ -44,29 +44,6 @@ namespace gc {
 // bits for space between things being unused when things are larger than a
 // single Cell.
 
-static inline void
-SetBit(uintptr_t* bitmap, size_t bit)
-{
-    bitmap[bit / JS_BITS_PER_WORD] |= uintptr_t(1) << (bit % JS_BITS_PER_WORD);
-}
-
-static inline bool
-GetBit(uintptr_t* bitmap, size_t bit)
-{
-    return bitmap[bit / JS_BITS_PER_WORD] & (uintptr_t(1) << (bit % JS_BITS_PER_WORD));
-}
-
-static inline bool
-EnsureBitmapLength(AtomMarkingRuntime::Bitmap& bitmap, size_t nwords)
-{
-    if (nwords > bitmap.length()) {
-        size_t needed = nwords - bitmap.length();
-        if (needed)
-            return bitmap.appendN(0, needed);
-    }
-    return true;
-}
-
 void
 AtomMarkingRuntime::registerArena(Arena* arena)
 {
@@ -98,12 +75,11 @@ AtomMarkingRuntime::unregisterArena(Arena* arena)
 }
 
 bool
-AtomMarkingRuntime::computeBitmapFromChunkMarkBits(JSRuntime* runtime, Bitmap& bitmap)
+AtomMarkingRuntime::computeBitmapFromChunkMarkBits(JSRuntime* runtime, DenseBitmap& bitmap)
 {
     MOZ_ASSERT(runtime->currentThreadHasExclusiveAccess());
 
-    MOZ_ASSERT(bitmap.empty());
-    if (!EnsureBitmapLength(bitmap, allocatedWords))
+    if (!bitmap.ensureSpace(allocatedWords))
         return false;
 
     Zone* atomsZone = runtime->unsafeAtomsCompartment()->zone();
@@ -111,8 +87,7 @@ AtomMarkingRuntime::computeBitmapFromChunkMarkBits(JSRuntime* runtime, Bitmap& b
         for (ArenaIter aiter(atomsZone, thingKind); !aiter.done(); aiter.next()) {
             Arena* arena = aiter.get();
             uintptr_t* chunkWords = arena->chunk()->bitmap.arenaBits(arena);
-            uintptr_t* bitmapWords = &bitmap[arena->atomBitmapStart()];
-            mozilla::PodCopy(bitmapWords, chunkWords, ArenaBitmapWords);
+            bitmap.copyBitsFrom(arena->atomBitmapStart(), ArenaBitmapWords, chunkWords);
         }
     }
 
@@ -120,25 +95,21 @@ AtomMarkingRuntime::computeBitmapFromChunkMarkBits(JSRuntime* runtime, Bitmap& b
 }
 
 void
-AtomMarkingRuntime::updateZoneBitmap(Zone* zone, const Bitmap& bitmap)
+AtomMarkingRuntime::updateZoneBitmap(Zone* zone, const DenseBitmap& bitmap)
 {
     if (zone->isAtomsZone())
         return;
 
-    // |bitmap| was produced by computeBitmapFromChunkMarkBits, so it should
-    // have the maximum possible size.
-    MOZ_ASSERT(zone->markedAtoms().length() <= bitmap.length());
-
     // Take the bitwise and between the two mark bitmaps to get the best new
     // overapproximation we can. |bitmap| might include bits that are not in
     // the zone's mark bitmap, if additional zones were collected by the GC.
-    for (size_t i = 0; i < zone->markedAtoms().length(); i++)
-        zone->markedAtoms()[i] &= bitmap[i];
+    zone->markedAtoms().bitwiseAndWith(bitmap);
 }
 
 // Set any bits in the chunk mark bitmaps for atoms which are marked in bitmap.
+template <typename Bitmap>
 static void
-AddBitmapToChunkMarkBits(JSRuntime* runtime, AtomMarkingRuntime::Bitmap& bitmap)
+AddBitmapToChunkMarkBits(JSRuntime* runtime, Bitmap& bitmap)
 {
     // Make sure that by copying the mark bits for one arena in word sizes we
     // do not affect the mark bits for other arenas.
@@ -150,16 +121,7 @@ AddBitmapToChunkMarkBits(JSRuntime* runtime, AtomMarkingRuntime::Bitmap& bitmap)
         for (ArenaIter aiter(atomsZone, thingKind); !aiter.done(); aiter.next()) {
             Arena* arena = aiter.get();
             uintptr_t* chunkWords = arena->chunk()->bitmap.arenaBits(arena);
-
-            // The bitmap might not be long enough, in which case remaining
-            // bits are implicitly zero.
-            if (bitmap.length() <= arena->atomBitmapStart())
-                continue;
-            MOZ_ASSERT(bitmap.length() >= arena->atomBitmapStart() + ArenaBitmapWords);
-
-            uintptr_t* bitmapWords = &bitmap[arena->atomBitmapStart()];
-            for (size_t i = 0; i < ArenaBitmapWords; i++)
-                chunkWords[i] |= bitmapWords[i];
+            bitmap.bitwiseOrRangeInto(arena->atomBitmapStart(), ArenaBitmapWords, chunkWords);
         }
     }
 }
@@ -172,17 +134,14 @@ AtomMarkingRuntime::updateChunkMarkBits(JSRuntime* runtime)
     // Try to compute a simple union of the zone atom bitmaps before updating
     // the chunk mark bitmaps. If this allocation fails then fall back to
     // updating the chunk mark bitmaps separately for each zone.
-    Bitmap markedUnion;
-    if (EnsureBitmapLength(markedUnion, allocatedWords)) {
+    DenseBitmap markedUnion;
+    if (markedUnion.ensureSpace(allocatedWords)) {
         for (ZonesIter zone(runtime, SkipAtoms); !zone.done(); zone.next()) {
             // We only need to update the chunk mark bits for zones which were
             // not collected in the current GC. Atoms which are referenced by
             // collected zones have already been marked.
-            if (!zone->isCollectingFromAnyThread()) {
-                MOZ_ASSERT(zone->markedAtoms().length() <= allocatedWords);
-                for (size_t i = 0; i < zone->markedAtoms().length(); i++)
-                    markedUnion[i] |= zone->markedAtoms()[i];
-            }
+            if (!zone->isCollectingFromAnyThread())
+                zone->markedAtoms().bitwiseOrInto(markedUnion);
         }
         AddBitmapToChunkMarkBits(runtime, markedUnion);
     } else {
@@ -225,14 +184,9 @@ AtomMarkingRuntime::markAtom(JSContext* cx, TenuredCell* thing)
         return;
 
     size_t bit = GetAtomBit(thing);
+    MOZ_ASSERT(bit / JS_BITS_PER_WORD < allocatedWords);
 
-    {
-        AutoEnterOOMUnsafeRegion oomUnsafe;
-        if (!EnsureBitmapLength(cx->zone()->markedAtoms(), allocatedWords))
-            oomUnsafe.crash("Atom bitmap OOM");
-    }
-
-    SetBit(cx->zone()->markedAtoms().begin(), bit);
+    cx->zone()->markedAtoms().setBit(bit);
 
     if (!cx->helperThread()) {
         // Trigger a read barrier on the atom, in case there is an incremental
@@ -272,18 +226,7 @@ void
 AtomMarkingRuntime::adoptMarkedAtoms(Zone* target, Zone* source)
 {
     MOZ_ASSERT(target->runtimeFromAnyThread()->currentThreadHasExclusiveAccess());
-
-    Bitmap* targetBitmap = &target->markedAtoms();
-    Bitmap* sourceBitmap = &source->markedAtoms();
-    if (targetBitmap->length() < sourceBitmap->length())
-        std::swap(targetBitmap, sourceBitmap);
-    for (size_t i = 0; i < sourceBitmap->length(); i++)
-        (*targetBitmap)[i] |= (*sourceBitmap)[i];
-
-    if (targetBitmap != &target->markedAtoms())
-        target->markedAtoms() = Move(source->markedAtoms());
-    else
-        source->markedAtoms().clear();
+    target->markedAtoms().bitwiseOrWith(source->markedAtoms());
 }
 
 #ifdef DEBUG
@@ -309,9 +252,7 @@ AtomMarkingRuntime::atomIsMarked(Zone* zone, Cell* thingArg)
     }
 
     size_t bit = GetAtomBit(thing);
-    if (bit >= zone->markedAtoms().length() * JS_BITS_PER_WORD)
-        return false;
-    return GetBit(zone->markedAtoms().begin(), bit);
+    return zone->markedAtoms().getBit(bit);
 }
 
 bool
diff --git a/js/src/gc/AtomMarking.h b/js/src/gc/AtomMarking.h
index c1cccd7f4067..f0d24b9b4547 100644
--- a/js/src/gc/AtomMarking.h
+++ b/js/src/gc/AtomMarking.h
@@ -8,6 +8,7 @@
 #define gc_AtomMarking_h
 
 #include "NamespaceImports.h"
+#include "ds/Bitmap.h"
 #include "gc/Heap.h"
 #include "threading/ProtectedData.h"
 
@@ -21,13 +22,11 @@ class AtomMarkingRuntime
     // Unused arena atom bitmap indexes. Protected by the GC lock.
     js::ExclusiveAccessLockOrGCTaskData<Vector<size_t, 0, SystemAllocPolicy>> freeArenaIndexes;
 
+  public:
     // The extent of all allocated and free words in atom mark bitmaps.
     // This monotonically increases and may be read from without locking.
     mozilla::Atomic<size_t> allocatedWords;
 
-  public:
-    typedef Vector<uintptr_t, 0, SystemAllocPolicy> Bitmap;
-
     AtomMarkingRuntime()
       : allocatedWords(0)
     {}
@@ -41,11 +40,11 @@ class AtomMarkingRuntime
     // Fill |bitmap| with an atom marking bitmap based on the things that are
     // currently marked in the chunks used by atoms zone arenas. This returns
     // false on an allocation failure (but does not report an exception).
-    bool computeBitmapFromChunkMarkBits(JSRuntime* runtime, Bitmap& bitmap);
+    bool computeBitmapFromChunkMarkBits(JSRuntime* runtime, DenseBitmap& bitmap);
 
     // Update the atom marking bitmap in |zone| according to another
     // overapproximation of the reachable atoms in |bitmap|.
-    void updateZoneBitmap(Zone* zone, const Bitmap& bitmap);
+    void updateZoneBitmap(Zone* zone, const DenseBitmap& bitmap);
 
     // Set any bits in the chunk mark bitmaps for atoms which are marked in any
     // zone in the runtime.
diff --git a/js/src/gc/GCRuntime.h b/js/src/gc/GCRuntime.h
index b82c4d1d244a..0aa34dcb4637 100644
--- a/js/src/gc/GCRuntime.h
+++ b/js/src/gc/GCRuntime.h
@@ -596,6 +596,56 @@ typedef HashMap<Value*, const char*, DefaultHasher<Value*>, SystemAllocPolicy> R
 
 using AllocKinds = mozilla::EnumSet<AllocKind>;
 
+template <typename T>
+class MemoryCounter
+{
+    // Bytes counter to measure memory pressure for GC scheduling. It runs
+    // from maxBytes down to zero.
+    mozilla::Atomic<ptrdiff_t, mozilla::ReleaseAcquire> bytes_;
+
+    // GC trigger threshold for memory allocations.
+    js::ActiveThreadData<size_t> maxBytes_;
+
+    // Whether a GC has been triggered as a result of bytes falling below
+    // zero.
+    //
+    // This should be a bool, but Atomic only supports 32-bit and pointer-sized
+    // types.
+    mozilla::Atomic<uint32_t, mozilla::ReleaseAcquire> triggered_;
+
+  public:
+    MemoryCounter()
+      : bytes_(0),
+        maxBytes_(0),
+        triggered_(false)
+    { }
+
+    void reset() {
+        bytes_ = maxBytes_;
+        triggered_ = false;
+    }
+
+    void setMax(size_t newMax) {
+        // For compatibility treat any value that exceeds PTRDIFF_T_MAX to
+        // mean that value.
+        maxBytes_ = (ptrdiff_t(newMax) >= 0) ? newMax : size_t(-1) >> 1;
+        reset();
+    }
+
+    bool update(T* owner, size_t bytes) {
+        bytes_ -= ptrdiff_t(bytes);
+        if (MOZ_UNLIKELY(isTooMuchMalloc())) {
+            if (!triggered_)
+                triggered_ = owner->triggerGCForTooMuchMalloc();
+        }
+        return triggered_;
+    }
+
+    ptrdiff_t bytes() const { return bytes_; }
+    size_t maxBytes() const { return maxBytes_; }
+    bool isTooMuchMalloc() const { return bytes_ <= 0; }
+};
+
 class GCRuntime
 {
   public:
@@ -667,8 +717,6 @@ class GCRuntime
     void setDeterministic(bool enable);
 #endif
 
-    size_t maxMallocBytesAllocated() { return maxMallocBytes; }
-
     uint64_t nextCellUniqueId() {
         MOZ_ASSERT(nextCellUniqueId_ > 0);
         uint64_t uid = ++nextCellUniqueId_;
@@ -725,12 +773,13 @@ class GCRuntime
     MOZ_MUST_USE bool addBlackRootsTracer(JSTraceDataOp traceOp, void* data);
     void removeBlackRootsTracer(JSTraceDataOp traceOp, void* data);
 
+    bool triggerGCForTooMuchMalloc() { return triggerGC(JS::gcreason::TOO_MUCH_MALLOC); }
+    int32_t getMallocBytes() const { return mallocCounter.bytes(); }
+    size_t maxMallocBytesAllocated() const { return mallocCounter.maxBytes(); }
+    bool isTooMuchMalloc() const { return mallocCounter.isTooMuchMalloc(); }
+    void resetMallocBytes() { mallocCounter.reset(); }
     void setMaxMallocBytes(size_t value);
-    int32_t getMallocBytes() const { return mallocBytesUntilGC; }
-    void resetMallocBytes();
-    bool isTooMuchMalloc() const { return mallocBytesUntilGC <= 0; }
     void updateMallocCounter(JS::Zone* zone, size_t nbytes);
-    void onTooMuchMalloc();
 
     void setGCCallback(JSGCCallback callback, void* data);
     void callGCCallback(JSGCStatus status) const;
@@ -1031,8 +1080,6 @@ class GCRuntime
 
     ActiveThreadData<RootedValueMap> rootsHash;
 
-    ActiveThreadData<size_t> maxMallocBytes;
-
     // An incrementing id used to assign unique ids to cells that require one.
     mozilla::Atomic<uint64_t, mozilla::ReleaseAcquire> nextCellUniqueId_;
 
@@ -1248,17 +1295,7 @@ class GCRuntime
     CallbackVector<JSWeakPointerZoneGroupCallback> updateWeakPointerZoneGroupCallbacks;
     CallbackVector<JSWeakPointerCompartmentCallback> updateWeakPointerCompartmentCallbacks;
 
-    /*
-     * Malloc counter to measure memory pressure for GC scheduling. It runs
-     * from maxMallocBytes down to zero.
-     */
-    mozilla::Atomic<ptrdiff_t, mozilla::ReleaseAcquire> mallocBytesUntilGC;
-
-    /*
-     * Whether a GC has been triggered as a result of mallocBytesUntilGC
-     * falling below zero.
-     */
-    mozilla::Atomic<bool, mozilla::ReleaseAcquire> mallocGCTriggered;
+    MemoryCounter<GCRuntime> mallocCounter;
 
     /*
      * The trace operations to trace embedding-specific GC roots. One is for
diff --git a/js/src/gc/Iteration.cpp b/js/src/gc/Iteration.cpp
index 228380f4740b..b83950ece6cc 100644
--- a/js/src/gc/Iteration.cpp
+++ b/js/src/gc/Iteration.cpp
@@ -20,10 +20,10 @@ using namespace js;
 using namespace js::gc;
 
 static void
-IterateCompartmentsArenasCells(JSContext* cx, Zone* zone, void* data,
-                               JSIterateCompartmentCallback compartmentCallback,
-                               IterateArenaCallback arenaCallback,
-                               IterateCellCallback cellCallback)
+IterateCompartmentsArenasCellsUnbarriered(JSContext* cx, Zone* zone, void* data,
+                                          JSIterateCompartmentCallback compartmentCallback,
+                                          IterateArenaCallback arenaCallback,
+                                          IterateCellCallback cellCallback)
 {
     for (CompartmentsInZoneIter comp(zone); !comp.done(); comp.next())
         (*compartmentCallback)(cx, data, comp);
@@ -35,40 +35,40 @@ IterateCompartmentsArenasCells(JSContext* cx, Zone* zone, void* data,
         for (ArenaIter aiter(zone, thingKind); !aiter.done(); aiter.next()) {
             Arena* arena = aiter.get();
             (*arenaCallback)(cx->runtime(), data, arena, traceKind, thingSize);
-            for (ArenaCellIter iter(arena); !iter.done(); iter.next())
+            for (ArenaCellIterUnbarriered iter(arena); !iter.done(); iter.next())
                 (*cellCallback)(cx->runtime(), data, iter.getCell(), traceKind, thingSize);
         }
     }
 }
 
 void
-js::IterateZonesCompartmentsArenasCells(JSContext* cx, void* data,
-                                        IterateZoneCallback zoneCallback,
-                                        JSIterateCompartmentCallback compartmentCallback,
-                                        IterateArenaCallback arenaCallback,
-                                        IterateCellCallback cellCallback)
+js::IterateHeapUnbarriered(JSContext* cx, void* data,
+                           IterateZoneCallback zoneCallback,
+                           JSIterateCompartmentCallback compartmentCallback,
+                           IterateArenaCallback arenaCallback,
+                           IterateCellCallback cellCallback)
 {
     AutoPrepareForTracing prop(cx, WithAtoms);
 
     for (ZonesIter zone(cx->runtime(), WithAtoms); !zone.done(); zone.next()) {
         (*zoneCallback)(cx->runtime(), data, zone);
-        IterateCompartmentsArenasCells(cx, zone, data,
-                                       compartmentCallback, arenaCallback, cellCallback);
+        IterateCompartmentsArenasCellsUnbarriered(cx, zone, data,
+                                                  compartmentCallback, arenaCallback, cellCallback);
     }
 }
 
 void
-js::IterateZoneCompartmentsArenasCells(JSContext* cx, Zone* zone, void* data,
-                                       IterateZoneCallback zoneCallback,
-                                       JSIterateCompartmentCallback compartmentCallback,
-                                       IterateArenaCallback arenaCallback,
-                                       IterateCellCallback cellCallback)
+js::IterateHeapUnbarrieredForZone(JSContext* cx, Zone* zone, void* data,
+                                  IterateZoneCallback zoneCallback,
+                                  JSIterateCompartmentCallback compartmentCallback,
+                                  IterateArenaCallback arenaCallback,
+                                  IterateCellCallback cellCallback)
 {
     AutoPrepareForTracing prop(cx, WithAtoms);
 
     (*zoneCallback)(cx->runtime(), data, zone);
-    IterateCompartmentsArenasCells(cx, zone, data,
-                                   compartmentCallback, arenaCallback, cellCallback);
+    IterateCompartmentsArenasCellsUnbarriered(cx, zone, data,
+                                              compartmentCallback, arenaCallback, cellCallback);
 }
 
 void
diff --git a/js/src/gc/Verifier.cpp b/js/src/gc/Verifier.cpp
index ff303567dfee..575e83889339 100644
--- a/js/src/gc/Verifier.cpp
+++ b/js/src/gc/Verifier.cpp
@@ -8,6 +8,7 @@
 # include <valgrind/memcheck.h>
 #endif
 
+#include "mozilla/DebugOnly.h"
 #include "mozilla/IntegerPrintfMacros.h"
 #include "mozilla/Sprintf.h"
 
@@ -302,7 +303,7 @@ CheckEdgeTracer::onChild(const JS::GCCellPtr& thing)
 void
 js::gc::AssertSafeToSkipBarrier(TenuredCell* thing)
 {
-    Zone* zone = thing->zoneFromAnyThread();
+    mozilla::DebugOnly<Zone*> zone = thing->zoneFromAnyThread();
     MOZ_ASSERT(!zone->needsIncrementalBarrier() || zone->isAtomsZone());
 }
 
@@ -531,6 +532,10 @@ CheckHeapTracer::onChild(const JS::GCCellPtr& thing)
         return;
     }
 
+    // Don't trace into GC things owned by another runtime.
+    if (cell->runtimeFromAnyThread() != rt)
+        return;
+
     WorkItem item(thing, contextName(), parentIndex);
     if (!stack.append(item))
         oom = true;
diff --git a/js/src/gc/Zone.cpp b/js/src/gc/Zone.cpp
index abbbe78f0381..f815442fd867 100644
--- a/js/src/gc/Zone.cpp
+++ b/js/src/gc/Zone.cpp
@@ -39,9 +39,6 @@ JS::Zone::Zone(JSRuntime* rt, ZoneGroup* group)
     gcWeakKeys_(group, SystemAllocPolicy(), rt->randomHashCodeScrambler()),
     gcZoneGroupEdges_(group),
     typeDescrObjects_(group, this, SystemAllocPolicy()),
-    gcMallocBytes(0),
-    gcMaxMallocBytes(0),
-    gcMallocGCTriggered(false),
     markedAtoms_(group),
     usage(&rt->gc.usage),
     threshold(),
@@ -69,6 +66,7 @@ JS::Zone::Zone(JSRuntime* rt, ZoneGroup* group)
     AutoLockGC lock(rt);
     threshold.updateAfterGC(8192, GC_NORMAL, rt->gc.tunables, rt->gc.schedulingState, lock);
     setGCMaxMallocBytes(rt->gc.maxMallocBytesAllocated() * 0.9);
+    jitCodeCounter.setMax(jit::MaxCodeBytesPerProcess * 0.8);
 }
 
 Zone::~Zone()
@@ -93,7 +91,8 @@ bool Zone::init(bool isSystemArg)
     return uniqueIds().init() &&
            gcZoneGroupEdges().init() &&
            gcWeakKeys().init() &&
-           typeDescrObjects().init();
+           typeDescrObjects().init() &&
+           markedAtoms().init();
 }
 
 void
@@ -110,33 +109,6 @@ Zone::setNeedsIncrementalBarrier(bool needs, ShouldUpdateJit updateJit)
     needsIncrementalBarrier_ = needs;
 }
 
-void
-Zone::resetGCMallocBytes()
-{
-    gcMallocBytes = ptrdiff_t(gcMaxMallocBytes);
-    gcMallocGCTriggered = false;
-}
-
-void
-Zone::setGCMaxMallocBytes(size_t value)
-{
-    /*
-     * For compatibility treat any value that exceeds PTRDIFF_T_MAX to
-     * mean that value.
-     */
-    gcMaxMallocBytes = (ptrdiff_t(value) >= 0) ? value : size_t(-1) >> 1;
-    resetGCMallocBytes();
-}
-
-void
-Zone::onTooMuchMalloc()
-{
-    if (!gcMallocGCTriggered) {
-        GCRuntime& gc = runtimeFromAnyThread()->gc;
-        gcMallocGCTriggered = gc.triggerZoneGC(this, JS::gcreason::TOO_MUCH_MALLOC);
-    }
-}
-
 void
 Zone::beginSweepTypes(FreeOp* fop, bool releaseTypes)
 {
diff --git a/js/src/gc/Zone.h b/js/src/gc/Zone.h
index 9bd09c1e0f57..15f234a00d5c 100644
--- a/js/src/gc/Zone.h
+++ b/js/src/gc/Zone.h
@@ -166,16 +166,6 @@ struct Zone : public JS::shadow::Zone,
                                 size_t* shapeTables,
                                 size_t* atomsMarkBitmaps);
 
-    void resetGCMallocBytes();
-    void setGCMaxMallocBytes(size_t value);
-    void updateMallocCounter(size_t nbytes) {
-        // Note: this code may be run from worker threads. We tolerate any
-        // thread races when updating gcMallocBytes.
-        gcMallocBytes -= ptrdiff_t(nbytes);
-        if (MOZ_UNLIKELY(isTooMuchMalloc()))
-            onTooMuchMalloc();
-    }
-
     // Iterate over all cells in the zone. See the definition of ZoneCellIter
     // in jsgcinlines.h for the possible arguments and documentation.
     template <typename T, typename... Args>
@@ -183,11 +173,8 @@ struct Zone : public JS::shadow::Zone,
         return js::gc::ZoneCellIter<T>(const_cast<Zone*>(this), mozilla::Forward<Args>(args)...);
     }
 
-    bool isTooMuchMalloc() const { return gcMallocBytes <= 0; }
-    void onTooMuchMalloc();
-
     MOZ_MUST_USE void* onOutOfMemory(js::AllocFunction allocFunc, size_t nbytes,
-                                               void* reallocPtr = nullptr) {
+                                     void* reallocPtr = nullptr) {
         if (!js::CurrentThreadCanAccessRuntime(runtime_))
             return nullptr;
         return runtimeFromActiveCooperatingThread()->onOutOfMemory(allocFunc, nbytes, reallocPtr);
@@ -399,31 +386,48 @@ struct Zone : public JS::shadow::Zone,
                                              js::SystemAllocPolicy>;
   private:
     js::ZoneGroupData<JS::WeakCache<TypeDescrObjectSet>> typeDescrObjects_;
+
+    // Malloc counter to measure memory pressure for GC scheduling. This
+    // counter should be used only when it's not possible to know the size of
+    // a free.
+    js::gc::MemoryCounter<Zone> gcMallocCounter;
+
+    // Counter of JIT code executable memory for GC scheduling. Also imprecise,
+    // since wasm can generate code that outlives a zone.
+    js::gc::MemoryCounter<Zone> jitCodeCounter;
+
   public:
     JS::WeakCache<TypeDescrObjectSet>& typeDescrObjects() { return typeDescrObjects_.ref(); }
 
     bool addTypeDescrObject(JSContext* cx, HandleObject obj);
 
-    // Malloc counter to measure memory pressure for GC scheduling. It runs from
-    // gcMaxMallocBytes down to zero. This counter should be used only when it's
-    // not possible to know the size of a free.
-    mozilla::Atomic<ptrdiff_t, mozilla::ReleaseAcquire> gcMallocBytes;
+    bool triggerGCForTooMuchMalloc() {
+        return runtimeFromAnyThread()->gc.triggerZoneGC(this, JS::gcreason::TOO_MUCH_MALLOC);
+    }
 
-    // GC trigger threshold for allocations on the C heap.
-    js::ActiveThreadData<size_t> gcMaxMallocBytes;
+    void resetGCMallocBytes() { gcMallocCounter.reset(); }
+    void setGCMaxMallocBytes(size_t value) { gcMallocCounter.setMax(value); }
+    void updateMallocCounter(size_t nbytes) { gcMallocCounter.update(this, nbytes); }
+    size_t GCMaxMallocBytes() const { return gcMallocCounter.maxBytes(); }
+    size_t GCMallocBytes() const { return gcMallocCounter.bytes(); }
 
-    // Whether a GC has been triggered as a result of gcMallocBytes falling
-    // below zero.
-    //
-    // This should be a bool, but Atomic only supports 32-bit and pointer-sized
-    // types.
-    mozilla::Atomic<uint32_t, mozilla::ReleaseAcquire> gcMallocGCTriggered;
+    void updateJitCodeMallocBytes(size_t size) { jitCodeCounter.update(this, size); }
+
+    // Resets all the memory counters.
+    void resetAllMallocBytes() {
+        resetGCMallocBytes();
+        jitCodeCounter.reset();
+    }
+    bool isTooMuchMalloc() const {
+        return gcMallocCounter.isTooMuchMalloc() ||
+               jitCodeCounter.isTooMuchMalloc();
+    }
 
   private:
     // Bitmap of atoms marked by this zone.
-    js::ZoneGroupOrGCTaskData<js::gc::AtomMarkingRuntime::Bitmap> markedAtoms_;
+    js::ZoneGroupOrGCTaskData<js::SparseBitmap> markedAtoms_;
   public:
-    js::gc::AtomMarkingRuntime::Bitmap& markedAtoms() { return markedAtoms_.ref(); }
+    js::SparseBitmap& markedAtoms() { return markedAtoms_.ref(); }
 
     // Track heap usage under this Zone.
     js::gc::HeapUsage usage;
diff --git a/js/src/gdb/tests/test-ExecutableAllocator.cpp b/js/src/gdb/tests/test-ExecutableAllocator.cpp
index 7cb7ad364ca4..c9636312a47c 100644
--- a/js/src/gdb/tests/test-ExecutableAllocator.cpp
+++ b/js/src/gdb/tests/test-ExecutableAllocator.cpp
@@ -18,7 +18,7 @@ FRAGMENT(ExecutableAllocator, onepool) {
     using namespace js::jit;
     ExecutablePool* pool = nullptr;
     ExecutableAllocator execAlloc(cx->runtime());
-    execAlloc.alloc(16 * 1024, &pool, BASELINE_CODE);
+    execAlloc.alloc(cx, 16 * 1024, &pool, BASELINE_CODE);
 
     breakpoint();
 
@@ -32,10 +32,10 @@ FRAGMENT(ExecutableAllocator, twopools) {
     ExecutablePool* pool = nullptr;
     ExecutableAllocator execAlloc(cx->runtime());
 
-    execAlloc.alloc(16 * 1024, &init, BASELINE_CODE);
+    execAlloc.alloc(cx, 16 * 1024, &init, BASELINE_CODE);
 
     do { // Keep allocating until we get a second pool.
-        execAlloc.alloc(32 * 1024, &pool, ION_CODE);
+        execAlloc.alloc(cx, 32 * 1024, &pool, ION_CODE);
     } while (pool == init);
 
     breakpoint();
diff --git a/js/src/jit-test/lib/wasm-binary.js b/js/src/jit-test/lib/wasm-binary.js
index e57ac84914c3..df5116b35588 100644
--- a/js/src/jit-test/lib/wasm-binary.js
+++ b/js/src/jit-test/lib/wasm-binary.js
@@ -71,6 +71,7 @@ const I32ConstCode     = 0x41;
 const I64ConstCode     = 0x42;
 const F32ConstCode     = 0x43;
 const F64ConstCode     = 0x44;
+const I32AddCode       = 0x6a;
 const I32DivSCode      = 0x6d;
 const I32DivUCode      = 0x6e;
 const I32RemSCode      = 0x6f;
diff --git a/js/src/jit-test/modules/empty.js b/js/src/jit-test/modules/empty.js
new file mode 100644
index 000000000000..bd9ec079d80d
--- /dev/null
+++ b/js/src/jit-test/modules/empty.js
@@ -0,0 +1 @@
+// Intentionally empty.
diff --git a/js/src/jit-test/modules/export-circular-nonexisting-binding-1.js b/js/src/jit-test/modules/export-circular-nonexisting-binding-1.js
new file mode 100644
index 000000000000..2b91b6a28473
--- /dev/null
+++ b/js/src/jit-test/modules/export-circular-nonexisting-binding-1.js
@@ -0,0 +1,4 @@
+import "export-circular-nonexisting-binding-2.js";
+
+export* from "empty.js";
+export {x} from "empty.js";
diff --git a/js/src/jit-test/modules/export-circular-nonexisting-binding-2.js b/js/src/jit-test/modules/export-circular-nonexisting-binding-2.js
new file mode 100644
index 000000000000..ba7dcc1b4879
--- /dev/null
+++ b/js/src/jit-test/modules/export-circular-nonexisting-binding-2.js
@@ -0,0 +1 @@
+export {x} from "export-circular-nonexisting-binding-1.js";
diff --git a/js/src/jit-test/modules/export-star-circular-1.js b/js/src/jit-test/modules/export-star-circular-1.js
new file mode 100644
index 000000000000..9a0771b02411
--- /dev/null
+++ b/js/src/jit-test/modules/export-star-circular-1.js
@@ -0,0 +1 @@
+export* from "export-star-circular-2.js";
diff --git a/js/src/jit-test/modules/export-star-circular-2.js b/js/src/jit-test/modules/export-star-circular-2.js
new file mode 100644
index 000000000000..b273d9cefa77
--- /dev/null
+++ b/js/src/jit-test/modules/export-star-circular-2.js
@@ -0,0 +1,3 @@
+export {y as x} from "export-star-circular-1.js";
+
+export var y = "pass";
diff --git a/js/src/jit-test/tests/atomics/basic-tests.js b/js/src/jit-test/tests/atomics/basic-tests.js
index 3869d5dd6a7d..59f7e5ac3008 100644
--- a/js/src/jit-test/tests/atomics/basic-tests.js
+++ b/js/src/jit-test/tests/atomics/basic-tests.js
@@ -212,8 +212,10 @@ function testRangeCAS(a) {
     assertErrorMessage(() => Atomics.compareExchange(a, -1, 0, 1), RangeError, msg);
     assertEq(a[0], 0);
 
-    assertErrorMessage(() => Atomics.compareExchange(a, "hi", 0, 1), RangeError, msg);
-    assertEq(a[0], 0);
+    // Converted to 0
+    assertEq(Atomics.compareExchange(a, "hi", 0, 33), 0);
+    assertEq(a[0], 33);
+    a[0] = 0;
 
     assertErrorMessage(() => Atomics.compareExchange(a, a.length + 5, 0, 1), RangeError, msg);
     assertEq(a[0], 0);
diff --git a/js/src/jit-test/tests/cacheir/nukedCCW.js b/js/src/jit-test/tests/cacheir/nukedCCW.js
new file mode 100644
index 000000000000..303750ce482a
--- /dev/null
+++ b/js/src/jit-test/tests/cacheir/nukedCCW.js
@@ -0,0 +1,23 @@
+var wrapper = evaluate("({a: 15, b: {c: 42}})", {global: newGlobal({sameZoneAs: this})});
+
+function test() {
+    var i, error;
+    try {
+        for (i = 0; i < 150; i++) {
+            assertEq(wrapper.b.c, 42);
+            assertEq(wrapper.a, 15);
+
+            if (i == 142) {
+                // Next access to wrapper.b should throw.
+                nukeCCW(wrapper);
+            }
+        }
+    } catch (e) {
+        error = e;
+    }
+
+    assertEq(error.message.includes("dead object"), true);
+    assertEq(i, 143);
+}
+
+test();
diff --git a/js/src/jit-test/tests/gc/bug-1337414.js b/js/src/jit-test/tests/gc/bug-1337414.js
new file mode 100644
index 000000000000..9e647a810cc2
--- /dev/null
+++ b/js/src/jit-test/tests/gc/bug-1337414.js
@@ -0,0 +1,46 @@
+var lfLogBuffer = `
+gczeal(15,10);
+try {
+    a = []
+    gczeal(2, 2)()
+} catch (e) {}
+a.every(function() {})
+//corefuzz-dcd-endofdata
+//corefuzz-dcd-selectmode 5
+`;
+lfLogBuffer = lfLogBuffer.split('\n');
+lfPreamble = `
+`;
+var lfCodeBuffer = "";
+var lfRunTypeLimit = 7;
+var lfOffThreadGlobal = newGlobal();
+try {} catch (lfVare5) {}
+var lfAccumulatedCode = lfPreamble;
+while (true) {
+    var line = lfLogBuffer.shift();
+    if (line == null) {
+        break;
+    } else if (line == "//corefuzz-dcd-endofdata") {
+        loadFile(lfCodeBuffer);
+    } else if (line.indexOf("//corefuzz-dcd-selectmode ") === 0) {
+        loadFile(line);
+    } else {
+        lfCodeBuffer += line + "\n";
+    }
+}
+if (lfCodeBuffer) loadFile(lfCodeBuffer);
+function loadFile(lfVarx) {
+    try {
+        if (lfVarx.indexOf("//corefuzz-dcd-selectmode ") === 0) {
+            lfRunTypeId = parseInt(lfVarx.split(" ")[1]) % lfRunTypeLimit;
+        } else {
+            switch (lfRunTypeId) {
+                case 5:
+                    evalInWorker(lfAccumulatedCode);
+                    evaluate(lfVarx);
+            }
+        }
+    } catch (lfVare) {
+        lfAccumulatedCode += "try { evaluate(`\n" + lfVarx + "\n`); } catch(exc) {}\n";
+    }
+}
diff --git a/js/src/jit-test/tests/modules/export-circular-nonexisting-binding.js b/js/src/jit-test/tests/modules/export-circular-nonexisting-binding.js
new file mode 100644
index 000000000000..387c7c369a3d
--- /dev/null
+++ b/js/src/jit-test/tests/modules/export-circular-nonexisting-binding.js
@@ -0,0 +1,3 @@
+// |jit-test| module; error:SyntaxError
+
+import "export-circular-nonexisting-binding-1.js";
diff --git a/js/src/jit-test/tests/modules/export-star-cannot-rescue-missing-export.js b/js/src/jit-test/tests/modules/export-star-cannot-rescue-missing-export.js
new file mode 100644
index 000000000000..f87829d89b8b
--- /dev/null
+++ b/js/src/jit-test/tests/modules/export-star-cannot-rescue-missing-export.js
@@ -0,0 +1,4 @@
+// |jit-test| module; error:SyntaxError
+
+export { a } from "empty.js";
+export* from "module1.js";
diff --git a/js/src/jit-test/tests/modules/export-star-circular-dependencies.js b/js/src/jit-test/tests/modules/export-star-circular-dependencies.js
new file mode 100644
index 000000000000..9aa612f087db
--- /dev/null
+++ b/js/src/jit-test/tests/modules/export-star-circular-dependencies.js
@@ -0,0 +1,6 @@
+// |jit-test| module
+
+import { x, y } from "export-star-circular-1.js";
+
+assertEq(x, "pass");
+assertEq(y, "pass");
diff --git a/js/src/jit-test/tests/wasm/binary.js b/js/src/jit-test/tests/wasm/binary.js
index f903f1c9fd8c..3aa6d69bef5e 100644
--- a/js/src/jit-test/tests/wasm/binary.js
+++ b/js/src/jit-test/tests/wasm/binary.js
@@ -64,9 +64,6 @@ assertErrorMessage(() => wasmEval(toU8([magic0, magic1, magic2, magic3, 1])), Co
 assertErrorMessage(() => wasmEval(toU8([magic0, magic1, magic2, magic3, ver0])), CompileError, versionError(0x6d736100));
 assertErrorMessage(() => wasmEval(toU8([magic0, magic1, magic2, magic3, ver0, ver1, ver2])), CompileError, versionError(0x6d736100));
 
-// This test should be removed shortly.
-assertEq(WebAssembly.validate(toU8([magic0, magic1, magic2, magic3, 0xd, 0x0, 0x0, 0x0])), true);
-
 function moduleHeaderThen(...rest) {
     return [magic0, magic1, magic2, magic3, ver0, ver1, ver2, ver3, ...rest];
 }
diff --git a/js/src/jit-test/tests/wasm/errors.js b/js/src/jit-test/tests/wasm/errors.js
index 65eb1cc20521..3efcf838bdb9 100644
--- a/js/src/jit-test/tests/wasm/errors.js
+++ b/js/src/jit-test/tests/wasm/errors.js
@@ -3,6 +3,7 @@ load(libdir + "wasm-binary.js");
 
 const Module = WebAssembly.Module;
 const Instance = WebAssembly.Instance;
+const CompileError = WebAssembly.CompileError;
 const RuntimeError = WebAssembly.RuntimeError;
 
 function isWasmFunction(name) {
@@ -153,3 +154,21 @@ for (var i = 1; i < N; i++) {
     assertEq(binary[stack[i].line], i == 3 ? CallIndirectCode : CallCode);
     assertEq(stack[i].column, 1);
 }
+
+function testCompileError(opcode, text) {
+    var binary = new Uint8Array(wasmTextToBinary(text));
+    var exn;
+    try {
+        new Instance(new Module(binary));
+    } catch (e) {
+        exn = e;
+    }
+
+    assertEq(exn instanceof CompileError, true);
+    var offset = Number(exn.message.match(/at offset (\d*)/)[1]);
+    assertEq(binary[offset], opcode);
+}
+
+testCompileError(CallCode, '(module (func $f (param i32)) (func $g call $f))');
+testCompileError(I32AddCode, '(module (func (i32.add (i32.const 1) (f32.const 1))))');
+testCompileError(EndCode, '(module (func (block i32)))');
diff --git a/js/src/jit-test/tests/wasm/regress/current-memory-tls.js b/js/src/jit-test/tests/wasm/regress/current-memory-tls.js
new file mode 100644
index 000000000000..b252d1ef3080
--- /dev/null
+++ b/js/src/jit-test/tests/wasm/regress/current-memory-tls.js
@@ -0,0 +1,97 @@
+load(libdir + "wasm.js");
+
+// Bug 1341650:
+// - when compiled with Ion, pass the TLS register to current_memory;
+// - when compiled with Baseline, don't clobber the last stack slot when
+// calling into current_memory/grow_memory;
+
+// This toy module starts with an empty memory, then tries to set values at different
+// indexes, automatically growing memory when that would trigger an out of
+// bounds access, for the exact right amount of pages. Note it's not made for
+// efficiency, but optimizing it doesn't trigger the bugs mentioned above.
+
+let i = new WebAssembly.Instance(new WebAssembly.Module(wasmTextToBinary(`
+(module
+    (memory $mem (export "mem") 0 65535)
+
+    (func (export "cur_mem") (result i32) (current_memory))
+
+    (func $maybeGrow (param $i i32) (local $smem i32)
+     ;; get current_memory in number of bytes, not pages.
+     current_memory
+     i64.extend_u/i32
+     i64.const 65536
+     i64.mul
+
+     ;; get the last byte index accessed by an int32 access.
+     get_local $i
+     i32.const 3
+     i32.add
+     tee_local $i
+     i64.extend_u/i32
+
+     ;; if the memory is too small, grow it.
+     i64.le_u
+     if
+         ;; get the floor of the accessed *page* index.
+         get_local $i
+         i64.extend_u/i32
+         i64.const 65536
+         i64.div_u
+
+         ;; subtract to that the size of the current memory in pages;
+         ;; that's the amount of pages we want to grow, minus one.
+         current_memory
+         i64.extend_u/i32
+
+         i64.sub
+
+         ;; add 1 to that amount.
+         i64.const 1
+         i64.add
+
+         ;; get back to i32 and grow memory.
+         i32.wrap/i64
+         grow_memory
+         drop
+     end
+    )
+
+    (func (export "set") (param $i i32) (param $v i32)
+     get_local $i
+     call $maybeGrow
+     get_local $i
+     get_local $v
+     i32.store
+    )
+
+    (func (export "get") (param $i i32) (result i32)
+     get_local $i
+     i32.load
+    )
+)
+`))).exports;
+
+assertEq(i.cur_mem(), 0);
+
+i.set(0, 1);
+assertEq(i.get(0), 1);
+
+assertEq(i.cur_mem(), 1);
+
+i.set(1234, 1);
+assertEq(i.get(1234), 1);
+
+assertEq(i.cur_mem(), 1);
+
+i.set(65532, 1);
+assertEq(i.get(65532), 1);
+
+assertErrorMessage(() => i.get(65533), WebAssembly.RuntimeError, /index out of bounds/);
+
+assertEq(i.cur_mem(), 1);
+
+i.set(65533, 1);
+assertEq(i.get(65533), 1);
+
+assertEq(i.cur_mem(), 2);
diff --git a/js/src/jit-test/tests/wasm/spec/binary.wast b/js/src/jit-test/tests/wasm/spec/binary.wast
index b0ab9c4266fd..9bb55ef9ea45 100644
--- a/js/src/jit-test/tests/wasm/spec/binary.wast
+++ b/js/src/jit-test/tests/wasm/spec/binary.wast
@@ -1,18 +1,18 @@
-(module "\00asm\0d\00\00\00")
-(module "\00asm" "\0d\00\00\00")
-(module $M1 "\00asm\0d\00\00\00")
-(module $M2 "\00asm" "\0d\00\00\00")
+(module "\00asm\01\00\00\00")
+(module "\00asm" "\01\00\00\00")
+(module $M1 "\00asm\01\00\00\00")
+(module $M2 "\00asm" "\01\00\00\00")
 
 (assert_malformed (module "") "unexpected end")
 (assert_malformed (module "\01") "unexpected end")
 (assert_malformed (module "\00as") "unexpected end")
 (assert_malformed (module "asm\00") "magic header not detected")
 (assert_malformed (module "msa\00") "magic header not detected")
-(assert_malformed (module "msa\00\0d\00\00\00") "magic header not detected")
+(assert_malformed (module "msa\00\01\00\00\00") "magic header not detected")
 (assert_malformed (module "msa\00\00\00\00\0d") "magic header not detected")
 
 (assert_malformed (module "\00asm") "unexpected end")
-(assert_malformed (module "\00asm\0d") "unexpected end")
-(assert_malformed (module "\00asm\0d\00\00") "unexpected end")
+(assert_malformed (module "\00asm\01") "unexpected end")
+(assert_malformed (module "\00asm\01\00\00") "unexpected end")
 (assert_malformed (module "\00asm\0e\00\00\00") "unknown binary version")
 (assert_malformed (module "\00asm\00\00\00\0d") "unknown binary version")
diff --git a/js/src/jit-test/tests/wasm/spec/custom_section.wast b/js/src/jit-test/tests/wasm/spec/custom_section.wast
index 66e707c8fc36..f087a9d2d9c3 100644
--- a/js/src/jit-test/tests/wasm/spec/custom_section.wast
+++ b/js/src/jit-test/tests/wasm/spec/custom_section.wast
@@ -1,5 +1,5 @@
 (module
-  "\00asm" "\0d\00\00\00"
+  "\00asm" "\01\00\00\00"
   "\00\24\10" "a custom section" "this is the payload"
   "\00\20\10" "a custom section" "this is payload"
   "\00\11\10" "a custom section" ""
@@ -9,7 +9,7 @@
 )
 
 (module
-  "\00asm" "\0d\00\00\00"
+  "\00asm" "\01\00\00\00"
   "\00\0e\06" "custom" "payload"
   "\00\0e\06" "custom" "payload"
   "\01\01\00"  ;; type section
@@ -45,7 +45,7 @@
 )
 
 (module
-  "\00asm" "\0d\00\00\00"
+  "\00asm" "\01\00\00\00"
   "\01\07\01\60\02\7f\7f\01\7f"                ;; type section
   "\00\1a\06" "custom" "this is the payload"   ;; custom section
   "\03\02\01\00"                               ;; function section
@@ -56,7 +56,7 @@
 
 (assert_malformed
   (module
-    "\00asm" "\0d\00\00\00"
+    "\00asm" "\01\00\00\00"
     "\00\00"
   )
   "unexpected end"
@@ -64,7 +64,7 @@
 
 (assert_malformed
   (module
-    "\00asm" "\0d\00\00\00"
+    "\00asm" "\01\00\00\00"
     "\00\26\10" "a custom section" "this is the payload"
   )
   "unexpected end"
@@ -72,7 +72,7 @@
 
 (assert_malformed
   (module
-    "\00asm" "\0d\00\00\00"
+    "\00asm" "\01\00\00\00"
     "\00\25\10" "a custom section" "this is the payload"
     "\00\24\10" "a custom section" "this is the payload"
   )
@@ -81,7 +81,7 @@
 
 (assert_malformed
   (module
-    "\00asm" "\0d\00\00\00"
+    "\00asm" "\01\00\00\00"
     "\01\07\01\60\02\7f\7f\01\7f"                         ;; type section
     "\00\25\10" "a custom section" "this is the payload"  ;; invalid length!
     "\03\02\01\00"                                        ;; function section
diff --git a/js/src/jit/ExecutableAllocator.cpp b/js/src/jit/ExecutableAllocator.cpp
index 808c87a9bde0..e53c5fcfef29 100644
--- a/js/src/jit/ExecutableAllocator.cpp
+++ b/js/src/jit/ExecutableAllocator.cpp
@@ -238,7 +238,7 @@ ExecutableAllocator::createPool(size_t n)
 }
 
 void*
-ExecutableAllocator::alloc(size_t n, ExecutablePool** poolp, CodeKind type)
+ExecutableAllocator::alloc(JSContext* cx, size_t n, ExecutablePool** poolp, CodeKind type)
 {
     // Don't race with reprotectAll called from the signal handler.
     JitRuntime::AutoPreventBackedgePatching apbp(rt_);
@@ -261,6 +261,9 @@ ExecutableAllocator::alloc(size_t n, ExecutablePool** poolp, CodeKind type)
     // (found, or created if necessary) a pool that had enough space.
     void* result = (*poolp)->alloc(n, type);
     MOZ_ASSERT(result);
+
+    cx->zone()->updateJitCodeMallocBytes(n);
+
     return result;
 }
 
diff --git a/js/src/jit/ExecutableAllocator.h b/js/src/jit/ExecutableAllocator.h
index c6e90e8fb561..3a42918142ef 100644
--- a/js/src/jit/ExecutableAllocator.h
+++ b/js/src/jit/ExecutableAllocator.h
@@ -177,7 +177,7 @@ class ExecutableAllocator
     // alloc() returns a pointer to some memory, and also (by reference) a
     // pointer to reference-counted pool. The caller owns a reference to the
     // pool; i.e. alloc() increments the count before returning the object.
-    void* alloc(size_t n, ExecutablePool** poolp, CodeKind type);
+    void* alloc(JSContext* cx, size_t n, ExecutablePool** poolp, CodeKind type);
 
     void releasePoolPages(ExecutablePool* pool);
 
diff --git a/js/src/jit/IonAnalysis.cpp b/js/src/jit/IonAnalysis.cpp
index 9260df3114a3..5410c7a4b657 100644
--- a/js/src/jit/IonAnalysis.cpp
+++ b/js/src/jit/IonAnalysis.cpp
@@ -3038,12 +3038,6 @@ jit::AssertExtendedGraphCoherency(MIRGraph& graph, bool underValueNumberer, bool
         for (MPhiIterator iter(block->phisBegin()), end(block->phisEnd()); iter != end; ++iter) {
             MPhi* phi = *iter;
             for (size_t i = 0, e = phi->numOperands(); i < e; ++i) {
-                // We sometimes see a phi with a magic-optimized-arguments
-                // operand defined in the normal entry block, while the phi is
-                // also reachable from the OSR entry (auto-regress/bug779818.js)
-                if (phi->getOperand(i)->type() == MIRType::MagicOptimizedArguments)
-                    continue;
-
                 MOZ_ASSERT(phi->getOperand(i)->block()->dominates(block->getPredecessor(i)),
                            "Phi input is not dominated by its operand");
             }
diff --git a/js/src/jit/Linker.cpp b/js/src/jit/Linker.cpp
index 674f7a5b5fff..6038687f7d47 100644
--- a/js/src/jit/Linker.cpp
+++ b/js/src/jit/Linker.cpp
@@ -31,9 +31,10 @@ Linker::newCode(JSContext* cx, CodeKind kind, bool hasPatchableBackedges /* = fa
     bytesNeeded = AlignBytes(bytesNeeded, sizeof(void*));
 
     ExecutableAllocator& execAlloc = hasPatchableBackedges
-        ? cx->runtime()->jitRuntime()->backedgeExecAlloc()
-        : cx->runtime()->jitRuntime()->execAlloc();
-    uint8_t* result = (uint8_t*)execAlloc.alloc(bytesNeeded, &pool, kind);
+                                     ? cx->runtime()->jitRuntime()->backedgeExecAlloc()
+                                     : cx->runtime()->jitRuntime()->execAlloc();
+
+    uint8_t* result = (uint8_t*)execAlloc.alloc(cx, bytesNeeded, &pool, kind);
     if (!result)
         return fail(cx);
 
diff --git a/js/src/jit/MacroAssembler.cpp b/js/src/jit/MacroAssembler.cpp
index b0ad34e14e24..58c801af07a6 100644
--- a/js/src/jit/MacroAssembler.cpp
+++ b/js/src/jit/MacroAssembler.cpp
@@ -2807,7 +2807,7 @@ MacroAssembler::wasmCallBuiltinInstanceMethod(const ABIArg& instanceArg,
     if (instanceArg.kind() == ABIArg::GPR) {
         loadPtr(Address(WasmTlsReg, offsetof(wasm::TlsData, instance)), instanceArg.gpr());
     } else if (instanceArg.kind() == ABIArg::Stack) {
-        // Safe to use ABINonArgReg0 since its the last thing before the call
+        // Safe to use ABINonArgReg0 since it's the last thing before the call.
         Register scratch = ABINonArgReg0;
         loadPtr(Address(WasmTlsReg, offsetof(wasm::TlsData, instance)), scratch);
         storePtr(scratch, Address(getStackPointer(), instanceArg.offsetFromArgBase()));
diff --git a/js/src/jit/ProcessExecutableMemory.cpp b/js/src/jit/ProcessExecutableMemory.cpp
index 9a66b042c2f9..d43f2e5915a9 100644
--- a/js/src/jit/ProcessExecutableMemory.cpp
+++ b/js/src/jit/ProcessExecutableMemory.cpp
@@ -405,14 +405,6 @@ class PageBitSet
 #endif
 };
 
-// Limit on the number of bytes of executable memory to prevent JIT spraying
-// attacks.
-#if JS_BITS_PER_WORD == 32
-static const size_t MaxCodeBytesPerProcess = 128 * 1024 * 1024;
-#else
-static const size_t MaxCodeBytesPerProcess = 640 * 1024 * 1024;
-#endif
-
 // Per-process executable memory allocator. It reserves a block of memory of
 // MaxCodeBytesPerProcess bytes, then allocates/deallocates pages from that.
 //
diff --git a/js/src/jit/ProcessExecutableMemory.h b/js/src/jit/ProcessExecutableMemory.h
index 078ce7cb75fc..3323c5cba4f5 100644
--- a/js/src/jit/ProcessExecutableMemory.h
+++ b/js/src/jit/ProcessExecutableMemory.h
@@ -12,6 +12,14 @@
 namespace js {
 namespace jit {
 
+// Limit on the number of bytes of executable memory to prevent JIT spraying
+// attacks.
+#if JS_BITS_PER_WORD == 32
+static const size_t MaxCodeBytesPerProcess = 128 * 1024 * 1024;
+#else
+static const size_t MaxCodeBytesPerProcess = 1 * 1024 * 1024 * 1024;
+#endif
+
 // Executable code is allocated in 64K chunks. ExecutableAllocator uses pools
 // that are at least this big. Code we allocate does not necessarily have 64K
 // alignment though.
diff --git a/js/src/jsfriendapi.cpp b/js/src/jsfriendapi.cpp
index a134febf6a39..0989b942fb39 100644
--- a/js/src/jsfriendapi.cpp
+++ b/js/src/jsfriendapi.cpp
@@ -1184,11 +1184,11 @@ js::DumpHeap(JSContext* cx, FILE* fp, js::DumpHeapNurseryBehaviour nurseryBehavi
     fprintf(dtrc.output, "==========\n");
 
     dtrc.prefix = "> ";
-    IterateZonesCompartmentsArenasCells(cx, &dtrc,
-                                        DumpHeapVisitZone,
-                                        DumpHeapVisitCompartment,
-                                        DumpHeapVisitArena,
-                                        DumpHeapVisitCell);
+    IterateHeapUnbarriered(cx, &dtrc,
+                                                   DumpHeapVisitZone,
+                                                   DumpHeapVisitCompartment,
+                                                   DumpHeapVisitArena,
+                                                   DumpHeapVisitCell);
 
     fflush(dtrc.output);
 }
diff --git a/js/src/jsfriendapi.h b/js/src/jsfriendapi.h
index fdcc1400782f..2460e31f8349 100644
--- a/js/src/jsfriendapi.h
+++ b/js/src/jsfriendapi.h
@@ -1130,12 +1130,17 @@ class RegExpGuard;
 extern JS_FRIEND_API(bool)
 RegExpToSharedNonInline(JSContext* cx, JS::HandleObject regexp, RegExpGuard* shared);
 
-/* Implemented in jswrapper.cpp. */
+/* Implemented in CrossCompartmentWrapper.cpp. */
 typedef enum NukeReferencesToWindow {
     NukeWindowReferences,
     DontNukeWindowReferences
 } NukeReferencesToWindow;
 
+typedef enum NukeReferencesFromTarget {
+    NukeAllReferences,
+    NukeIncomingReferences,
+} NukeReferencesFromTarget;
+
 /*
  * These filters are designed to be ephemeral stack classes, and thus don't
  * do any rooting or holding of their members.
@@ -1178,7 +1183,8 @@ extern JS_FRIEND_API(bool)
 NukeCrossCompartmentWrappers(JSContext* cx,
                              const CompartmentFilter& sourceFilter,
                              const CompartmentFilter& targetFilter,
-                             NukeReferencesToWindow nukeReferencesToWindow);
+                             NukeReferencesToWindow nukeReferencesToWindow,
+                             NukeReferencesFromTarget nukeReferencesFromTarget);
 
 /* Specify information about DOMProxy proxies in the DOM, for use by ICs. */
 
diff --git a/js/src/jsgc.cpp b/js/src/jsgc.cpp
index 48fb02e2f72d..c1121371edd1 100644
--- a/js/src/jsgc.cpp
+++ b/js/src/jsgc.cpp
@@ -816,7 +816,6 @@ GCRuntime::GCRuntime(JSRuntime* rt) :
     marker(rt),
     usage(nullptr),
     mMemProfiler(rt),
-    maxMallocBytes(0),
     nextCellUniqueId_(LargestTaggedNullCellPointer + 1), // Ensure disjoint from null tagged pointers.
     numArenasFreeCommitted(0),
     verifyPreData(nullptr),
@@ -864,8 +863,6 @@ GCRuntime::GCRuntime(JSRuntime* rt) :
     incrementalLimit(0),
 #endif
     fullCompartmentChecks(false),
-    mallocBytesUntilGC(0),
-    mallocGCTriggered(false),
     alwaysPreserveCode(false),
 #ifdef DEBUG
     arenasEmptyAtShutdown(true),
@@ -1259,7 +1256,7 @@ GCRuntime::getParameter(JSGCParamKey key, const AutoLockGC& lock)
       case JSGC_MAX_BYTES:
         return uint32_t(tunables.gcMaxBytes());
       case JSGC_MAX_MALLOC_BYTES:
-        return maxMallocBytes;
+        return mallocCounter.maxBytes();
       case JSGC_BYTES:
         return uint32_t(usage.gcBytes());
       case JSGC_MODE:
@@ -1539,40 +1536,19 @@ js::RemoveRawValueRoot(JSContext* cx, Value* vp)
 void
 GCRuntime::setMaxMallocBytes(size_t value)
 {
-    /*
-     * For compatibility treat any value that exceeds PTRDIFF_T_MAX to
-     * mean that value.
-     */
-    maxMallocBytes = (ptrdiff_t(value) >= 0) ? value : size_t(-1) >> 1;
-    resetMallocBytes();
+    mallocCounter.setMax(value);
     for (ZonesIter zone(rt, WithAtoms); !zone.done(); zone.next())
         zone->setGCMaxMallocBytes(value);
 }
 
-void
-GCRuntime::resetMallocBytes()
-{
-    mallocBytesUntilGC = ptrdiff_t(maxMallocBytes);
-    mallocGCTriggered = false;
-}
-
 void
 GCRuntime::updateMallocCounter(JS::Zone* zone, size_t nbytes)
 {
-    mallocBytesUntilGC -= ptrdiff_t(nbytes);
-    if (MOZ_UNLIKELY(isTooMuchMalloc()))
-        onTooMuchMalloc();
-    else if (zone)
+    bool triggered = mallocCounter.update(this, nbytes);
+    if (!triggered && zone)
         zone->updateMallocCounter(nbytes);
 }
 
-void
-GCRuntime::onTooMuchMalloc()
-{
-    if (!mallocGCTriggered)
-        mallocGCTriggered = triggerGC(JS::gcreason::TOO_MUCH_MALLOC);
-}
-
 double
 ZoneHeapThreshold::allocTrigger(bool highFrequencyGC) const
 {
@@ -4186,7 +4162,7 @@ js::gc::MarkingValidator::nonIncrementalMark(AutoLockForExclusiveAccess& lock)
     /* Save existing mark bits. */
     for (auto chunk = gc->allNonEmptyChunks(); !chunk.done(); chunk.next()) {
         ChunkBitmap* bitmap = &chunk->bitmap;
-	ChunkBitmap* entry = js_new<ChunkBitmap>();
+        ChunkBitmap* entry = js_new<ChunkBitmap>();
         if (!entry)
             return;
 
@@ -4921,7 +4897,7 @@ MAKE_GC_SWEEP_TASK(SweepMiscTask);
 /* virtual */ void
 SweepAtomsTask::run()
 {
-    AtomMarkingRuntime::Bitmap marked;
+    DenseBitmap marked;
     if (runtime()->gc.atomMarking.computeBitmapFromChunkMarkBits(runtime(), marked)) {
         for (GCZonesIter zone(runtime()); !zone.done(); zone.next())
             runtime()->gc.atomMarking.updateZoneBitmap(zone, marked);
@@ -6313,7 +6289,7 @@ GCRuntime::gcCycle(bool nonincrementalByAPI, SliceBudget& budget, JS::gcreason::
 
     /* Clear gcMallocBytes for all zones. */
     for (ZonesIter zone(rt, WithAtoms); !zone.done(); zone.next())
-        zone->resetGCMallocBytes();
+        zone->resetAllMallocBytes();
 
     resetMallocBytes();
 
@@ -7621,7 +7597,8 @@ static bool
 ZoneGCAllocTriggerGetter(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
-    args.rval().setNumber(double(cx->zone()->threshold.allocTrigger(cx->runtime()->gc.schedulingState.inHighFrequencyGCMode())));
+    bool highFrequency = cx->runtime()->gc.schedulingState.inHighFrequencyGCMode();
+    args.rval().setNumber(double(cx->zone()->threshold.allocTrigger(highFrequency)));
     return true;
 }
 
@@ -7629,7 +7606,7 @@ static bool
 ZoneMallocBytesGetter(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
-    args.rval().setNumber(double(cx->zone()->gcMallocBytes));
+    args.rval().setNumber(double(cx->zone()->GCMallocBytes()));
     return true;
 }
 
@@ -7637,7 +7614,7 @@ static bool
 ZoneMaxMallocGetter(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
-    args.rval().setNumber(double(cx->zone()->gcMaxMallocBytes));
+    args.rval().setNumber(double(cx->zone()->GCMaxMallocBytes()));
     return true;
 }
 
diff --git a/js/src/jsgc.h b/js/src/jsgc.h
index e31d643960ec..b544d1b534f7 100644
--- a/js/src/jsgc.h
+++ b/js/src/jsgc.h
@@ -1018,24 +1018,27 @@ typedef void (*IterateCellCallback)(JSRuntime* rt, void* data, void* thing,
  * This function calls |zoneCallback| on every zone, |compartmentCallback| on
  * every compartment, |arenaCallback| on every in-use arena, and |cellCallback|
  * on every in-use cell in the GC heap.
+ *
+ * Note that no read barrier is triggered on the cells passed to cellCallback,
+ * so no these pointers must not escape the callback.
  */
 extern void
-IterateZonesCompartmentsArenasCells(JSContext* cx, void* data,
-                                    IterateZoneCallback zoneCallback,
-                                    JSIterateCompartmentCallback compartmentCallback,
-                                    IterateArenaCallback arenaCallback,
-                                    IterateCellCallback cellCallback);
+IterateHeapUnbarriered(JSContext* cx, void* data,
+                       IterateZoneCallback zoneCallback,
+                       JSIterateCompartmentCallback compartmentCallback,
+                       IterateArenaCallback arenaCallback,
+                       IterateCellCallback cellCallback);
 
 /*
  * This function is like IterateZonesCompartmentsArenasCells, but does it for a
  * single zone.
  */
 extern void
-IterateZoneCompartmentsArenasCells(JSContext* cx, Zone* zone, void* data,
-                                   IterateZoneCallback zoneCallback,
-                                   JSIterateCompartmentCallback compartmentCallback,
-                                   IterateArenaCallback arenaCallback,
-                                   IterateCellCallback cellCallback);
+IterateHeapUnbarrieredForZone(JSContext* cx, Zone* zone, void* data,
+                              IterateZoneCallback zoneCallback,
+                              JSIterateCompartmentCallback compartmentCallback,
+                              IterateArenaCallback arenaCallback,
+                              IterateCellCallback cellCallback);
 
 /*
  * Invoke chunkCallback on every in-use chunk.
diff --git a/js/src/jsgcinlines.h b/js/src/jsgcinlines.h
index 9ad1349da7eb..612c854b734d 100644
--- a/js/src/jsgcinlines.h
+++ b/js/src/jsgcinlines.h
@@ -154,8 +154,6 @@ class ArenaCellIterImpl
     void init(Arena* arena, CellIterNeedsBarrier mayNeedBarrier) {
         MOZ_ASSERT(!initialized);
         MOZ_ASSERT(arena);
-        MOZ_ASSERT_IF(!mayNeedBarrier,
-                      CurrentThreadIsPerformingGC() || CurrentThreadIsGCSweeping());
         initialized = true;
         AllocKind kind = arena->getAllocKind();
         firstThingOffset = Arena::firstThingOffset(kind);
@@ -243,6 +241,14 @@ class ArenaCellIterUnderFinalize : public ArenaCellIterImpl
     }
 };
 
+class ArenaCellIterUnbarriered : public ArenaCellIterImpl
+{
+  public:
+    explicit ArenaCellIterUnbarriered(Arena* arena)
+      : ArenaCellIterImpl(arena, CellIterDoesntNeedBarrier)
+    {}
+};
+
 template <typename T>
 class ZoneCellIter;
 
diff --git a/js/src/moz.build b/js/src/moz.build
index 2cd3d6bfb7c8..8b11432f99bc 100644
--- a/js/src/moz.build
+++ b/js/src/moz.build
@@ -176,6 +176,7 @@ UNIFIED_SOURCES += [
     'builtin/WeakMapObject.cpp',
     'builtin/WeakSetObject.cpp',
     'devtools/sharkctl.cpp',
+    'ds/Bitmap.cpp',
     'ds/LifoAlloc.cpp',
     'ds/MemoryProtectionExceptionHandler.cpp',
     'frontend/BytecodeCompiler.cpp',
diff --git a/js/src/proxy/CrossCompartmentWrapper.cpp b/js/src/proxy/CrossCompartmentWrapper.cpp
index ba25c40bd0de..5e14980980e7 100644
--- a/js/src/proxy/CrossCompartmentWrapper.cpp
+++ b/js/src/proxy/CrossCompartmentWrapper.cpp
@@ -513,20 +513,23 @@ JS_FRIEND_API(bool)
 js::NukeCrossCompartmentWrappers(JSContext* cx,
                                  const CompartmentFilter& sourceFilter,
                                  const CompartmentFilter& targetFilter,
-                                 js::NukeReferencesToWindow nukeReferencesToWindow)
+                                 js::NukeReferencesToWindow nukeReferencesToWindow,
+                                 js::NukeReferencesFromTarget nukeReferencesFromTarget)
 {
     CHECK_REQUEST(cx);
     JSRuntime* rt = cx->runtime();
 
     EvictAllNurseries(rt);
 
-    // Iterate through scopes looking for system cross compartment wrappers
-    // that point to an object that shares a global with obj.
-
     for (CompartmentsIter c(rt, SkipAtoms); !c.done(); c.next()) {
         if (!sourceFilter.match(c))
             continue;
 
+        // If the compartment matches both the source and target filter, we may
+        // want to cut both incoming and outgoing wrappers.
+        bool nukeAll = (nukeReferencesFromTarget == NukeAllReferences &&
+                        targetFilter.match(c));
+
         // Iterate the wrappers looking for anything interesting.
         for (JSCompartment::WrapperEnum e(c); !e.empty(); e.popFront()) {
             // Some cross-compartment wrappers are for strings.  We're not
@@ -538,13 +541,15 @@ js::NukeCrossCompartmentWrappers(JSContext* cx,
             AutoWrapperRooter wobj(cx, WrapperValue(e));
             JSObject* wrapped = UncheckedUnwrap(wobj);
 
+            // We only skip nuking window references that point to a target
+            // compartment, not the ones that belong to it.
             if (nukeReferencesToWindow == DontNukeWindowReferences &&
-                IsWindowProxy(wrapped))
+                MOZ_LIKELY(!nukeAll) && IsWindowProxy(wrapped))
             {
                 continue;
             }
 
-            if (targetFilter.match(wrapped->compartment())) {
+            if (MOZ_UNLIKELY(nukeAll) || targetFilter.match(wrapped->compartment())) {
                 // We found a wrapper to nuke.
                 e.removeFront();
                 NukeCrossCompartmentWrapper(cx, wobj);
diff --git a/js/src/shell/ModuleLoader.js b/js/src/shell/ModuleLoader.js
index d8767f05f4b0..58b095f4db10 100644
--- a/js/src/shell/ModuleLoader.js
+++ b/js/src/shell/ModuleLoader.js
@@ -21,9 +21,7 @@ Reflect.Loader = new class {
         return os.file.readFile(path);
     }
 
-    loadAndParse(name) {
-        let path = this.resolve(name);
-
+    loadAndParse(path) {
         if (this.registry.has(path))
             return this.registry.get(path);
 
@@ -33,11 +31,23 @@ Reflect.Loader = new class {
         return module;
     }
 
-    ["import"](name, referrer) {
-        let module = this.loadAndParse(name);
+    loadAndExecute(path) {
+        let module = this.loadAndParse(path);
         module.declarationInstantiation();
         return module.evaluation();
     }
+
+    importRoot(path) {
+        return this.loadAndExecute(path);
+    }
+
+    ["import"](name, referrer) {
+        let path = this.resolve(name);
+        return this.loadAndExecute(path);
+    }
 };
 
-setModuleResolveHook((module, requestName) => Reflect.Loader.loadAndParse(requestName));
+setModuleResolveHook((module, requestName) => {
+    let path = Reflect.Loader.resolve(requestName);
+    return Reflect.Loader.loadAndParse(path)
+});
diff --git a/js/src/shell/OSObject.cpp b/js/src/shell/OSObject.cpp
index d1019c77fd25..7d36295a3022 100644
--- a/js/src/shell/OSObject.cpp
+++ b/js/src/shell/OSObject.cpp
@@ -112,16 +112,18 @@ ResolvePath(JSContext* cx, HandleString filenameStr, PathResolutionMode resolveM
     if (IsAbsolutePath(filename))
         return filenameStr;
 
-    /* Get the currently executing script's name. */
     JS::AutoFilename scriptFilename;
-    if (!DescribeScriptedCaller(cx, &scriptFilename))
-        return nullptr;
+    if (resolveMode == ScriptRelative) {
+        // Get the currently executing script's name.
+        if (!DescribeScriptedCaller(cx, &scriptFilename))
+            return nullptr;
 
-    if (!scriptFilename.get())
-        return nullptr;
+        if (!scriptFilename.get())
+            return nullptr;
 
-    if (strcmp(scriptFilename.get(), "-e") == 0 || strcmp(scriptFilename.get(), "typein") == 0)
-        resolveMode = RootRelative;
+        if (strcmp(scriptFilename.get(), "-e") == 0 || strcmp(scriptFilename.get(), "typein") == 0)
+            resolveMode = RootRelative;
+    }
 
     static char buffer[PATH_MAX+1];
     if (resolveMode == ScriptRelative) {
diff --git a/js/src/shell/js.cpp b/js/src/shell/js.cpp
index 89e012c925e2..87e5112b9a7d 100644
--- a/js/src/shell/js.cpp
+++ b/js/src/shell/js.cpp
@@ -733,12 +733,12 @@ GetLoaderObject(JSContext* cx, MutableHandleObject resultOut)
 }
 
 static bool
-GetImportMethod(JSContext* cx, HandleObject loader, MutableHandleFunction resultOut)
+GetImportRootMethod(JSContext* cx, HandleObject loader, MutableHandleFunction resultOut)
 {
-    // Look up the module loader's |import| method.
+    // Look up the module loader's |importRoot| method.
 
     RootedValue value(cx);
-    if (!JS_GetProperty(cx, loader, "import", &value) || !value.isObject())
+    if (!JS_GetProperty(cx, loader, "importRoot", &value) || !value.isObject())
         return false;
 
     RootedObject object(cx, &value.toObject());
@@ -752,17 +752,31 @@ GetImportMethod(JSContext* cx, HandleObject loader, MutableHandleFunction result
 static MOZ_MUST_USE bool
 RunModule(JSContext* cx, const char* filename, FILE* file, bool compileOnly)
 {
-    // Execute a module by calling |Reflect.Loader.import(filename)|.
+    // Execute a module by calling Reflect.Loader.importRoot on the resolved
+    // filename.
 
     RootedObject loaderObj(cx);
-    MOZ_ALWAYS_TRUE(GetLoaderObject(cx, &loaderObj));
+    if (!GetLoaderObject(cx, &loaderObj)) {
+        JS_ReportErrorASCII(cx, "Failed to get Reflect.Loader");
+        return false;
+    }
 
     RootedFunction importFun(cx);
-    MOZ_ALWAYS_TRUE(GetImportMethod(cx, loaderObj, &importFun));
+    if (!GetImportRootMethod(cx, loaderObj, &importFun)) {
+        JS_ReportErrorASCII(cx, "Failed to get Reflect.Loader.importRoot method");
+        return false;
+    }
 
-    JS::AutoValueArray<2> args(cx);
-    args[0].setString(JS_NewStringCopyZ(cx, filename));
-    args[1].setUndefined();
+    RootedString path(cx, JS_NewStringCopyZ(cx, filename));
+    if (!path)
+        return false;
+
+    path = ResolvePath(cx, path, RootRelative);
+    if (!path)
+        return false;
+
+    JS::AutoValueArray<1> args(cx);
+    args[0].setString(path);
 
     RootedValue value(cx);
     return JS_CallFunction(cx, loaderObj, importFun, args, &value);
@@ -5037,6 +5051,24 @@ NewGlobal(JSContext* cx, unsigned argc, Value* vp)
     return true;
 }
 
+static bool
+NukeCCW(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    if (args.length() != 1 || !args[0].isObject() ||
+        !IsCrossCompartmentWrapper(&args[0].toObject()))
+    {
+        JS_ReportErrorNumberASCII(cx, my_GetErrorMessage, nullptr, JSSMSG_INVALID_ARGS,
+                                  "nukeCCW");
+        return false;
+    }
+
+    NukeCrossCompartmentWrapper(cx, &args[0].toObject());
+    args.rval().setUndefined();
+    return true;
+}
+
 static bool
 GetMaxArgs(JSContext* cx, unsigned argc, Value* vp)
 {
@@ -6366,6 +6398,10 @@ static const JSFunctionSpecWithHelp shell_functions[] = {
 "         principal is treated as if its bits were 0xffff, for subsumption\n"
 "         purposes. If this property is omitted, supply no principal."),
 
+    JS_FN_HELP("nukeCCW", NukeCCW, 1, 0,
+"nukeCCW(wrapper)",
+"  Nuke a CrossCompartmentWrapper, which turns it into a DeadProxyObject."),
+
     JS_FN_HELP("createMappedArrayBuffer", CreateMappedArrayBuffer, 1, 0,
 "createMappedArrayBuffer(filename, [offset, [size]])",
 "  Create an array buffer that mmaps the given file."),
diff --git a/js/src/tests/shell/futex-apis.js b/js/src/tests/shell/futex-apis.js
index b3e0acd55488..6df6ca3e3739 100644
--- a/js/src/tests/shell/futex-apis.js
+++ b/js/src/tests/shell/futex-apis.js
@@ -99,9 +99,8 @@ let sab = new SharedArrayBuffer(16);
     let indices = [ (view) => -1,
 		    (view) => view.length,
 		    (view) => view.length*2,
-		    (view) => undefined,
-		    (view) => '3.5',
-		    (view) => { password: "qumquat" } ];
+		    (view) => '-3.5',
+	            (view) => ({ valueOf: () => -8 }) ];
 
     for ( let iidx=0 ; iidx < indices.length ; iidx++ ) {
 	let Idx = indices[iidx](view);
diff --git a/js/src/vm/EnvironmentObject.cpp b/js/src/vm/EnvironmentObject.cpp
index cafc846668cc..e59842ef0461 100644
--- a/js/src/vm/EnvironmentObject.cpp
+++ b/js/src/vm/EnvironmentObject.cpp
@@ -488,7 +488,7 @@ ModuleEnvironmentObject::createImportBinding(JSContext* cx, HandleAtom importNam
 {
     RootedId importNameId(cx, AtomToId(importName));
     RootedId localNameId(cx, AtomToId(localName));
-    RootedModuleEnvironmentObject env(cx, module->environment());
+    RootedModuleEnvironmentObject env(cx, &module->initialEnvironment());
     if (!importBindings().putNew(cx, importNameId, env, localNameId)) {
         ReportOutOfMemory(cx);
         return false;
diff --git a/js/src/vm/MemoryMetrics.cpp b/js/src/vm/MemoryMetrics.cpp
index 4aa754eaeb72..fc9ab9149607 100644
--- a/js/src/vm/MemoryMetrics.cpp
+++ b/js/src/vm/MemoryMetrics.cpp
@@ -760,11 +760,11 @@ CollectRuntimeStatsHelper(JSContext* cx, RuntimeStats* rtStats, ObjectPrivateVis
     StatsClosure closure(rtStats, opv, anonymize);
     if (!closure.init())
         return false;
-    IterateZonesCompartmentsArenasCells(cx, &closure,
-                                        StatsZoneCallback,
-                                        StatsCompartmentCallback,
-                                        StatsArenaCallback,
-                                        statsCellCallback);
+    IterateHeapUnbarriered(cx, &closure,
+                                                   StatsZoneCallback,
+                                                   StatsCompartmentCallback,
+                                                   StatsArenaCallback,
+                                                   statsCellCallback);
 
     // Take the "explicit/js/runtime/" measurements.
     rt->addSizeOfIncludingThis(rtStats->mallocSizeOf_, &rtStats->runtime);
@@ -906,11 +906,11 @@ AddSizeOfTab(JSContext* cx, HandleObject obj, MallocSizeOf mallocSizeOf, ObjectP
     StatsClosure closure(&rtStats, opv, /* anonymize = */ false);
     if (!closure.init())
         return false;
-    IterateZoneCompartmentsArenasCells(cx, zone, &closure,
-                                       StatsZoneCallback,
-                                       StatsCompartmentCallback,
-                                       StatsArenaCallback,
-                                       StatsCellCallback<CoarseGrained>);
+    IterateHeapUnbarrieredForZone(cx, zone, &closure,
+                                                  StatsZoneCallback,
+                                                  StatsCompartmentCallback,
+                                                  StatsArenaCallback,
+                                                  StatsCellCallback<CoarseGrained>);
 
     MOZ_ASSERT(rtStats.zoneStatsVector.length() == 1);
     rtStats.zTotals.addSizes(rtStats.zoneStatsVector[0]);
diff --git a/js/src/wasm/WasmBaselineCompile.cpp b/js/src/wasm/WasmBaselineCompile.cpp
index 8de489e1f87e..c66f02c95b2d 100644
--- a/js/src/wasm/WasmBaselineCompile.cpp
+++ b/js/src/wasm/WasmBaselineCompile.cpp
@@ -489,7 +489,6 @@ class BaseCompiler
     ValTypeVector               Sig_;
     Label                       returnLabel_;
     Label                       stackOverflowLabel_;
-    TrapOffset                  prologueTrapOffset_;
     CodeOffset                  stackAddOffset_;
 
     LatentOp                    latentOp_;       // Latent operation for branch (seen next)
@@ -2046,31 +2045,31 @@ class BaseCompiler
         AllocatableGeneralRegisterSet knownGPR_ = availGPR_;
         AllocatableFloatRegisterSet knownFPU_ = availFPU_;
         for (size_t i = 0 ; i < stk_.length() ; i++) {
-	    Stk& item = stk_[i];
-	    switch (item.kind_) {
-	      case Stk::RegisterI32:
-		knownGPR_.add(item.i32reg());
-		break;
-	      case Stk::RegisterI64:
+            Stk& item = stk_[i];
+            switch (item.kind_) {
+              case Stk::RegisterI32:
+                knownGPR_.add(item.i32reg());
+                break;
+              case Stk::RegisterI64:
 #ifdef JS_PUNBOX64
-		knownGPR_.add(item.i64reg().reg);
+                knownGPR_.add(item.i64reg().reg);
 #else
-		knownGPR_.add(item.i64reg().high);
-		knownGPR_.add(item.i64reg().low);
+                knownGPR_.add(item.i64reg().high);
+                knownGPR_.add(item.i64reg().low);
 #endif
-		break;
-	      case Stk::RegisterF32:
-		knownFPU_.add(item.f32reg());
-		break;
-	      case Stk::RegisterF64:
-		knownFPU_.add(item.f64reg());
-		break;
-	      default:
-		break;
-	    }
-	}
-	MOZ_ASSERT(knownGPR_.bits() == allGPR_.bits());
-	MOZ_ASSERT(knownFPU_.bits() == allFPU_.bits());
+                break;
+              case Stk::RegisterF32:
+                knownFPU_.add(item.f32reg());
+                break;
+              case Stk::RegisterF64:
+                knownFPU_.add(item.f64reg());
+                break;
+              default:
+                break;
+            }
+        }
+        MOZ_ASSERT(knownGPR_.bits() == allGPR_.bits());
+        MOZ_ASSERT(knownFPU_.bits() == allFPU_.bits());
     }
 #endif
 
@@ -2106,8 +2105,7 @@ class BaseCompiler
     // Labels
 
     void insertBreakablePoint(CallSiteDesc::Kind kind) {
-        const uint32_t offset = trapOffset().bytecodeOffset;
-        masm.nopPatchableToCall(CallSiteDesc(offset, kind));
+        masm.nopPatchableToCall(CallSiteDesc(iter_.errorOffset(), kind));
     }
 
     //////////////////////////////////////////////////////////////////////
@@ -2271,7 +2269,8 @@ class BaseCompiler
         MOZ_ASSERT(localSize_ >= debugFrameReserved);
         if (localSize_ > debugFrameReserved)
             masm.addToStackPtr(Imm32(localSize_ - debugFrameReserved));
-        masm.jump(TrapDesc(prologueTrapOffset_, Trap::StackOverflow, debugFrameReserved));
+        TrapOffset prologueTrapOffset(func_.lineOrBytecode());
+        masm.jump(TrapDesc(prologueTrapOffset, Trap::StackOverflow, debugFrameReserved));
 
         masm.bind(&returnLabel_);
 
@@ -2389,7 +2388,10 @@ class BaseCompiler
 
     void startCallArgs(FunctionCall& call, size_t stackArgAreaSize)
     {
-        call.stackArgAreaSize = stackArgAreaSize;
+        // It's possible the TLS pointer may have implicitly used stack before.
+        MOZ_ASSERT(call.stackArgAreaSize == 0 || call.stackArgAreaSize == sizeof(void*));
+
+        call.stackArgAreaSize += stackArgAreaSize;
 
         size_t adjustment = call.stackArgAreaSize + call.frameAlignAdjustment;
         if (adjustment)
@@ -2397,7 +2399,10 @@ class BaseCompiler
     }
 
     const ABIArg reservePointerArgument(FunctionCall& call) {
-        return call.abi.next(MIRType::Pointer);
+        ABIArg ret = call.abi.next(MIRType::Pointer);
+        if (ret.kind() == ABIArg::Stack)
+            call.stackArgAreaSize += sizeof(void*);
+        return ret;
     }
 
     // TODO / OPTIMIZE (Bug 1316821): Note passArg is used only in one place.
@@ -2908,7 +2913,8 @@ class BaseCompiler
         // movl clears the high bits if the two registers are the same.
         masm.movl(src.reg, dest);
 #elif defined(JS_NUNBOX32)
-        masm.move32(src.low, dest);
+        if (src.low != dest)
+            masm.move32(src.low, dest);
 #else
         MOZ_CRASH("BaseCompiler platform hook: wrapI64ToI32");
 #endif
@@ -2947,7 +2953,8 @@ class BaseCompiler
 #if defined(JS_CODEGEN_X64)
         masm.movl(src, dest.reg);
 #elif defined(JS_NUNBOX32)
-        masm.move32(src, dest.low);
+        if (src != dest.low)
+            masm.move32(src, dest.low);
         masm.move32(Imm32(0), dest.high);
 #else
         MOZ_CRASH("BaseCompiler platform hook: extendU32ToI64");
@@ -3505,7 +3512,7 @@ class BaseCompiler
     uint32_t readCallSiteLineOrBytecode() {
         if (!func_.callSiteLineNums().empty())
             return func_.callSiteLineNums()[lastReadCallSite_++];
-        return trapOffset().bytecodeOffset;
+        return iter_.errorOffset();
     }
 
     bool done() const {
@@ -7326,7 +7333,7 @@ BaseCompiler::BaseCompiler(const ModuleEnvironment& env,
                            TempAllocator* alloc,
                            MacroAssembler* masm)
     : env_(env),
-      iter_(env, decoder, func.lineOrBytecode()),
+      iter_(env, decoder),
       func_(func),
       lastReadCallSite_(0),
       alloc_(*alloc),
@@ -7338,7 +7345,6 @@ BaseCompiler::BaseCompiler(const ModuleEnvironment& env,
       deadCode_(false),
       debugEnabled_(debugEnabled),
       bceSafe_(0),
-      prologueTrapOffset_(trapOffset()),
       stackAddOffset_(0),
       latentOp_(LatentOp::None),
       latentType_(ValType::I32),
@@ -7539,7 +7545,7 @@ js::wasm::BaselineCompileFunction(CompileTask* task, FuncCompileUnit* unit, Uniq
     const FuncBytes& func = unit->func();
     uint32_t bodySize = func.bytes().length();
 
-    Decoder d(func.bytes(), error);
+    Decoder d(func.bytes().begin(), func.bytes().end(), func.lineOrBytecode(), error);
 
     if (!ValidateFunctionBody(task->env(), func.index(), bodySize, d))
         return false;
diff --git a/js/src/wasm/WasmBinaryConstants.h b/js/src/wasm/WasmBinaryConstants.h
index ca240f0a87b7..50253cfc18e8 100644
--- a/js/src/wasm/WasmBinaryConstants.h
+++ b/js/src/wasm/WasmBinaryConstants.h
@@ -27,10 +27,6 @@ namespace wasm {
 static const uint32_t MagicNumber        = 0x6d736100; // "\0asm"
 static const uint32_t EncodingVersion    = 0x01;
 
-// 0xd is equivalent to 0x1 modulo unreachability validation rules, so to aid
-// transition of toolchain, accept both for a short period of time.
-static const uint32_t PrevEncodingVersion = 0x0d;
-
 static const char NameSectionName[]      = "name";
 
 enum class SectionId
diff --git a/js/src/wasm/WasmBinaryIterator.h b/js/src/wasm/WasmBinaryIterator.h
index 5048eaf320ba..bae3edb8776f 100644
--- a/js/src/wasm/WasmBinaryIterator.h
+++ b/js/src/wasm/WasmBinaryIterator.h
@@ -326,13 +326,12 @@ class MOZ_STACK_CLASS OpIter : private Policy
 
     Decoder& d_;
     const ModuleEnvironment& env_;
-    const size_t offsetInModule_;
 
     Vector<TypeAndValue<Value>, 8, SystemAllocPolicy> valueStack_;
     Vector<ControlStackEntry<ControlItem>, 8, SystemAllocPolicy> controlStack_;
 
     DebugOnly<Op> op_;
-    size_t offsetOfExpr_;
+    size_t offsetOfLastReadOp_;
 
     MOZ_MUST_USE bool readFixedU8(uint8_t* out) {
         if (Validate)
@@ -485,8 +484,8 @@ class MOZ_STACK_CLASS OpIter : private Policy
   public:
     typedef Vector<Value, 8, SystemAllocPolicy> ValueVector;
 
-    explicit OpIter(const ModuleEnvironment& env, Decoder& decoder, uint32_t offsetInModule = 0)
-      : d_(decoder), env_(env), offsetInModule_(offsetInModule), op_(Op::Limit), offsetOfExpr_(0)
+    explicit OpIter(const ModuleEnvironment& env, Decoder& decoder)
+      : d_(decoder), env_(env), op_(Op::Limit), offsetOfLastReadOp_(0)
     {}
 
     // Return the decoding byte offset.
@@ -494,9 +493,14 @@ class MOZ_STACK_CLASS OpIter : private Policy
         return d_.currentOffset();
     }
 
-    // Returning the offset within the entire module of the last-read Op.
+    // Return the offset within the entire module of the last-read op.
+    size_t errorOffset() const {
+        return offsetOfLastReadOp_ ? offsetOfLastReadOp_ : d_.currentOffset();
+    }
+
+    // Return a TrapOffset describing where the current op should be reported to trap.
     TrapOffset trapOffset() const {
-        return TrapOffset(offsetInModule_ + offsetOfExpr_);
+        return TrapOffset(errorOffset());
     }
 
     // Test whether the iterator has reached the end of the buffer.
@@ -661,7 +665,7 @@ template <typename Policy>
 inline bool
 OpIter<Policy>::fail(const char* msg)
 {
-    return d_.fail("%s", msg);
+    return d_.fail(errorOffset(), msg);
 }
 
 // This function pops exactly one value from the stack, yielding Any types in
@@ -904,7 +908,7 @@ OpIter<Policy>::readOp(uint16_t* op)
 {
     MOZ_ASSERT(!controlStack_.empty());
 
-    offsetOfExpr_ = d_.currentOffset();
+    offsetOfLastReadOp_ = d_.currentOffset();
 
     if (Validate) {
         if (MOZ_UNLIKELY(!d_.readOp(op)))
diff --git a/js/src/wasm/WasmBinaryToAST.cpp b/js/src/wasm/WasmBinaryToAST.cpp
index 0296ed8a7d51..6c03543b54f5 100644
--- a/js/src/wasm/WasmBinaryToAST.cpp
+++ b/js/src/wasm/WasmBinaryToAST.cpp
@@ -1855,7 +1855,7 @@ wasm::BinaryToAst(JSContext* cx, const uint8_t* bytes, uint32_t length, LifoAllo
         return false;
 
     UniqueChars error;
-    Decoder d(bytes, bytes + length, &error, /* resilient */ true);
+    Decoder d(bytes, bytes + length, 0, &error, /* resilient */ true);
     AstDecodeContext c(cx, lifo, d, *result, true);
 
     if (!AstDecodeEnvironment(c) ||
diff --git a/js/src/wasm/WasmCode.cpp b/js/src/wasm/WasmCode.cpp
index bb65b45adad4..623d95095592 100644
--- a/js/src/wasm/WasmCode.cpp
+++ b/js/src/wasm/WasmCode.cpp
@@ -88,6 +88,8 @@ AllocateCodeSegment(JSContext* cx, uint32_t codeLength)
         return nullptr;
     }
 
+    cx->zone()->updateJitCodeMallocBytes(codeLength);
+
     wasmCodeAllocations++;
     return (uint8_t*)p;
 }
@@ -259,7 +261,6 @@ CodeSegment::~CodeSegment()
     if (!bytes_)
         return;
 
-
     MOZ_ASSERT(wasmCodeAllocations > 0);
     wasmCodeAllocations--;
 
@@ -271,7 +272,6 @@ CodeSegment::~CodeSegment()
     vtune::UnmarkBytes(bytes_, size);
 #endif
     DeallocateExecutableMemory(bytes_, size);
-
 }
 
 void
diff --git a/js/src/wasm/WasmCompile.cpp b/js/src/wasm/WasmCompile.cpp
index 5a5916f031b6..0dbf45ec80e0 100644
--- a/js/src/wasm/WasmCompile.cpp
+++ b/js/src/wasm/WasmCompile.cpp
@@ -110,7 +110,7 @@ wasm::Compile(const ShareableBytes& bytecode, const CompileArgs& args, UniqueCha
 {
     MOZ_RELEASE_ASSERT(wasm::HaveSignalHandlers());
 
-    Decoder d(bytecode.begin(), bytecode.end(), error);
+    Decoder d(bytecode.bytes, error);
 
     auto env = js::MakeUnique<ModuleEnvironment>();
     if (!env)
diff --git a/js/src/wasm/WasmIonCompile.cpp b/js/src/wasm/WasmIonCompile.cpp
index 3953dbd46e67..0d468408d60b 100644
--- a/js/src/wasm/WasmIonCompile.cpp
+++ b/js/src/wasm/WasmIonCompile.cpp
@@ -176,7 +176,7 @@ class FunctionCompiler
                      const ValTypeVector& locals,
                      MIRGenerator& mirGen)
       : env_(env),
-        iter_(env, decoder, func.lineOrBytecode()),
+        iter_(env, decoder),
         func_(func),
         locals_(locals),
         lastReadCallSite_(0),
@@ -1509,7 +1509,7 @@ class FunctionCompiler
     uint32_t readCallSiteLineOrBytecode() {
         if (!func_.callSiteLineNums().empty())
             return func_.callSiteLineNums()[lastReadCallSite_++];
-        return iter_.trapOffset().bytecodeOffset;
+        return iter_.errorOffset();
     }
 
     bool done() const { return iter_.done(); }
@@ -2997,7 +2997,7 @@ EmitCurrentMemory(FunctionCompiler& f)
     if (!f.passInstance(&args))
         return false;
 
-    f.finishCall(&args, TlsUsage::Unused);
+    f.finishCall(&args, TlsUsage::Need);
 
     MDefinition* ret;
     if (!f.builtinInstanceMethodCall(SymbolicAddress::CurrentMemory, args, ValType::I32, &ret))
@@ -3618,7 +3618,7 @@ wasm::IonCompileFunction(CompileTask* task, FuncCompileUnit* unit, UniqueChars*
     const ModuleEnvironment& env = task->env();
     uint32_t bodySize = func.bytes().length();
 
-    Decoder d(func.bytes(), error);
+    Decoder d(func.bytes().begin(), func.bytes().end(), func.lineOrBytecode(), error);
 
     if (!env.isAsmJS()) {
         if (!ValidateFunctionBody(task->env(), func.index(), bodySize, d))
@@ -3645,18 +3645,12 @@ wasm::IonCompileFunction(CompileTask* task, FuncCompileUnit* unit, UniqueChars*
                      IonOptimizations.get(OptimizationLevel::Wasm));
     mir.initMinWasmHeapLength(env.minMemoryLength);
 
-    // Capture the prologue's trap site before decoding the function.
-
-    TrapOffset prologueTrapOffset;
-
     // Build MIR graph
     {
         FunctionCompiler f(env, d, func, locals, mir);
         if (!f.init())
             return false;
 
-        prologueTrapOffset = f.iter().trapOffset();
-
         if (!f.startBlock())
             return false;
 
@@ -3695,6 +3689,7 @@ wasm::IonCompileFunction(CompileTask* task, FuncCompileUnit* unit, UniqueChars*
 
         CodeGenerator codegen(&mir, lir, &task->masm());
 
+        TrapOffset prologueTrapOffset(func.lineOrBytecode());
         FuncOffsets offsets;
         if (!codegen.generateWasm(sigId, prologueTrapOffset, &offsets))
             return false;
diff --git a/js/src/wasm/WasmValidate.cpp b/js/src/wasm/WasmValidate.cpp
index 09a19f0a38c8..c68d152f17f3 100644
--- a/js/src/wasm/WasmValidate.cpp
+++ b/js/src/wasm/WasmValidate.cpp
@@ -34,7 +34,7 @@ using mozilla::CheckedInt;
 // Decoder implementation.
 
 bool
-Decoder::fail(const char* msg, ...)
+Decoder::failf(const char* msg, ...)
 {
     va_list ap;
     va_start(ap, msg);
@@ -43,14 +43,14 @@ Decoder::fail(const char* msg, ...)
     if (!str)
         return false;
 
-    return fail(Move(str));
+    return fail(str.get());
 }
 
 bool
-Decoder::fail(UniqueChars msg)
+Decoder::fail(size_t errorOffset, const char* msg)
 {
     MOZ_ASSERT(error_);
-    UniqueChars strWithOffset(JS_smprintf("at offset %" PRIuSIZE ": %s", currentOffset(), msg.get()));
+    UniqueChars strWithOffset(JS_smprintf("at offset %" PRIuSIZE ": %s", errorOffset, msg));
     if (!strWithOffset)
         return false;
 
@@ -110,7 +110,7 @@ Decoder::startSection(SectionId id, ModuleEnvironment* env, uint32_t* sectionSta
     return true;
 
   fail:
-    return fail("failed to start %s section", sectionName);
+    return failf("failed to start %s section", sectionName);
 }
 
 bool
@@ -119,7 +119,7 @@ Decoder::finishSection(uint32_t sectionStart, uint32_t sectionSize, const char*
     if (resilientMode_)
         return true;
     if (sectionSize != (cur_ - beg_) - sectionStart)
-        return fail("byte size mismatch in %s section", sectionName);
+        return failf("byte size mismatch in %s section", sectionName);
     return true;
 }
 
@@ -617,9 +617,9 @@ DecodePreamble(Decoder& d)
     if (!d.readFixedU32(&u32) || u32 != MagicNumber)
         return d.fail("failed to match magic number");
 
-    if (!d.readFixedU32(&u32) || (u32 != EncodingVersion && u32 != PrevEncodingVersion)) {
-        return d.fail("binary version 0x%" PRIx32 " does not match expected version 0x%" PRIx32,
-                      u32, EncodingVersion);
+    if (!d.readFixedU32(&u32) || u32 != EncodingVersion) {
+        return d.failf("binary version 0x%" PRIx32 " does not match expected version 0x%" PRIx32,
+                       u32, EncodingVersion);
     }
 
     return true;
@@ -735,7 +735,7 @@ DecodeLimits(Decoder& d, Limits* limits)
         return d.fail("expected flags");
 
     if (flags & ~uint32_t(0x1))
-        return d.fail("unexpected bits set in flags: %" PRIu32, (flags & ~uint32_t(0x1)));
+        return d.failf("unexpected bits set in flags: %" PRIu32, (flags & ~uint32_t(0x1)));
 
     if (!d.readVarU32(&limits->initial))
         return d.fail("expected initial length");
@@ -746,9 +746,9 @@ DecodeLimits(Decoder& d, Limits* limits)
             return d.fail("expected maximum length");
 
         if (limits->initial > maximum) {
-            return d.fail("memory size minimum must not be greater than maximum; "
-                          "maximum length %" PRIu32 " is less than initial length %" PRIu32,
-                          maximum, limits->initial);
+            return d.failf("memory size minimum must not be greater than maximum; "
+                           "maximum length %" PRIu32 " is less than initial length %" PRIu32,
+                           maximum, limits->initial);
         }
 
         limits->maximum.emplace(maximum);
@@ -1580,7 +1580,7 @@ wasm::DecodeModuleTail(Decoder& d, ModuleEnvironment* env)
 bool
 wasm::Validate(const ShareableBytes& bytecode, UniqueChars* error)
 {
-    Decoder d(bytecode.begin(), bytecode.end(), error);
+    Decoder d(bytecode.bytes, error);
 
     ModuleEnvironment env;
     if (!DecodeModuleEnvironment(d, &env))
diff --git a/js/src/wasm/WasmValidate.h b/js/src/wasm/WasmValidate.h
index 49dfe2eb31fc..cae95917abb9 100644
--- a/js/src/wasm/WasmValidate.h
+++ b/js/src/wasm/WasmValidate.h
@@ -302,6 +302,7 @@ class Decoder
     const uint8_t* const beg_;
     const uint8_t* const end_;
     const uint8_t* cur_;
+    const size_t offsetInModule_;
     UniqueChars* error_;
     bool resilientMode_;
 
@@ -384,11 +385,12 @@ class Decoder
     }
 
   public:
-    Decoder(const uint8_t* begin, const uint8_t* end, UniqueChars* error,
+    Decoder(const uint8_t* begin, const uint8_t* end, size_t offsetInModule, UniqueChars* error,
             bool resilientMode = false)
       : beg_(begin),
         end_(end),
         cur_(begin),
+        offsetInModule_(offsetInModule),
         error_(error),
         resilientMode_(resilientMode)
     {
@@ -398,12 +400,18 @@ class Decoder
       : beg_(bytes.begin()),
         end_(bytes.end()),
         cur_(bytes.begin()),
+        offsetInModule_(0),
         error_(error),
         resilientMode_(false)
     {}
 
-    bool fail(const char* msg, ...) MOZ_FORMAT_PRINTF(2, 3);
-    bool fail(UniqueChars msg);
+    // These convenience functions use currentOffset() as the errorOffset.
+    bool fail(const char* msg) { return fail(currentOffset(), msg); }
+    bool failf(const char* msg, ...) MOZ_FORMAT_PRINTF(2, 3);
+
+    // Report an error at the given offset (relative to the whole module).
+    bool fail(size_t errorOffset, const char* msg);
+
     void clearError() {
         if (error_)
             error_->reset();
@@ -429,7 +437,7 @@ class Decoder
         return cur_;
     }
     size_t currentOffset() const {
-        return cur_ - beg_;
+        return offsetInModule_ + (cur_ - beg_);
     }
     const uint8_t* begin() const {
         return beg_;
diff --git a/js/xpconnect/src/XPCComponents.cpp b/js/xpconnect/src/XPCComponents.cpp
index 7a4f71975ecd..8b1876ff3b9a 100644
--- a/js/xpconnect/src/XPCComponents.cpp
+++ b/js/xpconnect/src/XPCComponents.cpp
@@ -3020,14 +3020,8 @@ nsXPCComponents_Utils::NukeSandbox(HandleValue obj, JSContext* cx)
     NS_ENSURE_TRUE(IsWrapper(wrapper), NS_ERROR_INVALID_ARG);
     RootedObject sb(cx, UncheckedUnwrap(wrapper));
     NS_ENSURE_TRUE(IsSandbox(sb), NS_ERROR_INVALID_ARG);
-    NukeCrossCompartmentWrappers(cx, AllCompartments(),
-                                 SingleCompartment(GetObjectCompartment(sb)),
-                                 NukeWindowReferences);
 
-    // Now mark the compartment as nuked and non-scriptable.
-    auto compartmentPrivate = xpc::CompartmentPrivate::Get(sb);
-    compartmentPrivate->wasNuked = true;
-    compartmentPrivate->scriptability.Block();
+    xpc::NukeAllWrappersForCompartment(cx, GetObjectCompartment(sb));
 
     return NS_OK;
 }
diff --git a/js/xpconnect/src/XPCJSContext.cpp b/js/xpconnect/src/XPCJSContext.cpp
index 7cc451990926..d52bd6f1b9ea 100644
--- a/js/xpconnect/src/XPCJSContext.cpp
+++ b/js/xpconnect/src/XPCJSContext.cpp
@@ -580,6 +580,37 @@ CurrentWindowOrNull(JSContext* cx)
     return glob ? WindowOrNull(glob) : nullptr;
 }
 
+// Nukes all wrappers into or out of the given compartment, and prevents new
+// wrappers from being created. Additionally marks the compartment as
+// unscriptable after wrappers have been nuked.
+//
+// Note: This should *only* be called for browser or extension compartments.
+// Wrappers between web compartments must never be cut in web-observable
+// ways.
+void
+NukeAllWrappersForCompartment(JSContext* cx, JSCompartment* compartment,
+                              js::NukeReferencesToWindow nukeReferencesToWindow)
+{
+    // First, nuke all wrappers into or out of the target compartment. Once
+    // the compartment is marked as nuked, WrapperFactory will refuse to
+    // create new live wrappers for it, in either direction. This means that
+    // we need to be sure that we don't have any existing cross-compartment
+    // wrappers which may be replaced with dead wrappers during unrelated
+    // wrapper recomputation *before* we set that bit.
+    js::NukeCrossCompartmentWrappers(cx, js::AllCompartments(),
+                                     js::SingleCompartment(compartment),
+                                     nukeReferencesToWindow,
+                                     js::NukeAllReferences);
+
+    // At this point, we should cross-compartment wrappers for the nuked
+    // compartment. Set the wasNuked bit so WrapperFactory will return a
+    // DeadObjectProxy when asked to create a new wrapper for it, and mark as
+    // unscriptable.
+    auto compartmentPrivate = xpc::CompartmentPrivate::Get(compartment);
+    compartmentPrivate->wasNuked = true;
+    compartmentPrivate->scriptability.Block();
+}
+
 } // namespace xpc
 
 static void
diff --git a/js/xpconnect/src/xpcpublic.h b/js/xpconnect/src/xpcpublic.h
index 38375d00a17e..5115b7ea198f 100644
--- a/js/xpconnect/src/xpcpublic.h
+++ b/js/xpconnect/src/xpcpublic.h
@@ -400,6 +400,9 @@ bool StringToJsval(JSContext* cx, mozilla::dom::DOMString& str,
 
 nsIPrincipal* GetCompartmentPrincipal(JSCompartment* compartment);
 
+void NukeAllWrappersForCompartment(JSContext* cx, JSCompartment* compartment,
+                                   js::NukeReferencesToWindow nukeReferencesToWindow = js::NukeWindowReferences);
+
 void SetLocationForGlobal(JSObject* global, const nsACString& location);
 void SetLocationForGlobal(JSObject* global, nsIURI* locationURI);
 
diff --git a/js/xpconnect/tests/mochitest/mochitest.ini b/js/xpconnect/tests/mochitest/mochitest.ini
index de6759e7ab7c..ffac4cc8f4a6 100644
--- a/js/xpconnect/tests/mochitest/mochitest.ini
+++ b/js/xpconnect/tests/mochitest/mochitest.ini
@@ -101,6 +101,7 @@ support-files =
 [test_getWebIDLCaller.html]
 skip-if = (debug == false || os == "android")
 [test_nac.xhtml]
+[test_nukeContentWindow.html]
 [test_sameOriginPolicy.html]
 [test_sandbox_fetch.html]
   support-files =
diff --git a/js/xpconnect/tests/mochitest/test_nukeContentWindow.html b/js/xpconnect/tests/mochitest/test_nukeContentWindow.html
new file mode 100644
index 000000000000..ce2fd2a89356
--- /dev/null
+++ b/js/xpconnect/tests/mochitest/test_nukeContentWindow.html
@@ -0,0 +1,61 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1322273
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test for Bug 1322273</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="application/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1322273">Mozilla Bug 1322273</a>
+
+<iframe id="subframe"></iframe>
+
+<script type="application/javascript">
+"use strict";
+
+add_task(function* () {
+  let frame = $('subframe');
+  frame.src = "data:text/html,";
+  yield new Promise(resolve => frame.addEventListener("load", resolve, {once: true}));
+
+  let win = frame.contentWindow;
+
+  win.eval("obj = {}");
+  win.obj.foo = {bar: "baz"};
+
+  let obj = win.obj;
+
+  let system = SpecialPowers.Services.scriptSecurityManager.getSystemPrincipal()
+  let sandbox = SpecialPowers.Cu.Sandbox(system);
+
+  sandbox.obj = obj;
+
+  let isWrapperDead = SpecialPowers.Cu.evalInSandbox(`(${
+      function isWrapperDead() {
+        return Components.utils.isDeadWrapper(obj);
+      }
+    })`,
+    sandbox);
+
+  is(isWrapperDead(), false, "Sandbox wrapper for content window should not be dead");
+  is(obj.foo.bar, "baz", "Content wrappers into and out of content window should be alive");
+
+  // Remove the frame, which should nuke the content window.
+  info("Remove the content frame");
+  frame.remove();
+
+  // Give the nuke wrappers task a chance to run.
+  yield new Promise(SimpleTest.executeSoon);
+
+  is(isWrapperDead(), true, "Sandbox wrapper for content window should be dead");
+  is(obj.foo.bar, "baz", "Content wrappers into and out of content window should be alive");
+});
+</script>
+
+</body>
+</html>
diff --git a/js/xpconnect/tests/unit/test_nuke_sandbox.js b/js/xpconnect/tests/unit/test_nuke_sandbox.js
index a4dd25498af1..9659902610d8 100644
--- a/js/xpconnect/tests/unit/test_nuke_sandbox.js
+++ b/js/xpconnect/tests/unit/test_nuke_sandbox.js
@@ -4,20 +4,46 @@
 
 /* See https://bugzilla.mozilla.org/show_bug.cgi?id=769273 */
 
+const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
+
+const global = this;
+
 function run_test()
 {
-  var sb = Components.utils.Sandbox("http://www.blah.com");
+  var ifacePointer = Cc["@mozilla.org/supports-interface-pointer;1"]
+      .createInstance(Ci.nsISupportsInterfacePointer);
+
+  var sb = Cu.Sandbox(global);
   sb.prop = "prop"
-  var refToObjFromSb = Components.utils.evalInSandbox("var a = {prop2:'prop2'}; a", sb); 
-  Components.utils.nukeSandbox(sb);
-  do_check_true(Components.utils.isDeadWrapper(sb), "sb should be dead");
+  sb.ifacePointer = ifacePointer
+
+  var refToObjFromSb = Cu.evalInSandbox(`
+    Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+
+    ifacePointer.data = {
+      QueryInterface: XPCOMUtils.generateQI([]),
+      wrappedJSObject: {foo: "bar"},
+    };
+
+    var a = {prop2:'prop2'};
+    a
+  `, sb);
+
+  equal(ifacePointer.data.wrappedJSObject.foo, "bar",
+        "Got expected wrapper into sandbox")
+
+  Cu.nukeSandbox(sb);
+  ok(Cu.isDeadWrapper(sb), "sb should be dead");
+  ok(Cu.isDeadWrapper(ifacePointer.data.wrappedJSObject),
+     "Wrapper retrieved via XPConnect should be dead");
+
   try{
     sb.prop;
     do_check_true(false);
   } catch (e) {
     do_check_true(e.toString().indexOf("can't access dead object") > -1);
   }
-  
+
   Components.utils.isDeadWrapper(refToObjFromSb, "ref to object from sb should be dead");
   try{
     refToObjFromSb.prop2;
@@ -25,5 +51,4 @@ function run_test()
   } catch (e) {
     do_check_true(e.toString().indexOf("can't access dead object") > -1);
   }
-  
 }
diff --git a/js/xpconnect/wrappers/WrapperFactory.cpp b/js/xpconnect/wrappers/WrapperFactory.cpp
index bdb727841f08..c9ae96b7ff92 100644
--- a/js/xpconnect/wrappers/WrapperFactory.cpp
+++ b/js/xpconnect/wrappers/WrapperFactory.cpp
@@ -181,6 +181,24 @@ WrapperFactory::PrepareForWrapping(JSContext* cx, HandleObject scope,
         ExposeObjectToActiveJS(obj);
     }
 
+    // If we've somehow gotten to this point after either the source or target
+    // compartment has been nuked, return a DeadObjectProxy to prevent further
+    // access.
+    JSCompartment* origin = js::GetObjectCompartment(obj);
+    JSCompartment* target = js::GetObjectCompartment(scope);
+    if (CompartmentPrivate::Get(origin)->wasNuked ||
+        CompartmentPrivate::Get(target)->wasNuked) {
+        NS_WARNING("Trying to create a wrapper into or out of a nuked compartment");
+
+        RootedObject ccw(cx, Wrapper::New(cx, obj, &CrossCompartmentWrapper::singleton));
+
+        NukeCrossCompartmentWrapper(cx, ccw);
+
+        retObj.set(ccw);
+        return;
+    }
+
+
     // If we've got a WindowProxy, there's nothing special that needs to be
     // done here, and we can move on to the next phase of wrapping. We handle
     // this case first to allow us to assert against wrappers below.
@@ -332,8 +350,10 @@ DEBUG_CheckUnwrapSafety(HandleObject obj, const js::Wrapper* handler,
                         JSCompartment* origin, JSCompartment* target)
 {
     if (CompartmentPrivate::Get(origin)->wasNuked || CompartmentPrivate::Get(target)->wasNuked) {
-        // If either compartment has already been nuked, we should have an opaque wrapper.
-        MOZ_ASSERT(handler->hasSecurityPolicy());
+        // If either compartment has already been nuked, we should have returned
+        // a dead wrapper from our prewrap callback, and this function should
+        // not be called.
+        MOZ_ASSERT_UNREACHABLE("CheckUnwrapSafety called for a dead wrapper");
     } else if (AccessCheck::isChrome(target) || xpc::IsUniversalXPConnectEnabled(target)) {
         // If the caller is chrome (or effectively so), unwrap should always be allowed.
         MOZ_ASSERT(!handler->hasSecurityPolicy());
@@ -457,21 +477,9 @@ WrapperFactory::Rewrap(JSContext* cx, HandleObject existing, HandleObject obj)
     // First, handle the special cases.
     //
 
-    // If we've somehow gotten to this point after either the source or target
-    // compartment has been nuked, return an opaque wrapper to prevent further
-    // access.
-    // Ideally, we should return a DeadProxyObject instead of a wrapper in this
-    // case (bug 1322273).
-    if (CompartmentPrivate::Get(origin)->wasNuked ||
-        CompartmentPrivate::Get(target)->wasNuked) {
-        NS_WARNING("Trying to create a wrapper into or out of a nuked compartment");
-
-        wrapper = &FilteringWrapper<CrossCompartmentSecurityWrapper, Opaque>::singleton;
-    }
-
     // If UniversalXPConnect is enabled, this is just some dumb mochitest. Use
     // a vanilla CCW.
-    else if (xpc::IsUniversalXPConnectEnabled(target)) {
+    if (xpc::IsUniversalXPConnectEnabled(target)) {
         CrashIfNotInAutomation();
         wrapper = &CrossCompartmentWrapper::singleton;
     }
diff --git a/layout/painting/moz.build b/layout/painting/moz.build
index 508e8d95edbf..932bc6d3256b 100644
--- a/layout/painting/moz.build
+++ b/layout/painting/moz.build
@@ -15,6 +15,7 @@ EXPORTS += [
     'DisplayListClipState.h',
     'FrameLayerBuilder.h',
     'LayerState.h',
+    'nsCSSRenderingBorders.h',
     'nsDisplayItemTypes.h',
     'nsDisplayItemTypesList.h',
     'nsDisplayList.h',
diff --git a/layout/painting/nsCSSRendering.cpp b/layout/painting/nsCSSRendering.cpp
index 6f24c0f7ff54..885eb4597127 100644
--- a/layout/painting/nsCSSRendering.cpp
+++ b/layout/painting/nsCSSRendering.cpp
@@ -948,13 +948,13 @@ GetOutlineInnerRect(nsIFrame* aFrame)
   return nsRect(nsPoint(0, 0), aFrame->GetSize());
 }
 
-void
-nsCSSRendering::PaintOutline(nsPresContext* aPresContext,
-                             nsRenderingContext& aRenderingContext,
-                             nsIFrame* aForFrame,
-                             const nsRect& aDirtyRect,
-                             const nsRect& aBorderArea,
-                             nsStyleContext* aStyleContext)
+Maybe<nsCSSBorderRenderer>
+nsCSSRendering::CreateBorderRendererForOutline(nsPresContext* aPresContext,
+                                               nsRenderingContext* aRenderingContext,
+                                               nsIFrame* aForFrame,
+                                               const nsRect& aDirtyRect,
+                                               const nsRect& aBorderArea,
+                                               nsStyleContext* aStyleContext)
 {
   nscoord             twipsRadii[8];
 
@@ -968,7 +968,7 @@ nsCSSRendering::PaintOutline(nsPresContext* aPresContext,
 
   if (width == 0 && outlineStyle != NS_STYLE_BORDER_STYLE_AUTO) {
     // Empty outline
-    return;
+    return Nothing();
   }
 
   nsIFrame* bgFrame = nsCSSRendering::FindNonTransparentBackgroundFrame
@@ -997,7 +997,7 @@ nsCSSRendering::PaintOutline(nsPresContext* aPresContext,
   // encroach into the content area.  A safer calculation would be to
   // shorten insideRect by the radius one each side before performing this test.
   if (innerRect.Contains(aDirtyRect))
-    return;
+    return Nothing();
 
   nsRect outerRect = innerRect;
   outerRect.Inflate(width, width);
@@ -1022,14 +1022,14 @@ nsCSSRendering::PaintOutline(nsPresContext* aPresContext,
       nsITheme* theme = aPresContext->GetTheme();
       if (theme && theme->ThemeSupportsWidget(aPresContext, aForFrame,
                                               NS_THEME_FOCUS_OUTLINE)) {
-        theme->DrawWidgetBackground(&aRenderingContext, aForFrame,
+        theme->DrawWidgetBackground(aRenderingContext, aForFrame,
                                     NS_THEME_FOCUS_OUTLINE, innerRect,
                                     aDirtyRect);
-        return;
+        return Nothing();
       }
     }
     if (width == 0) {
-      return; // empty outline
+      return Nothing(); // empty outline
     }
     // http://dev.w3.org/csswg/css-ui/#outline
     // "User agents may treat 'auto' as 'solid'."
@@ -1061,11 +1061,10 @@ nsCSSRendering::PaintOutline(nsPresContext* aPresContext,
     document = content->OwnerDoc();
   }
 
-  // start drawing
-
+  DrawTarget* dt = aRenderingContext ? aRenderingContext->GetDrawTarget() : nullptr;
   nsCSSBorderRenderer br(aPresContext,
                          document,
-                         aRenderingContext.GetDrawTarget(),
+                         dt,
                          dirtyRect,
                          oRect,
                          outlineStyles,
@@ -1074,7 +1073,30 @@ nsCSSRendering::PaintOutline(nsPresContext* aPresContext,
                          outlineColors,
                          nullptr,
                          bgColor);
-  br.DrawBorders();
+
+  return Some(br);
+}
+
+void
+nsCSSRendering::PaintOutline(nsPresContext* aPresContext,
+                             nsRenderingContext& aRenderingContext,
+                             nsIFrame* aForFrame,
+                             const nsRect& aDirtyRect,
+                             const nsRect& aBorderArea,
+                             nsStyleContext* aStyleContext)
+{
+  Maybe<nsCSSBorderRenderer> br = CreateBorderRendererForOutline(aPresContext,
+                                                                 &aRenderingContext,
+                                                                 aForFrame,
+                                                                 aDirtyRect,
+                                                                 aBorderArea,
+                                                                 aStyleContext);
+  if (!br) {
+    return;
+  }
+
+  // start drawing
+  br->DrawBorders();
 
   PrintAsStringNewline();
 }
diff --git a/layout/painting/nsCSSRendering.h b/layout/painting/nsCSSRendering.h
index 3c8007dae08f..334b57831573 100644
--- a/layout/painting/nsCSSRendering.h
+++ b/layout/painting/nsCSSRendering.h
@@ -450,6 +450,13 @@ struct nsCSSRendering {
                                       nsStyleContext* aStyleContext,
                                       Sides aSkipSides = Sides());
 
+  static mozilla::Maybe<nsCSSBorderRenderer>
+  CreateBorderRendererForOutline(nsPresContext* aPresContext,
+                                 nsRenderingContext* aRenderingContext,
+                                 nsIFrame* aForFrame,
+                                 const nsRect& aDirtyRect,
+                                 const nsRect& aBorderArea,
+                                 nsStyleContext* aStyleContext);
 
   /**
    * Render the outline for an element using css rendering rules
diff --git a/layout/painting/nsCSSRenderingBorders.h b/layout/painting/nsCSSRenderingBorders.h
index 65a25f8e72d8..26c96b35c1ad 100644
--- a/layout/painting/nsCSSRenderingBorders.h
+++ b/layout/painting/nsCSSRenderingBorders.h
@@ -78,6 +78,7 @@ class nsCSSBorderRenderer final
   typedef mozilla::gfx::StrokeOptions StrokeOptions;
 
   friend class nsDisplayBorder;
+  friend class nsDisplayOutline;
 
 public:
 
@@ -121,7 +122,7 @@ private:
 
   // destination DrawTarget and dirty rect
   DrawTarget* mDrawTarget;
-  const Rect mDirtyRect;
+  Rect mDirtyRect;
 
   // the rectangle of the outside and the inside of the border
   Rect mOuterRect;
diff --git a/layout/painting/nsDisplayList.cpp b/layout/painting/nsDisplayList.cpp
index ab473b5ebb72..8f3fcbf9346a 100644
--- a/layout/painting/nsDisplayList.cpp
+++ b/layout/painting/nsDisplayList.cpp
@@ -85,6 +85,7 @@
 #include "mozilla/layers/WebRenderLayerManager.h"
 #include "mozilla/layers/WebRenderDisplayItemLayer.h"
 #include "mozilla/layers/WebRenderMessages.h"
+#include "mozilla/layers/WebRenderDisplayItemLayer.h"
 
 // GetCurrentTime is defined in winbase.h as zero argument macro forwarding to
 // GetTickCount().
@@ -4095,6 +4096,72 @@ nsDisplayOutline::Paint(nsDisplayListBuilder* aBuilder,
                                mFrame->StyleContext());
 }
 
+LayerState
+nsDisplayOutline::GetLayerState(nsDisplayListBuilder* aBuilder,
+                                LayerManager* aManager,
+                                const ContainerLayerParameters& aParameters)
+{
+  if (!gfxPrefs::LayersAllowOutlineLayers()) {
+    return LAYER_NONE;
+  }
+
+  uint8_t outlineStyle = mFrame->StyleContext()->StyleOutline()->mOutlineStyle;
+  if (outlineStyle == NS_STYLE_BORDER_STYLE_AUTO && nsLayoutUtils::IsOutlineStyleAutoEnabled()) {
+      nsITheme* theme = mFrame->PresContext()->GetTheme();
+      if (theme && theme->ThemeSupportsWidget(mFrame->PresContext(), mFrame,
+                                              NS_THEME_FOCUS_OUTLINE)) {
+        return LAYER_NONE;
+      }
+  }
+
+  nsPoint offset = ToReferenceFrame();
+  Maybe<nsCSSBorderRenderer> br =
+    nsCSSRendering::CreateBorderRendererForOutline(mFrame->PresContext(),
+                                                   nullptr, mFrame,
+                                                   mVisibleRect,
+                                                   nsRect(offset, mFrame->GetSize()),
+                                                   mFrame->StyleContext());
+
+  if (!br) {
+    return LAYER_NONE;
+  }
+
+  mBorderRenderer = br;
+
+  return LAYER_ACTIVE;
+}
+
+already_AddRefed<Layer>
+nsDisplayOutline::BuildLayer(nsDisplayListBuilder* aBuilder,
+                             LayerManager* aManager,
+                             const ContainerLayerParameters& aContainerParameters)
+{
+  return BuildDisplayItemLayer(aBuilder, aManager, aContainerParameters);
+}
+
+void
+nsDisplayOutline::CreateWebRenderCommands(nsTArray<WebRenderCommand>& aCommands,
+                                          WebRenderDisplayItemLayer* aLayer)
+{
+  MOZ_ASSERT(mBorderRenderer.isSome());
+
+  Rect outlineTransformedRect = aLayer->RelativeToParent(mBorderRenderer->mOuterRect);
+
+  nsCSSBorderRenderer* br = mBorderRenderer.ptr();
+  WrBorderSide side[4];
+  NS_FOR_CSS_SIDES(i) {
+    side[i] = wr::ToWrBorderSide(br->mBorderWidths[i], ToDeviceColor(br->mBorderColors[i]), br->mBorderStyles[i]);
+  }
+  WrBorderRadius borderRadius = wr::ToWrBorderRadius(LayerSize(br->mBorderRadii[0].width, br->mBorderRadii[0].height),
+                                                     LayerSize(br->mBorderRadii[1].width, br->mBorderRadii[1].height),
+                                                     LayerSize(br->mBorderRadii[3].width, br->mBorderRadii[3].height),
+                                                     LayerSize(br->mBorderRadii[2].width, br->mBorderRadii[2].height));
+  aCommands.AppendElement(OpDPPushBorder(wr::ToWrRect(outlineTransformedRect),
+                                         wr::ToWrRect(outlineTransformedRect),
+                                         side[0], side[1], side[2], side[3],
+                                         borderRadius));
+}
+
 bool
 nsDisplayOutline::IsInvisibleInRect(const nsRect& aRect)
 {
diff --git a/layout/painting/nsDisplayList.h b/layout/painting/nsDisplayList.h
index 4d7ecaffe48b..747ac90cb4a2 100644
--- a/layout/painting/nsDisplayList.h
+++ b/layout/painting/nsDisplayList.h
@@ -34,6 +34,7 @@
 #include "mozilla/UniquePtr.h"
 #include "mozilla/TimeStamp.h"
 #include "mozilla/gfx/UserData.h"
+#include "nsCSSRenderingBorders.h"
 
 #include <stdint.h>
 #include "nsTHashtable.h"
@@ -3450,10 +3451,20 @@ public:
   }
 #endif
 
+  virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
+                                   LayerManager* aManager,
+                                   const ContainerLayerParameters& aParameters) override;
+  virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
+                                             LayerManager* aManager,
+                                             const ContainerLayerParameters& aContainerParameters) override;
+  virtual void CreateWebRenderCommands(nsTArray<WebRenderCommand>& aCommands,
+                                       mozilla::layers::WebRenderDisplayItemLayer* aLayer) override;
   virtual bool IsInvisibleInRect(const nsRect& aRect) override;
   virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) override;
   virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) override;
   NS_DISPLAY_DECL_NAME("Outline", TYPE_OUTLINE)
+
+  mozilla::Maybe<nsCSSBorderRenderer> mBorderRenderer;
 };
 
 /**
diff --git a/layout/svg/nsFilterInstance.cpp b/layout/svg/nsFilterInstance.cpp
index 57599be44352..da8a559eeb46 100644
--- a/layout/svg/nsFilterInstance.cpp
+++ b/layout/svg/nsFilterInstance.cpp
@@ -264,7 +264,6 @@ nsFilterInstance::ComputeTargetBBoxInFilterSpace()
 bool
 nsFilterInstance::ComputeUserSpaceToFilterSpaceScale()
 {
-  gfxMatrix canvasTransform;
   if (mTargetFrame) {
     mUserSpaceToFilterSpaceScale = mPaintTransform.ScaleFactors(true);
     if (mUserSpaceToFilterSpaceScale.width <= 0.0f ||
@@ -279,6 +278,7 @@ nsFilterInstance::ComputeUserSpaceToFilterSpaceScale()
   mFilterSpaceToUserSpaceScale =
     gfxSize(1.0f / mUserSpaceToFilterSpaceScale.width,
             1.0f / mUserSpaceToFilterSpaceScale.height);
+
   return true;
 }
 
diff --git a/memory/replace/dmd/DMD.cpp b/memory/replace/dmd/DMD.cpp
index 49eb2797020b..4019119651a7 100644
--- a/memory/replace/dmd/DMD.cpp
+++ b/memory/replace/dmd/DMD.cpp
@@ -1546,6 +1546,22 @@ NopStackWalkCallback(uint32_t aFrameNumber, void* aPc, void* aSp,
 }
 #endif
 
+static void
+prefork()
+{
+  if (gStateLock) {
+    gStateLock->Lock();
+  }
+}
+
+static void
+postfork()
+{
+  if (gStateLock) {
+    gStateLock->Unlock();
+  }
+}
+
 // WARNING: this function runs *very* early -- before all static initializers
 // have run.  For this reason, non-scalar globals such as gStateLock and
 // gStackTraceTable are allocated dynamically (so we can guarantee their
@@ -1556,6 +1572,16 @@ Init(const malloc_table_t* aMallocTable)
   gMallocTable = aMallocTable;
   gDMDBridge = InfallibleAllocPolicy::new_<DMDBridge>();
 
+#ifndef XP_WIN
+  // Avoid deadlocks when forking by acquiring our state lock prior to forking
+  // and releasing it after forking. See |LogAlloc|'s |replace_init| for
+  // in-depth details.
+  //
+  // Note: This must run after attempting an allocation so as to give the
+  // system malloc a chance to insert its own atfork handler.
+  pthread_atfork(prefork, postfork, postfork);
+#endif
+
   // DMD is controlled by the |DMD| environment variable.
   const char* e = getenv("DMD");
 
diff --git a/mobile/android/base/java/org/mozilla/gecko/BrowserApp.java b/mobile/android/base/java/org/mozilla/gecko/BrowserApp.java
index 4abe5fd9734c..c987cc67d723 100644
--- a/mobile/android/base/java/org/mozilla/gecko/BrowserApp.java
+++ b/mobile/android/base/java/org/mozilla/gecko/BrowserApp.java
@@ -2070,8 +2070,8 @@ public class BrowserApp extends GeckoApp
                 request.setMimeType(mimeType);
 
                 try {
-                    request.setDestinationInExternalFilesDir(
-                            this, Environment.DIRECTORY_DOWNLOADS, filename);
+                    request.setDestinationInExternalPublicDir(
+                            Environment.DIRECTORY_DOWNLOADS, filename);
                 } catch (IllegalStateException e) {
                     Log.e(LOGTAG, "Cannot create download directory");
                     break;
diff --git a/mobile/android/components/HelperAppDialog.js b/mobile/android/components/HelperAppDialog.js
index be83983c8178..9769bc1fa2d6 100644
--- a/mobile/android/components/HelperAppDialog.js
+++ b/mobile/android/components/HelperAppDialog.js
@@ -137,8 +137,16 @@ HelperAppLauncherDialog.prototype = {
     }
 
     if (this._shouldForwardToAndroidDownloadManager(aLauncher)) {
-      this._downloadWithAndroidDownloadManager(aLauncher);
-      aLauncher.cancel(Cr.NS_BINDING_ABORTED);
+      Task.spawn(function* () {
+        try {
+          let hasPermission = yield RuntimePermissions.waitForPermissions(RuntimePermissions.WRITE_EXTERNAL_STORAGE);
+          if (hasPermission) {
+            this._downloadWithAndroidDownloadManager(aLauncher);
+            aLauncher.cancel(Cr.NS_BINDING_ABORTED);
+          }
+        } finally {
+        }
+      }.bind(this)).catch(Cu.reportError);
       return;
     }
 
diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/StringUtils.java b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/StringUtils.java
index e5bf6551bd23..56f782915135 100644
--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/StringUtils.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/StringUtils.java
@@ -102,20 +102,19 @@ public class StringUtils {
             return url;
         }
 
-        int start = 0;
-        int end = url.length();
+        String newURL = url;
 
-        if (url.startsWith("http://")) {
-            start = 7;
-        } else if (url.startsWith("https://") && flags == UrlFlags.STRIP_HTTPS) {
-            start = 8;
+        if (newURL.startsWith("http://")) {
+            newURL = newURL.replace("http://", "");
+        } else if (newURL.startsWith("https://") && flags == UrlFlags.STRIP_HTTPS) {
+            newURL = newURL.replace("https://", "");
         }
 
-        if (url.endsWith("/")) {
-            end--;
+        if (newURL.endsWith("/")) {
+            newURL = newURL.substring(0, newURL.length()-1);
         }
 
-        return url.substring(start, end);
+        return newURL;
     }
 
     public static boolean isHttpOrHttps(String url) {
diff --git a/modules/libpref/Preferences.cpp b/modules/libpref/Preferences.cpp
index b1f86b9e0f62..077289492076 100644
--- a/modules/libpref/Preferences.cpp
+++ b/modules/libpref/Preferences.cpp
@@ -60,11 +60,22 @@
     return NS_ERROR_NOT_AVAILABLE;                                             \
   }                                                                            \
 } while (0);
+class WatchinPrefRAII {
+public:
+  WatchinPrefRAII() {
+    pref_SetWatchingPref(true);
+  }
+  ~WatchinPrefRAII() {
+    pref_SetWatchingPref(false);
+  }
+};
+#define WATCHING_PREF_RAII() WatchinPrefRAII watchingPrefRAII
 #else
 #define ENSURE_MAIN_PROCESS(message, pref)                                     \
   if (MOZ_UNLIKELY(!XRE_IsParentProcess())) {        \
     return NS_ERROR_NOT_AVAILABLE;                                             \
   }
+#define WATCHING_PREF_RAII()
 #endif
 
 class PrefCallback;
@@ -1732,6 +1743,7 @@ Preferences::RegisterCallbackAndCall(PrefChangedFunc aCallback,
                                      void* aClosure,
                                      MatchKind aMatchKind)
 {
+  WATCHING_PREF_RAII();
   nsresult rv = RegisterCallback(aCallback, aPref, aClosure, aMatchKind);
   if (NS_SUCCEEDED(rv)) {
     (*aCallback)(aPref, aClosure);
@@ -1779,6 +1791,7 @@ Preferences::AddBoolVarCache(bool* aCache,
                              const char* aPref,
                              bool aDefault)
 {
+  WATCHING_PREF_RAII();
   NS_ASSERTION(aCache, "aCache must not be NULL");
 #ifdef DEBUG
   AssertNotAlreadyCached("bool", aPref, aCache);
@@ -1804,6 +1817,7 @@ Preferences::AddIntVarCache(int32_t* aCache,
                             const char* aPref,
                             int32_t aDefault)
 {
+  WATCHING_PREF_RAII();
   NS_ASSERTION(aCache, "aCache must not be NULL");
 #ifdef DEBUG
   AssertNotAlreadyCached("int", aPref, aCache);
@@ -1829,6 +1843,7 @@ Preferences::AddUintVarCache(uint32_t* aCache,
                              const char* aPref,
                              uint32_t aDefault)
 {
+  WATCHING_PREF_RAII();
   NS_ASSERTION(aCache, "aCache must not be NULL");
 #ifdef DEBUG
   AssertNotAlreadyCached("uint", aPref, aCache);
@@ -1856,6 +1871,7 @@ Preferences::AddAtomicUintVarCache(Atomic<uint32_t, Order>* aCache,
                                    const char* aPref,
                                    uint32_t aDefault)
 {
+  WATCHING_PREF_RAII();
   NS_ASSERTION(aCache, "aCache must not be NULL");
 #ifdef DEBUG
   AssertNotAlreadyCached("uint", aPref, aCache);
@@ -1888,6 +1904,7 @@ Preferences::AddFloatVarCache(float* aCache,
                              const char* aPref,
                              float aDefault)
 {
+  WATCHING_PREF_RAII();
   NS_ASSERTION(aCache, "aCache must not be NULL");
 #ifdef DEBUG
   AssertNotAlreadyCached("float", aPref, aCache);
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 7d976dfb1e97..fb5ba8363b59 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -1273,7 +1273,7 @@ pref("javascript.options.strict.debug",     false);
 pref("javascript.options.baselinejit",      true);
 pref("javascript.options.ion",              true);
 pref("javascript.options.asmjs",            true);
-pref("javascript.options.wasm",             false);
+pref("javascript.options.wasm",             true);
 pref("javascript.options.wasm_baselinejit", false);
 pref("javascript.options.native_regexp",    true);
 pref("javascript.options.parallel_parsing", true);
diff --git a/modules/libpref/prefapi.cpp b/modules/libpref/prefapi.cpp
index b9052c5d95dc..65d984d0f6bb 100644
--- a/modules/libpref/prefapi.cpp
+++ b/modules/libpref/prefapi.cpp
@@ -737,12 +737,21 @@ static PrefTypeFlags pref_SetValue(PrefValue* existingValue, PrefTypeFlags flags
 #ifdef DEBUG
 static pref_initPhase gPhase = START;
 
+static bool gWatchingPref = false;
+
 void
 pref_SetInitPhase(pref_initPhase phase)
 {
     gPhase = phase;
 }
 
+void
+pref_SetWatchingPref(bool watching)
+{
+    gWatchingPref = watching;
+}
+
+
 struct StringComparator
 {
     const char* mKey;
@@ -774,8 +783,13 @@ PrefHashEntry* pref_HashTableLookup(const char *key)
      * Consider moving it later or add it to the whitelist in ContentPrefs.cpp
      * and get review from a DOM peer
      */
-    MOZ_ASSERT((!XRE_IsContentProcess() || gPhase > END_INIT_PREFS || inInitArray(key)),
-               "accessing non-init pref before the rest of the prefs are sent");
+#ifdef DEBUG
+    if (XRE_IsContentProcess() && gPhase <= END_INIT_PREFS &&
+        !gWatchingPref && !inInitArray(key)) {
+      MOZ_CRASH_UNSAFE_PRINTF("accessing non-init pref %s before the rest of the prefs are sent",
+                              key);
+    }
+#endif
     return static_cast<PrefHashEntry*>(gHashTable->Search(key));
 }
 
diff --git a/modules/libpref/prefapi_private_data.h b/modules/libpref/prefapi_private_data.h
index 4cf58f6a9f85..b7c49dafe804 100644
--- a/modules/libpref/prefapi_private_data.h
+++ b/modules/libpref/prefapi_private_data.h
@@ -29,6 +29,9 @@ pref_SetPref(const mozilla::dom::PrefSetting& aPref);
 #ifdef DEBUG
 void
 pref_SetInitPhase(pref_initPhase phase);
+
+void
+pref_SetWatchingPref(bool watching);
 #endif
 
 int pref_CompareStrings(const void *v1, const void *v2, void* unused);
diff --git a/netwerk/test/unit/head_channels.js b/netwerk/test/unit/head_channels.js
index 6e37a18bc950..37c958dc811c 100644
--- a/netwerk/test/unit/head_channels.js
+++ b/netwerk/test/unit/head_channels.js
@@ -172,6 +172,7 @@ ChannelListener.prototype = {
     }
     try {
       this._closure(request, this._buffer, this._closurectx, this._isFromCache);
+      this._closurectx = null;
     } catch (ex) {
       do_throw("Error in closure function: " + ex);
     }
diff --git a/python/mozbuild/mozbuild/backend/recursivemake.py b/python/mozbuild/mozbuild/backend/recursivemake.py
index 1e46d8d72e9f..b605fd7e745b 100644
--- a/python/mozbuild/mozbuild/backend/recursivemake.py
+++ b/python/mozbuild/mozbuild/backend/recursivemake.py
@@ -1077,6 +1077,7 @@ class RecursiveMakeBackend(CommonBackend):
                                    target_variable,
                                    target_cargo_variable):
         backend_file.write_once('CARGO_FILE := %s\n' % obj.cargo_file)
+        backend_file.write_once('CARGO_TARGET_DIR := .\n')
         backend_file.write('%s += %s\n' % (target_variable, obj.location))
         backend_file.write('%s += %s\n' % (target_cargo_variable, obj.name))
 
@@ -1250,6 +1251,13 @@ class RecursiveMakeBackend(CommonBackend):
             feature_var = 'HOST_RUST_LIBRARY_FEATURES'
         backend_file.write_once('%s := %s\n' % (libdef.LIB_FILE_VAR, libdef.import_name))
         backend_file.write('CARGO_FILE := $(srcdir)/Cargo.toml\n')
+        # Need to normalize the path so Cargo sees the same paths from all
+        # possible invocations of Cargo with this CARGO_TARGET_DIR.  Otherwise,
+        # Cargo's dependency calculations don't work as we expect and we wind
+        # up recompiling lots of things.
+        target_dir = mozpath.join(backend_file.objdir, libdef.target_dir)
+        target_dir = mozpath.normpath(target_dir)
+        backend_file.write('CARGO_TARGET_DIR := %s\n' % target_dir)
         if libdef.features:
             backend_file.write('%s := %s\n' % (libdef.FEATURES_VAR, ' '.join(libdef.features)))
 
diff --git a/python/mozbuild/mozbuild/backend/test_manifest.py b/python/mozbuild/mozbuild/backend/test_manifest.py
index 4fb3b548abc9..0cfa59fb7772 100644
--- a/python/mozbuild/mozbuild/backend/test_manifest.py
+++ b/python/mozbuild/mozbuild/backend/test_manifest.py
@@ -32,6 +32,9 @@ class TestManifestBackend(PartialBackend):
 
         self.backend_input_files.add(obj.path)
         self.backend_input_files |= obj.context_all_paths
+        for source in obj.source_relpaths:
+            self.backend_input_files.add(mozpath.join(obj.topsrcdir,
+                                                      source))
         try:
             from reftest import ReftestManifest
 
diff --git a/python/mozbuild/mozbuild/frontend/context.py b/python/mozbuild/mozbuild/frontend/context.py
index 00560e85b606..0e784d835673 100644
--- a/python/mozbuild/mozbuild/frontend/context.py
+++ b/python/mozbuild/mozbuild/frontend/context.py
@@ -959,6 +959,15 @@ VARIABLES = {
         RustLibrary template instead.
         """),
 
+    'RUST_LIBRARY_TARGET_DIR': (unicode, unicode,
+        """Where CARGO_TARGET_DIR should point when compiling this library.  If
+        not set, it defaults to the current objdir.  It should be a relative path
+        to the current objdir; absolute paths should not be used.
+
+        This variable should not be used directly; you should be using the
+        RustLibrary template instead.
+        """),
+
     'HOST_RUST_LIBRARY_FEATURES': (List, list,
         """Cargo features to activate for this host library.
 
diff --git a/python/mozbuild/mozbuild/frontend/data.py b/python/mozbuild/mozbuild/frontend/data.py
index 5c5893c28d25..5b07dafdddcc 100644
--- a/python/mozbuild/mozbuild/frontend/data.py
+++ b/python/mozbuild/mozbuild/frontend/data.py
@@ -420,7 +420,7 @@ class HostSimpleProgram(HostMixin, BaseProgram):
     KIND = 'host'
 
 
-def cargo_target_directory(context, target_var):
+def cargo_output_directory(context, target_var):
     # cargo creates several directories and places its build artifacts
     # in those directories.  The directory structure depends not only
     # on the target, but also what sort of build we are doing.
@@ -446,7 +446,7 @@ class BaseRustProgram(ContextDerived):
         ContextDerived.__init__(self, context)
         self.name = name
         self.cargo_file = cargo_file
-        cargo_dir = cargo_target_directory(context, self.TARGET_SUBST_VAR)
+        cargo_dir = cargo_output_directory(context, self.TARGET_SUBST_VAR)
         exe_file = '%s%s' % (name, context.config.substs.get(self.SUFFIX_VAR, ''))
         self.location = mozpath.join(cargo_dir, exe_file)
 
@@ -523,13 +523,14 @@ class RustLibrary(StaticLibrary):
         'dependencies',
         'deps_path',
         'features',
+        'target_dir',
     )
     TARGET_SUBST_VAR = 'RUST_TARGET'
     FEATURES_VAR = 'RUST_LIBRARY_FEATURES'
     LIB_FILE_VAR = 'RUST_LIBRARY_FILE'
 
     def __init__(self, context, basename, cargo_file, crate_type, dependencies,
-                 features, **args):
+                 features, target_dir, **args):
         StaticLibrary.__init__(self, context, basename, **args)
         self.cargo_file = cargo_file
         self.crate_type = crate_type
@@ -542,10 +543,12 @@ class RustLibrary(StaticLibrary):
                                      basename.replace('-', '_'),
                                      context.config.lib_suffix)
         self.dependencies = dependencies
-        build_dir = cargo_target_directory(context, self.TARGET_SUBST_VAR)
+        build_dir = mozpath.join(target_dir,
+                                 cargo_output_directory(context, self.TARGET_SUBST_VAR))
         self.import_name = mozpath.join(build_dir, self.lib_name)
         self.deps_path = mozpath.join(build_dir, 'deps')
         self.features = features
+        self.target_dir = target_dir
 
 
 class SharedLibrary(Library):
diff --git a/python/mozbuild/mozbuild/frontend/emitter.py b/python/mozbuild/mozbuild/frontend/emitter.py
index d518bd20a32c..8de24fd8ee45 100644
--- a/python/mozbuild/mozbuild/frontend/emitter.py
+++ b/python/mozbuild/mozbuild/frontend/emitter.py
@@ -465,6 +465,36 @@ class TreeMetadataEmitter(LoggingMixin):
                      ' in [profile.%s] section') % (libname, profile_name),
                     context)
 
+            # gkrust and gkrust-gtest must have the exact same profile settings
+            # for our almost-workspaces configuration to work properly.
+            if libname in ('gkrust', 'gkrust-gtest'):
+                if profile_name == 'dev':
+                    expected_profile = {
+                        'opt-level': 1,
+                        'debug': True,
+                        'rpath': False,
+                        'lto': False,
+                        'debug-assertions': True,
+                        'codegen-units': 1,
+                        'panic': 'abort',
+                    }
+                else:
+                    expected_profile = {
+                        'opt-level': 2,
+                        'debug': True,
+                        'rpath': False,
+                        'lto': True,
+                        'debug-assertions': False,
+                        'panic': 'abort',
+                    }
+
+                if profile != expected_profile:
+                    raise SandboxValidationError(
+                        'Cargo profile.%s for %s is incorrect' % (profile_name, libname),
+                        context)
+
+        cargo_target_dir = context.get('RUST_LIBRARY_TARGET_DIR', '.')
+
         dependencies = set(config.get('dependencies', {}).iterkeys())
 
         features = context.get(cls.FEATURES_VAR, [])
@@ -475,7 +505,7 @@ class TreeMetadataEmitter(LoggingMixin):
                 context)
 
         return cls(context, libname, cargo_file, crate_type, dependencies,
-                   features, **static_args)
+                   features, cargo_target_dir, **static_args)
 
 
     def _handle_linkables(self, context, passthru, generated_files):
diff --git a/python/mozbuild/mozbuild/test/backend/data/rust-library-features/Cargo.toml b/python/mozbuild/mozbuild/test/backend/data/rust-library-features/Cargo.toml
index cbaeaecec8fb..756ab433420f 100644
--- a/python/mozbuild/mozbuild/test/backend/data/rust-library-features/Cargo.toml
+++ b/python/mozbuild/mozbuild/test/backend/data/rust-library-features/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "gkrust"
+name = "feature-library"
 version = "0.1.0"
 authors = [
   "Nobody <nobody@mozilla.org>",
diff --git a/python/mozbuild/mozbuild/test/backend/data/rust-library-features/moz.build b/python/mozbuild/mozbuild/test/backend/data/rust-library-features/moz.build
index 5efbe4d3763d..3394fdd4e39a 100644
--- a/python/mozbuild/mozbuild/test/backend/data/rust-library-features/moz.build
+++ b/python/mozbuild/mozbuild/test/backend/data/rust-library-features/moz.build
@@ -16,4 +16,4 @@ def RustLibrary(name, features):
     RUST_LIBRARY_FEATURES = features
 
 
-RustLibrary('gkrust', ['musthave', 'cantlivewithout'])
+RustLibrary('feature-library', ['musthave', 'cantlivewithout'])
diff --git a/python/mozbuild/mozbuild/test/backend/data/rust-library/Cargo.toml b/python/mozbuild/mozbuild/test/backend/data/rust-library/Cargo.toml
index cbaeaecec8fb..bde9b929d997 100644
--- a/python/mozbuild/mozbuild/test/backend/data/rust-library/Cargo.toml
+++ b/python/mozbuild/mozbuild/test/backend/data/rust-library/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "gkrust"
+name = "test-library"
 version = "0.1.0"
 authors = [
   "Nobody <nobody@mozilla.org>",
diff --git a/python/mozbuild/mozbuild/test/backend/data/rust-library/moz.build b/python/mozbuild/mozbuild/test/backend/data/rust-library/moz.build
index ec2c83d60393..970b6b4be5df 100644
--- a/python/mozbuild/mozbuild/test/backend/data/rust-library/moz.build
+++ b/python/mozbuild/mozbuild/test/backend/data/rust-library/moz.build
@@ -15,4 +15,4 @@ def RustLibrary(name):
     IS_RUST_LIBRARY = True
 
 
-RustLibrary('gkrust')
+RustLibrary('test-library')
diff --git a/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/mochitest-common.ini b/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/mochitest-common.ini
new file mode 100644
index 000000000000..31d07b5af338
--- /dev/null
+++ b/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/mochitest-common.ini
@@ -0,0 +1 @@
+[test_bar.js]
diff --git a/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/mochitest.ini b/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/mochitest.ini
new file mode 100644
index 000000000000..cf7a3c44bd42
--- /dev/null
+++ b/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/mochitest.ini
@@ -0,0 +1,2 @@
+[test_foo.js]
+[include:mochitest-common.ini]
diff --git a/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/moz.build b/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/moz.build
new file mode 100644
index 000000000000..d4003d0e0170
--- /dev/null
+++ b/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/moz.build
@@ -0,0 +1,6 @@
+# Any copyright is dedicated to the Public Domain.
+# http://creativecommons.org/publicdomain/zero/1.0/
+
+MOCHITEST_MANIFESTS += [
+    'mochitest.ini',
+]
diff --git a/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/test_bar.js b/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/test_bar.js
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/test_foo.js b/python/mozbuild/mozbuild/test/backend/data/test-manifests-backend-sources/test_foo.js
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/python/mozbuild/mozbuild/test/backend/test_recursivemake.py b/python/mozbuild/mozbuild/test/backend/test_recursivemake.py
index eacad57ef7d0..d4fc1b87763b 100644
--- a/python/mozbuild/mozbuild/test/backend/test_recursivemake.py
+++ b/python/mozbuild/mozbuild/test/backend/test_recursivemake.py
@@ -762,8 +762,9 @@ class TestRecursiveMakeBackend(BackendTester):
         lines = [l.strip() for l in open(backend_path, 'rt').readlines()[2:]]
 
         expected = [
-            'RUST_LIBRARY_FILE := x86_64-unknown-linux-gnu/release/libgkrust.a',
+            'RUST_LIBRARY_FILE := ./x86_64-unknown-linux-gnu/release/libtest_library.a',
             'CARGO_FILE := $(srcdir)/Cargo.toml',
+            'CARGO_TARGET_DIR := %s' % env.topobjdir,
         ]
 
         self.assertEqual(lines, expected)
@@ -776,8 +777,9 @@ class TestRecursiveMakeBackend(BackendTester):
         lines = [l.strip() for l in open(backend_path, 'rt').readlines()[2:]]
 
         expected = [
-            'HOST_RUST_LIBRARY_FILE := x86_64-unknown-linux-gnu/release/libhostrusttool.a',
+            'HOST_RUST_LIBRARY_FILE := ./x86_64-unknown-linux-gnu/release/libhostrusttool.a',
             'CARGO_FILE := $(srcdir)/Cargo.toml',
+            'CARGO_TARGET_DIR := %s' % env.topobjdir,
         ]
 
         self.assertEqual(lines, expected)
@@ -790,8 +792,9 @@ class TestRecursiveMakeBackend(BackendTester):
         lines = [l.strip() for l in open(backend_path, 'rt').readlines()[2:]]
 
         expected = [
-            'HOST_RUST_LIBRARY_FILE := x86_64-unknown-linux-gnu/release/libhostrusttool.a',
+            'HOST_RUST_LIBRARY_FILE := ./x86_64-unknown-linux-gnu/release/libhostrusttool.a',
             'CARGO_FILE := $(srcdir)/Cargo.toml',
+            'CARGO_TARGET_DIR := %s' % env.topobjdir,
             'HOST_RUST_LIBRARY_FEATURES := musthave cantlivewithout',
         ]
 
@@ -805,8 +808,9 @@ class TestRecursiveMakeBackend(BackendTester):
         lines = [l.strip() for l in open(backend_path, 'rt').readlines()[2:]]
 
         expected = [
-            'RUST_LIBRARY_FILE := x86_64-unknown-linux-gnu/release/libgkrust.a',
+            'RUST_LIBRARY_FILE := ./x86_64-unknown-linux-gnu/release/libfeature_library.a',
             'CARGO_FILE := $(srcdir)/Cargo.toml',
+            'CARGO_TARGET_DIR := %s' % env.topobjdir,
             'RUST_LIBRARY_FEATURES := musthave cantlivewithout',
         ]
 
@@ -821,6 +825,7 @@ class TestRecursiveMakeBackend(BackendTester):
 
         expected = [
             'CARGO_FILE := %s/code/Cargo.toml' % env.topsrcdir,
+            'CARGO_TARGET_DIR := .',
             'RUST_PROGRAMS += i686-pc-windows-msvc/release/target.exe',
             'RUST_CARGO_PROGRAMS += target',
             'HOST_RUST_PROGRAMS += i686-pc-windows-msvc/release/host.exe',
diff --git a/python/mozbuild/mozbuild/test/backend/test_test_manifest.py b/python/mozbuild/mozbuild/test/backend/test_test_manifest.py
index 9bb93db855e3..250eb401d80a 100644
--- a/python/mozbuild/mozbuild/test/backend/test_test_manifest.py
+++ b/python/mozbuild/mozbuild/test/backend/test_test_manifest.py
@@ -68,6 +68,24 @@ class TestTestManifestBackend(BackendTester):
         self.assertIn('here', o[manifest_path])
         self.assertIn('support-files', o[manifest_path])
 
+    def test_test_manifest_sources(self):
+        """Ensure that backend sources are generated correctly."""
+        env = self._consume('test-manifests-backend-sources', TestManifestBackend)
+
+        backend_path = mozpath.join(env.topobjdir, 'backend.TestManifestBackend.in')
+        self.assertTrue(os.path.exists(backend_path))
+
+        status_path = mozpath.join(env.topobjdir, 'config.status')
+
+        with open(backend_path, 'r') as fh:
+            sources = set(source.strip() for source in fh)
+
+        self.assertEquals(sources,
+                          set([mozpath.join(env.topsrcdir, 'mochitest.ini'),
+                               mozpath.join(env.topsrcdir, 'mochitest-common.ini'),
+                               mozpath.join(env.topsrcdir, 'moz.build'),
+                               status_path]))
+
 
 if __name__ == '__main__':
     main()
diff --git a/security/apps/AppSignatureVerification.cpp b/security/apps/AppSignatureVerification.cpp
index bd2d13dc6149..daef5a7ac499 100644
--- a/security/apps/AppSignatureVerification.cpp
+++ b/security/apps/AppSignatureVerification.cpp
@@ -864,9 +864,13 @@ OpenSignedAppFile(AppTrustedRoot aTrustedRoot, nsIFile* aJarFile,
   // Return the signer's certificate to the reader if they want it.
   // XXX: We should return an nsIX509CertList with the whole validated chain.
   if (aSignerCert) {
-    MOZ_ASSERT(CERT_LIST_HEAD(builtChain));
+    CERTCertListNode* signerCertNode = CERT_LIST_HEAD(builtChain);
+    if (!signerCertNode || CERT_LIST_END(signerCertNode, builtChain) ||
+        !signerCertNode->cert) {
+      return NS_ERROR_FAILURE;
+    }
     nsCOMPtr<nsIX509Cert> signerCert =
-      nsNSSCertificate::Create(CERT_LIST_HEAD(builtChain)->cert);
+      nsNSSCertificate::Create(signerCertNode->cert);
     NS_ENSURE_TRUE(signerCert, NS_ERROR_OUT_OF_MEMORY);
     signerCert.forget(aSignerCert);
   }
@@ -938,9 +942,13 @@ VerifySignedManifest(AppTrustedRoot aTrustedRoot,
 
   // Return the signer's certificate to the reader if they want it.
   if (aSignerCert) {
-    MOZ_ASSERT(CERT_LIST_HEAD(builtChain));
+    CERTCertListNode* signerCertNode = CERT_LIST_HEAD(builtChain);
+    if (!signerCertNode || CERT_LIST_END(signerCertNode, builtChain) ||
+        !signerCertNode->cert) {
+      return NS_ERROR_FAILURE;
+    }
     nsCOMPtr<nsIX509Cert> signerCert =
-      nsNSSCertificate::Create(CERT_LIST_HEAD(builtChain)->cert);
+      nsNSSCertificate::Create(signerCertNode->cert);
     if (NS_WARN_IF(!signerCert)) {
       return NS_ERROR_OUT_OF_MEMORY;
     }
@@ -1491,9 +1499,13 @@ VerifySignedDirectory(AppTrustedRoot aTrustedRoot,
   // Return the signer's certificate to the reader if they want it.
   // XXX: We should return an nsIX509CertList with the whole validated chain.
   if (aSignerCert) {
-    MOZ_ASSERT(CERT_LIST_HEAD(builtChain));
+    CERTCertListNode* signerCertNode = CERT_LIST_HEAD(builtChain);
+    if (!signerCertNode || CERT_LIST_END(signerCertNode, builtChain) ||
+        !signerCertNode->cert) {
+      return NS_ERROR_FAILURE;
+    }
     nsCOMPtr<nsIX509Cert> signerCert =
-      nsNSSCertificate::Create(CERT_LIST_HEAD(builtChain)->cert);
+      nsNSSCertificate::Create(signerCertNode->cert);
     NS_ENSURE_TRUE(signerCert, NS_ERROR_OUT_OF_MEMORY);
     signerCert.forget(aSignerCert);
   }
diff --git a/security/certverifier/CertVerifier.cpp b/security/certverifier/CertVerifier.cpp
index 87bbefa5cafb..8d5cc05d3c7f 100644
--- a/security/certverifier/CertVerifier.cpp
+++ b/security/certverifier/CertVerifier.cpp
@@ -286,12 +286,13 @@ CertVerifier::VerifyCertificateTransparencyPolicy(
   }
 
   CERTCertListNode* endEntityNode = CERT_LIST_HEAD(builtChain);
-  if (!endEntityNode) {
+  if (!endEntityNode || CERT_LIST_END(endEntityNode, builtChain)) {
     return Result::FATAL_ERROR_INVALID_ARGS;
   }
   CERTCertListNode* issuerNode = CERT_LIST_NEXT(endEntityNode);
-  if (!issuerNode) {
+  if (!issuerNode || CERT_LIST_END(issuerNode, builtChain)) {
     // Issuer certificate is required for SCT verification.
+    // TODO(bug 1294580): change this to Result::FATAL_ERROR_INVALID_ARGS
     return Success;
   }
 
diff --git a/security/manager/ssl/ContentSignatureVerifier.cpp b/security/manager/ssl/ContentSignatureVerifier.cpp
index 8ceaff5760e8..129bb153946b 100644
--- a/security/manager/ssl/ContentSignatureVerifier.cpp
+++ b/security/manager/ssl/ContentSignatureVerifier.cpp
@@ -158,7 +158,7 @@ ContentSignatureVerifier::CreateContextInternal(const nsACString& aData,
   }
 
   CERTCertListNode* node = CERT_LIST_HEAD(certCertList.get());
-  if (!node || !node->cert) {
+  if (!node || CERT_LIST_END(node, certCertList.get()) || !node->cert) {
     return NS_ERROR_FAILURE;
   }
 
diff --git a/security/manager/ssl/SSLServerCertVerification.cpp b/security/manager/ssl/SSLServerCertVerification.cpp
index 419cab4086fb..71c112472804 100644
--- a/security/manager/ssl/SSLServerCertVerification.cpp
+++ b/security/manager/ssl/SSLServerCertVerification.cpp
@@ -1190,12 +1190,12 @@ void
 GatherEndEntityTelemetry(const UniqueCERTCertList& certList)
 {
   CERTCertListNode* endEntityNode = CERT_LIST_HEAD(certList);
-  MOZ_ASSERT(endEntityNode);
-  if (!endEntityNode) {
+  MOZ_ASSERT(endEntityNode && !CERT_LIST_END(endEntityNode, certList));
+  if (!endEntityNode || CERT_LIST_END(endEntityNode, certList)) {
     return;
   }
 
-  CERTCertificate * endEntityCert = endEntityNode->cert;
+  CERTCertificate* endEntityCert = endEntityNode->cert;
   MOZ_ASSERT(endEntityCert);
   if (!endEntityCert) {
     return;
diff --git a/security/manager/ssl/tests/unit/test_cert_trust.js b/security/manager/ssl/tests/unit/test_cert_trust.js
index 21f93080a6c9..e33dae0234ce 100644
--- a/security/manager/ssl/tests/unit/test_cert_trust.js
+++ b/security/manager/ssl/tests/unit/test_cert_trust.js
@@ -204,4 +204,14 @@ function run_test() {
 
   setup_basic_trusts(ca_cert, int_cert);
   test_ca_distrust(ee_cert, int_cert, false);
+
+  // Reset trust to default ("inherit trust")
+  setCertTrust(ca_cert, ",,");
+  setCertTrust(int_cert, ",,");
+
+  // It turns out that if an end-entity certificate is manually trusted, it can
+  // be the root of its own verified chain. This will be removed in bug 1294580.
+  setCertTrust(ee_cert, "C,,");
+  checkCertErrorGeneric(certdb, ee_cert, PRErrorCodeSuccess,
+                        certificateUsageSSLServer);
 }
diff --git a/startupcache/moz.build b/startupcache/moz.build
index 24068cb7e800..e3d88e417a54 100644
--- a/startupcache/moz.build
+++ b/startupcache/moz.build
@@ -4,6 +4,9 @@
 # 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/.
 
+with Files("**"):
+    BUG_COMPONENT = ("Core", "XPCOM")
+
 if not CONFIG['MOZ_B2G']:
     TEST_DIRS += ['test']
 
diff --git a/storage/moz.build b/storage/moz.build
index 8863105c9d5c..f42c3e47061b 100644
--- a/storage/moz.build
+++ b/storage/moz.build
@@ -4,6 +4,9 @@
 # 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/.
 
+with Files("**"):
+    BUG_COMPONENT = ("Toolkit", "Storage")
+
 DIRS += ['build']
 
 TEST_DIRS += ['test']
diff --git a/testing/mochitest/BrowserTestUtils/BrowserTestUtils.jsm b/testing/mochitest/BrowserTestUtils/BrowserTestUtils.jsm
index ab50db1c639b..48eae9c9c104 100644
--- a/testing/mochitest/BrowserTestUtils/BrowserTestUtils.jsm
+++ b/testing/mochitest/BrowserTestUtils/BrowserTestUtils.jsm
@@ -183,6 +183,13 @@ this.BrowserTestUtils = {
    * @resolves When a load event is triggered for the browser.
    */
   browserLoaded(browser, includeSubFrames=false, wantLoad=null) {
+    // If browser belongs to tabbrowser-tab, ensure it has been
+    // inserted into the document.
+    let tabbrowser = browser.ownerGlobal.gBrowser;
+    if (tabbrowser && tabbrowser.getTabForBrowser) {
+      tabbrowser._insertBrowser(tabbrowser.getTabForBrowser(browser));
+    }
+
     function isWanted(url) {
       if (!wantLoad) {
         return true;
diff --git a/testing/web-platform/meta/MANIFEST.json b/testing/web-platform/meta/MANIFEST.json
index 8741ee781b29..e542ef445c40 100644
--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -43419,6 +43419,16 @@
      {}
     ]
    ],
+   "fetch/api/policies/nested-policy.js": [
+    [
+     {}
+    ]
+   ],
+   "fetch/api/policies/nested-policy.js.headers": [
+    [
+     {}
+    ]
+   ],
    "fetch/api/policies/referrer-no-referrer.html.headers": [
     [
      {}
@@ -80855,6 +80865,12 @@
      {}
     ]
    ],
+   "XMLHttpRequest/open-url-redirected-worker-origin.htm": [
+    [
+     "/XMLHttpRequest/open-url-redirected-worker-origin.htm",
+     {}
+    ]
+   ],
    "XMLHttpRequest/open-url-worker-origin.htm": [
     [
      "/XMLHttpRequest/open-url-worker-origin.htm",
@@ -87093,6 +87109,18 @@
      {}
     ]
    ],
+   "fetch/api/basic/request-referrer-redirected-worker.html": [
+    [
+     "/fetch/api/basic/request-referrer-redirected-worker.html",
+     {}
+    ]
+   ],
+   "fetch/api/basic/request-referrer-worker.html": [
+    [
+     "/fetch/api/basic/request-referrer-worker.html",
+     {}
+    ]
+   ],
    "fetch/api/basic/request-referrer.html": [
     [
      "/fetch/api/basic/request-referrer.html",
@@ -87445,6 +87473,12 @@
      {}
     ]
    ],
+   "fetch/api/policies/referrer-no-referrer-service-worker.https.html": [
+    [
+     "/fetch/api/policies/referrer-no-referrer-service-worker.https.html",
+     {}
+    ]
+   ],
    "fetch/api/policies/referrer-no-referrer-worker.html": [
     [
      "/fetch/api/policies/referrer-no-referrer-worker.html",
@@ -87457,6 +87491,18 @@
      {}
     ]
    ],
+   "fetch/api/policies/referrer-origin-service-worker.https.html": [
+    [
+     "/fetch/api/policies/referrer-origin-service-worker.https.html",
+     {}
+    ]
+   ],
+   "fetch/api/policies/referrer-origin-when-cross-origin-service-worker.https.html": [
+    [
+     "/fetch/api/policies/referrer-origin-when-cross-origin-service-worker.https.html",
+     {}
+    ]
+   ],
    "fetch/api/policies/referrer-origin-when-cross-origin-worker.html": [
     [
      "/fetch/api/policies/referrer-origin-when-cross-origin-worker.html",
@@ -87481,6 +87527,12 @@
      {}
     ]
    ],
+   "fetch/api/policies/referrer-unsafe-url-service-worker.https.html": [
+    [
+     "/fetch/api/policies/referrer-unsafe-url-service-worker.https.html",
+     {}
+    ]
+   ],
    "fetch/api/policies/referrer-unsafe-url-worker.html": [
     [
      "/fetch/api/policies/referrer-unsafe-url-worker.html",
@@ -136404,6 +136456,10 @@
    "28603b8d225367ba648bb9271dec5cb3da73d733",
    "testharness"
   ],
+  "XMLHttpRequest/open-url-redirected-worker-origin.htm": [
+   "98c20df1cd8c7e27a94ba55f7c94d19244d7ff59",
+   "testharness"
+  ],
   "XMLHttpRequest/open-url-worker-origin.htm": [
    "e4db65c7c0a98d7f5aa84eac01705259f377f44b",
    "testharness"
@@ -163308,12 +163364,20 @@
    "6a15c64c072f4e57470ed3f2709e43fa2f806b79",
    "support"
   ],
+  "fetch/api/basic/request-referrer-redirected-worker.html": [
+   "41013925a84ab080c9c9f3b16ef4d8fdd1d50588",
+   "testharness"
+  ],
+  "fetch/api/basic/request-referrer-worker.html": [
+   "3dad9617d76eed94d8b759d0d27b20c431873dd4",
+   "testharness"
+  ],
   "fetch/api/basic/request-referrer.html": [
    "acf1ca37cf3904eccf4c7a9248c49e68f6260866",
    "testharness"
   ],
   "fetch/api/basic/request-referrer.js": [
-   "5267f72887c4f7b039d2a5aae3519dc54cceca97",
+   "03c8ccec8ee4b37994bf38f20ff9fd531a209974",
    "support"
   ],
   "fetch/api/basic/request-upload-worker.html": [
@@ -163644,6 +163708,18 @@
    "94dc6f63015b0835eb2a8c1892636bafeb1dfee7",
    "support"
   ],
+  "fetch/api/policies/nested-policy.js": [
+   "57cfc2060102695b601209e4927861aaee377c4e",
+   "support"
+  ],
+  "fetch/api/policies/nested-policy.js.headers": [
+   "fab90d344cbb78bad6445288c418b87736a830ae",
+   "support"
+  ],
+  "fetch/api/policies/referrer-no-referrer-service-worker.https.html": [
+   "274797274e05e467499b98179dd23a19a960a014",
+   "testharness"
+  ],
   "fetch/api/policies/referrer-no-referrer-worker.html": [
    "cc9274c1b182a487dbe945e6d8754a671d78e3c4",
    "testharness"
@@ -163664,6 +163740,14 @@
    "fab90d344cbb78bad6445288c418b87736a830ae",
    "support"
   ],
+  "fetch/api/policies/referrer-origin-service-worker.https.html": [
+   "cf400b001e381251b0eaca8290e975dc27f6ff0f",
+   "testharness"
+  ],
+  "fetch/api/policies/referrer-origin-when-cross-origin-service-worker.https.html": [
+   "c2d6e3abb2b4ec0342ac9c16c468adb8b03e0426",
+   "testharness"
+  ],
   "fetch/api/policies/referrer-origin-when-cross-origin-worker.html": [
    "3242db3a9319923287f36987f6f14581c239ced2",
    "testharness"
@@ -163677,7 +163761,7 @@
    "support"
   ],
   "fetch/api/policies/referrer-origin-when-cross-origin.js": [
-   "e750c643dda40176e230d39e38057d4d2bda4fcf",
+   "802ebd6d423099439a790c3db9b7ae37cbe5d9a0",
    "support"
   ],
   "fetch/api/policies/referrer-origin-when-cross-origin.js.headers": [
@@ -163689,7 +163773,7 @@
    "testharness"
   ],
   "fetch/api/policies/referrer-origin.html": [
-   "0ab191b8e4c349d47569a8d7cfeebec89711a0cb",
+   "ae8bfdfb5b9ae86522378ec798908b7db442797d",
    "testharness"
   ],
   "fetch/api/policies/referrer-origin.html.headers": [
@@ -163697,13 +163781,17 @@
    "support"
   ],
   "fetch/api/policies/referrer-origin.js": [
-   "368af4830da8fcd341ffb513b8c6c2c2bcfab3d9",
+   "e863bed9479b1b89cb0d8fae680e471ca66c757f",
    "support"
   ],
   "fetch/api/policies/referrer-origin.js.headers": [
    "56b5f91097bb278ebc69345c0b56c65eb16cc3db",
    "support"
   ],
+  "fetch/api/policies/referrer-unsafe-url-service-worker.https.html": [
+   "d2fa5c7813f57909228b51417df0267cd7ec0c20",
+   "testharness"
+  ],
   "fetch/api/policies/referrer-unsafe-url-worker.html": [
    "70e7ec27a61ee68fb419213be149816ed618ce24",
    "testharness"
@@ -163717,7 +163805,7 @@
    "support"
   ],
   "fetch/api/policies/referrer-unsafe-url.js": [
-   "24d042ef4e85cccf3d178f701af5664c954deaf3",
+   "e1881c5f3f0a7d1705a5d2eb5d3381d8788374d8",
    "support"
   ],
   "fetch/api/policies/referrer-unsafe-url.js.headers": [
diff --git a/testing/web-platform/meta/fetch/api/policies/referrer-origin-service-worker.https.html.ini b/testing/web-platform/meta/fetch/api/policies/referrer-origin-service-worker.https.html.ini
new file mode 100644
index 000000000000..8df1d2a23318
--- /dev/null
+++ b/testing/web-platform/meta/fetch/api/policies/referrer-origin-service-worker.https.html.ini
@@ -0,0 +1,5 @@
+[referrer-origin-service-worker.https.html]
+  type: testharness
+  [Cross-origin referrer is overridden by client origin]
+    expected: FAIL
+    bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1341223
diff --git a/testing/web-platform/tests/XMLHttpRequest/open-url-redirected-worker-origin.htm b/testing/web-platform/tests/XMLHttpRequest/open-url-redirected-worker-origin.htm
new file mode 100644
index 000000000000..86cba0ccb5fc
--- /dev/null
+++ b/testing/web-platform/tests/XMLHttpRequest/open-url-redirected-worker-origin.htm
@@ -0,0 +1,44 @@
+ <!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8" />
+    <title>XMLHttpRequest: redirected worker scripts, origin and referrer</title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+    <link rel="help" href="https://xhr.spec.whatwg.org/#the-open()-method" data-tested-assertations="following::OL[1]/LI[3] following::OL[1]/LI[3]/ol[1]/li[1] following::OL[1]/LI[3]/ol[1]/li[2] following::OL[1]/LI[3]/ol[1]/li[3]" />
+</head>
+<body>
+    <div id="log"></div>
+    <script type="text/javascript">
+        var test = async_test() // This "test" does not actually do any assertations. It's just there to have multiple, separate, asyncronous sub-tests.
+        var expectations = {
+            'Referer header': 'referer: '+(location.href.replace(/[^/]*$/, ''))+"resources/workerxhr-origin-referrer.js\n",
+            'Origin header': 'origin: '+location.protocol+'//'+location.hostname+((location.port === "")?"":":"+location.port)+'\n',
+            'Request URL test' : (location.href.replace(/[^/]*$/, ''))+'resources/requri.py?full'
+        }
+        // now start the worker
+        var finalWorkerURL = "workerxhr-origin-referrer.js";
+        var url = "resources/redirect.py?location=" + encodeURIComponent(finalWorkerURL);
+        var worker = new Worker(url, true)
+        worker.onmessage = function (e) {
+            var subtest = async_test(e.data.test)
+            subtest.step(function(){
+                var thisExpectation = expectations[e.data.test]
+                delete expectations[e.data.test]
+                assert_equals(e.data.result, thisExpectation)
+                subtest.done()
+            })
+            var allDone = true
+            for(var prop in expectations){
+                  allDone = false
+            }
+            if(allDone){
+                test.step(function(){
+                    test.done()
+                })
+            }
+        }
+
+    </script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/fetch/api/basic/request-referrer-redirected-worker.html b/testing/web-platform/tests/fetch/api/basic/request-referrer-redirected-worker.html
new file mode 100644
index 000000000000..0306c8770c6d
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/basic/request-referrer-redirected-worker.html
@@ -0,0 +1,17 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title>Fetch in worker: referrer header</title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+  </head>
+  <body>
+    <script>
+      let finalURL = "/fetch/api/basic/request-referrer.js";
+      let url = "/fetch/api/resources/redirect.py?location=" +
+                encodeURIComponent(finalURL);
+      fetch_tests_from_worker(new Worker(url));
+    </script>
+  </body>
+</html>
diff --git a/testing/web-platform/tests/fetch/api/basic/request-referrer-worker.html b/testing/web-platform/tests/fetch/api/basic/request-referrer-worker.html
new file mode 100644
index 000000000000..d598c8bad584
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/basic/request-referrer-worker.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title>Fetch in worker: referrer header</title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+  </head>
+  <body>
+    <script>
+      fetch_tests_from_worker(new Worker("request-referrer.js"));
+    </script>
+  </body>
+</html>
diff --git a/testing/web-platform/tests/fetch/api/basic/request-referrer.js b/testing/web-platform/tests/fetch/api/basic/request-referrer.js
index cc5cc8e01d40..6a55c6179e1b 100644
--- a/testing/web-platform/tests/fetch/api/basic/request-referrer.js
+++ b/testing/web-platform/tests/fetch/api/basic/request-referrer.js
@@ -3,7 +3,7 @@ if (this.document === undefined) {
   importScripts("../resources/utils.js");
 }
 
-function testReferrer(referrer, expected) {
+function testReferrer(referrer, expected, desc) {
   promise_test(function(test) {
     var url = RESOURCES_DIR + "inspect-headers.py?headers=referer"
     var req = new Request(url, { referrer: referrer });
@@ -17,12 +17,12 @@ function testReferrer(referrer, expected) {
         assert_equals(actual, "", "request's referer should be empty");
       }
     });
-  });
+  }, desc);
 }
 
-testReferrer("about:client", window.location.href);
+testReferrer("about:client", self.location.href, 'about:client referrer');
 
-var fooURL = new URL("./foo", window.location).href;
-testReferrer(fooURL, fooURL);
+var fooURL = new URL("./foo", self.location).href;
+testReferrer(fooURL, fooURL, 'url referrer');
 
 done();
diff --git a/testing/web-platform/tests/fetch/api/policies/nested-policy.js b/testing/web-platform/tests/fetch/api/policies/nested-policy.js
new file mode 100644
index 000000000000..b0d17696c337
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/policies/nested-policy.js
@@ -0,0 +1 @@
+// empty, but referrer-policy set on this file
diff --git a/testing/web-platform/tests/fetch/api/policies/nested-policy.js.headers b/testing/web-platform/tests/fetch/api/policies/nested-policy.js.headers
new file mode 100644
index 000000000000..7ffbf17d6be5
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/policies/nested-policy.js.headers
@@ -0,0 +1 @@
+Referrer-Policy: no-referrer
diff --git a/testing/web-platform/tests/fetch/api/policies/referrer-no-referrer-service-worker.https.html b/testing/web-platform/tests/fetch/api/policies/referrer-no-referrer-service-worker.https.html
new file mode 100644
index 000000000000..0d30ef9e3850
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/policies/referrer-no-referrer-service-worker.https.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title>Fetch in service worker: referrer with no-referrer policy</title>
+    <meta name="help" href="https://fetch.spec.whatwg.org/#main-fetch">
+    <meta name="help" href="https://fetch.spec.whatwg.org/#http-network-or-cache-fetch">
+    <meta name="author" title="Canon Research France" href="https://www.crf.canon.fr">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+    <script src="/service-workers/service-worker/resources/test-helpers.sub.js"></script>
+  </head>
+  <body>
+    <script>
+      service_worker_test("referrer-no-referrer.js?pipe=sub");
+    </script>
+  </body>
+</html>
diff --git a/testing/web-platform/tests/fetch/api/policies/referrer-origin-service-worker.https.html b/testing/web-platform/tests/fetch/api/policies/referrer-origin-service-worker.https.html
new file mode 100644
index 000000000000..4018b837816e
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/policies/referrer-origin-service-worker.https.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title>Fetch in service worker: referrer with no-referrer policy</title>
+    <meta name="help" href="https://fetch.spec.whatwg.org/#main-fetch">
+    <meta name="help" href="https://fetch.spec.whatwg.org/#http-network-or-cache-fetch">
+    <meta name="author" title="Canon Research France" href="https://www.crf.canon.fr">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+    <script src="/service-workers/service-worker/resources/test-helpers.sub.js"></script>
+  </head>
+  <body>
+    <script>
+      service_worker_test("referrer-origin.js?pipe=sub");
+    </script>
+  </body>
+</html>
diff --git a/testing/web-platform/tests/fetch/api/policies/referrer-origin-when-cross-origin-service-worker.https.html b/testing/web-platform/tests/fetch/api/policies/referrer-origin-when-cross-origin-service-worker.https.html
new file mode 100644
index 000000000000..d87192e22711
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/policies/referrer-origin-when-cross-origin-service-worker.https.html
@@ -0,0 +1,17 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title>Fetch in service worker: referrer with origin-when-cross-origin policy</title>
+    <meta name="help" href="https://fetch.spec.whatwg.org/#main-fetch">
+    <meta name="help" href="https://fetch.spec.whatwg.org/#http-network-or-cache-fetch">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+    <script src="/service-workers/service-worker/resources/test-helpers.sub.js"></script>
+  </head>
+  <body>
+    <script>
+      service_worker_test("referrer-origin-when-cross-origin.js?pipe=sub");
+    </script>
+  </body>
+</html>
diff --git a/testing/web-platform/tests/fetch/api/policies/referrer-origin-when-cross-origin.js b/testing/web-platform/tests/fetch/api/policies/referrer-origin-when-cross-origin.js
index 2baf7d12593f..7cd4113f506f 100644
--- a/testing/web-platform/tests/fetch/api/policies/referrer-origin-when-cross-origin.js
+++ b/testing/web-platform/tests/fetch/api/policies/referrer-origin-when-cross-origin.js
@@ -1,10 +1,14 @@
 if (this.document === undefined) {
   importScripts("/resources/testharness.js");
   importScripts("../resources/utils.js");
+
+  // A nested importScripts() with a referrer-policy should have no effect
+  // on overall worker policy.
+  importScripts("nested-policy.js");
 }
 
-var referrerOrigin = "http://{{host}}:{{ports[http][0]}}/";
-var fetchedUrl = "http://{{host}}:{{ports[http][1]}}" + dirname(location.pathname) + RESOURCES_DIR + "inspect-headers.py?cors&headers=referer";
+var referrerOrigin = location.origin + '/';
+var fetchedUrl = "https://{{domains[www]}}:{{ports[https][0]}}" + dirname(location.pathname) + RESOURCES_DIR + "inspect-headers.py?cors&headers=referer";
 
 promise_test(function(test) {
   return fetch(fetchedUrl).then(function(resp) {
diff --git a/testing/web-platform/tests/fetch/api/policies/referrer-origin.html b/testing/web-platform/tests/fetch/api/policies/referrer-origin.html
index 92baed79be76..b164afe01de9 100644
--- a/testing/web-platform/tests/fetch/api/policies/referrer-origin.html
+++ b/testing/web-platform/tests/fetch/api/policies/referrer-origin.html
@@ -13,4 +13,4 @@
     <script src="../resources/utils.js"></script>
     <script src="referrer-origin.js?pipe=sub"></script>
   </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/testing/web-platform/tests/fetch/api/policies/referrer-origin.js b/testing/web-platform/tests/fetch/api/policies/referrer-origin.js
index de187657486d..11541e94da59 100644
--- a/testing/web-platform/tests/fetch/api/policies/referrer-origin.js
+++ b/testing/web-platform/tests/fetch/api/policies/referrer-origin.js
@@ -1,9 +1,13 @@
 if (this.document === undefined) {
   importScripts("/resources/testharness.js");
   importScripts("../resources/utils.js");
+
+  // A nested importScripts() with a referrer-policy should have no effect
+  // on overall worker policy.
+  importScripts("nested-policy.js");
 }
 
-var referrerOrigin = "http://{{host}}:{{ports[http][0]}}/";
+var referrerOrigin = self.location.origin + '/';
 var fetchedUrl = RESOURCES_DIR + "inspect-headers.py?headers=referer";
 
 promise_test(function(test) {
@@ -15,7 +19,7 @@ promise_test(function(test) {
 }, "Request's referrer is origin");
 
 promise_test(function(test) {
-  var referrerUrl = "http://{{domains[www]}}:{{ports[http][0]}}/";
+  var referrerUrl = "https://{{domains[www]}}:{{ports[https][0]}}/";
   return fetch(fetchedUrl, { "referrer": referrerUrl }).then(function(resp) {
     assert_equals(resp.status, 200, "HTTP status is 200");
     assert_equals(resp.type , "basic", "Response's type is basic");
diff --git a/testing/web-platform/tests/fetch/api/policies/referrer-unsafe-url-service-worker.https.html b/testing/web-platform/tests/fetch/api/policies/referrer-unsafe-url-service-worker.https.html
new file mode 100644
index 000000000000..39a65b0e333a
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/policies/referrer-unsafe-url-service-worker.https.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title>Fetch in worker: referrer with unsafe-url policy</title>
+    <meta name="help" href="https://fetch.spec.whatwg.org/#main-fetch">
+    <meta name="help" href="https://fetch.spec.whatwg.org/#http-network-or-cache-fetch">
+    <meta name="author" title="Canon Research France" href="https://www.crf.canon.fr">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+    <script src="/service-workers/service-worker/resources/test-helpers.sub.js"></script>
+  </head>
+  <body>
+    <script>
+      service_worker_test("referrer-unsafe-url.js?pipe=sub");
+    </script>
+  </body>
+</html>
diff --git a/testing/web-platform/tests/fetch/api/policies/referrer-unsafe-url.js b/testing/web-platform/tests/fetch/api/policies/referrer-unsafe-url.js
index b593fad5aa2b..4d61172613ee 100644
--- a/testing/web-platform/tests/fetch/api/policies/referrer-unsafe-url.js
+++ b/testing/web-platform/tests/fetch/api/policies/referrer-unsafe-url.js
@@ -1,6 +1,10 @@
 if (this.document === undefined) {
   importScripts("/resources/testharness.js");
   importScripts("../resources/utils.js");
+
+  // A nested importScripts() with a referrer-policy should have no effect
+  // on overall worker policy.
+  importScripts("nested-policy.js");
 }
 
 var referrerUrl = location.href;
diff --git a/toolkit/components/telemetry/Histograms.json b/toolkit/components/telemetry/Histograms.json
index af2a54499a40..fcc5bfd88fe2 100644
--- a/toolkit/components/telemetry/Histograms.json
+++ b/toolkit/components/telemetry/Histograms.json
@@ -1990,6 +1990,7 @@
     "expires_in_version": "never",
     "kind": "enumerated",
     "n_values": 672,
+    "releaseChannelCollection": "opt-out",      
     "description": "SSL handshake result, 0=success, 1-255=NSS error offset, 256-511=SEC error offset + 256, 512-639=NSPR error offset + 512, 640-670=PKIX error, 671=unknown err"
   },
   "SSL_TIME_UNTIL_READY": {
diff --git a/toolkit/components/telemetry/TelemetryHistogram.cpp b/toolkit/components/telemetry/TelemetryHistogram.cpp
index 9a5366b5f509..89e1da08b3d3 100644
--- a/toolkit/components/telemetry/TelemetryHistogram.cpp
+++ b/toolkit/components/telemetry/TelemetryHistogram.cpp
@@ -1316,9 +1316,6 @@ internal_RemoteAccumulate(mozilla::Telemetry::HistogramID aId,
   KeyedHistogram* keyed
      = internal_GetKeyedHistogramById(nsDependentCString(th.id()));
   MOZ_ASSERT(keyed);
-  // Assert on empty keys as well, we should be filtering them out in
-  // the outer API.
-  MOZ_ASSERT(!aKey.IsEmpty());
   if (!keyed->IsRecordingEnabled()) {
     return false;
   }
@@ -1746,12 +1743,6 @@ internal_JSKeyedHistogram_Add(JSContext *cx, unsigned argc, JS::Value *vp)
     return true;
   }
 
-  if (key.IsEmpty()) {
-    LogToBrowserConsole(nsIScriptError::errorFlag,
-      NS_LITERAL_STRING("Empty histogram keys are not allowed."));
-    return true;
-  }
-
   const uint32_t type = keyed->GetHistogramType();
 
   // If we don't have an argument for the count histogram, assume an increment of 1.
@@ -2145,12 +2136,6 @@ TelemetryHistogram::Accumulate(mozilla::Telemetry::HistogramID aID,
     return;
   }
 
-  if (aKey.IsEmpty()) {
-    LogToBrowserConsole(nsIScriptError::errorFlag,
-      NS_LITERAL_STRING("Empty histogram keys are not allowed."));
-    return;
-  }
-
   StaticMutexAutoLock locker(gTelemetryHistogramMutex);
   internal_Accumulate(aID, aKey, aSample);
 }
@@ -2174,12 +2159,6 @@ void
 TelemetryHistogram::Accumulate(const char* name,
                                const nsCString& key, uint32_t sample)
 {
-  if (key.IsEmpty()) {
-    LogToBrowserConsole(nsIScriptError::errorFlag,
-      NS_LITERAL_STRING("Empty histogram keys are not allowed."));
-    return;
-  }
-
   StaticMutexAutoLock locker(gTelemetryHistogramMutex);
   if (!internal_CanRecordBase()) {
     return;
diff --git a/toolkit/components/telemetry/WebrtcTelemetry.cpp b/toolkit/components/telemetry/WebrtcTelemetry.cpp
index a437bff22f31..8c03f3a99fb0 100644
--- a/toolkit/components/telemetry/WebrtcTelemetry.cpp
+++ b/toolkit/components/telemetry/WebrtcTelemetry.cpp
@@ -12,8 +12,6 @@
 #include "nsPrintfCString.h"
 #include "nsTHashtable.h"
 
-using mozilla::Telemetry::Common::AutoHashtable;
-
 void
 WebrtcTelemetry::RecordIceCandidateMask(const uint32_t iceCandidateBitmask,
                                         const bool success)
diff --git a/toolkit/components/telemetry/docs/collection/histograms.rst b/toolkit/components/telemetry/docs/collection/histograms.rst
index 6a4d4eafa575..7a943a572da7 100644
--- a/toolkit/components/telemetry/docs/collection/histograms.rst
+++ b/toolkit/components/telemetry/docs/collection/histograms.rst
@@ -89,11 +89,7 @@ Keyed Histograms
 ----------------
 
 Keyed histograms are collections of one of the histogram types above, indexed by a string key. This is for example useful when you want to break down certain counts by a name, like how often searches happen with which search engine.
-
-Note that:
-
-- keys can't be empty strings;
-- when you need to record for a small set of known keys, using separate plain histograms is more efficient.
+Note that when you need to record for a small set of known keys, using separate plain histograms is more efficient.
 
 .. warning::
 
@@ -207,11 +203,7 @@ A Telemetry probe is the code that measures and stores values in a histogram. Pr
   let keyed = Services.telemetry.getKeyedHistogramById("TAG_SEEN_COUNTS");
   keyed.add("blink");
 
-Note that:
-
-- ``nsITelemetry.getHistogramById()`` will throw an ``NS_ERROR_ILLEGAL_VALUE`` JavaScript exception if it is called with an invalid histogram ID;
-- the ``add()`` function will not throw on failure, but log an error to the browser console;
-- for keyed histograms, calling ``add()`` with an empty key will be ignored and log an error.
+Note that ``nsITelemetry.getHistogramById()`` will throw an ``NS_ERROR_ILLEGAL_VALUE`` JavaScript exception if it is called with an invalid histogram ID. The ``add()`` function will not throw if it fails, instead it prints an error in the browser console.
 
 For histograms measuring time, `TelemetryStopwatch <https://mxr.mozilla.org/mozilla-central/source/toolkit/components/telemetry/TelemetryStopwatch.jsm>`_ can be used to avoid working with Dates manually:
 
diff --git a/toolkit/components/telemetry/tests/unit/test_TelemetryHistograms.js b/toolkit/components/telemetry/tests/unit/test_TelemetryHistograms.js
index 55b9355f22a1..16650773126b 100644
--- a/toolkit/components/telemetry/tests/unit/test_TelemetryHistograms.js
+++ b/toolkit/components/telemetry/tests/unit/test_TelemetryHistograms.js
@@ -487,15 +487,6 @@ add_task(function* test_keyed_histogram() {
     threw = true;
   }
   Assert.ok(threw, "getKeyedHistogramById should have thrown");
-
-  // Check that empty keys are not allowed.
-  const KEYED_ID = "TELEMETRY_TEST_KEYED_COUNT";
-  let h = Telemetry.getKeyedHistogramById(KEYED_ID);
-
-  // Try to add to an empty key and make sure nothing happens.
-  h.add("");
-  Assert.ok(!("" in h.snapshot()),
-            "Keyed histogram should not allow empty keys.");
 });
 
 add_task(function* test_keyed_boolean_histogram() {
diff --git a/toolkit/content/aboutSupport.js b/toolkit/content/aboutSupport.js
index 6fc6ad28cca1..b8f4f0c059c9 100644
--- a/toolkit/content/aboutSupport.js
+++ b/toolkit/content/aboutSupport.js
@@ -376,14 +376,16 @@ var snapshotFormatters = {
            apzInfo.length
            ? apzInfo.join("; ")
            : localizedMsg(["apzNone"]));
+    addRowFromKey("features", "webgl1WSIInfo");
     addRowFromKey("features", "webgl1Renderer");
     addRowFromKey("features", "webgl1Version");
+    addRowFromKey("features", "webgl1DriverExtensions");
     addRowFromKey("features", "webgl1Extensions");
-    addRowFromKey("features", "webgl1WSIInfo");
+    addRowFromKey("features", "webgl2WSIInfo");
     addRowFromKey("features", "webgl2Renderer");
     addRowFromKey("features", "webgl2Version");
+    addRowFromKey("features", "webgl2DriverExtensions");
     addRowFromKey("features", "webgl2Extensions");
-    addRowFromKey("features", "webgl2WSIInfo");
     addRowFromKey("features", "supportsHardwareH264", "hardwareH264");
     addRowFromKey("features", "currentAudioBackend", "audioBackend");
     addRowFromKey("features", "direct2DEnabled", "#Direct2D");
diff --git a/toolkit/library/gtest/rust/Cargo.toml b/toolkit/library/gtest/rust/Cargo.toml
index 21627fc580aa..8d6e6b6ae6df 100644
--- a/toolkit/library/gtest/rust/Cargo.toml
+++ b/toolkit/library/gtest/rust/Cargo.toml
@@ -39,11 +39,6 @@ panic = "abort"
 opt-level = 2
 debug = true
 rpath = false
-# This would normally be 'true' for release configurations, but using LTO on
-# rul-gtest causes link failures due to symbols also being found in libxul's
-# librul.a.  But LTO'ing things here is not crucial and not LTO'ing things
-# enables us to link libxul-gtest, so we leave it turned off.
-lto = false
+lto = true
 debug-assertions = false
-codegen-units = 1
 panic = "abort"
diff --git a/toolkit/library/gtest/rust/moz.build b/toolkit/library/gtest/rust/moz.build
index 6fe3f8931bc2..26ba750e09f3 100644
--- a/toolkit/library/gtest/rust/moz.build
+++ b/toolkit/library/gtest/rust/moz.build
@@ -14,4 +14,4 @@ if CONFIG['MOZ_STYLO']:
 if CONFIG['MOZ_ENABLE_WEBRENDER']:
     features += ['quantum_render']
 
-RustLibrary('gkrust-gtest', features)
+RustLibrary('gkrust-gtest', features, '../..')
diff --git a/toolkit/library/rust/moz.build b/toolkit/library/rust/moz.build
index a5cec1fbbf19..069a8d4ecde7 100644
--- a/toolkit/library/rust/moz.build
+++ b/toolkit/library/rust/moz.build
@@ -14,4 +14,4 @@ if CONFIG['MOZ_STYLO']:
 if CONFIG['MOZ_ENABLE_WEBRENDER']:
     features += ['quantum_render']
 
-RustLibrary('gkrust', features)
+RustLibrary('gkrust', features, '..')
diff --git a/toolkit/locales/en-US/chrome/global/aboutSupport.properties b/toolkit/locales/en-US/chrome/global/aboutSupport.properties
index 09298359a1a5..d19dcd03cdae 100644
--- a/toolkit/locales/en-US/chrome/global/aboutSupport.properties
+++ b/toolkit/locales/en-US/chrome/global/aboutSupport.properties
@@ -71,14 +71,16 @@ gpuRAM = RAM
 gpuDriverVersion = Driver Version
 gpuDriverDate = Driver Date
 gpuActive = Active
-webgl1Renderer = WebGL 1 Renderer
-webgl1Version = WebGL 1 GL Version
-webgl1Extensions = WebGL 1 GL Extensions
-webgl1WSIInfo = WebGL 1 WSI Info
-webgl2Renderer = WebGL 2 Renderer
-webgl2Version = WebGL 2 GL Version
-webgl2Extensions = WebGL 2 GL Extensions
-webgl2WSIInfo = WebGL 2 WSI Info
+webgl1WSIInfo = WebGL 1 Driver WSI Info
+webgl1Renderer = WebGL 1 Driver Renderer
+webgl1Version = WebGL 1 Driver Version
+webgl1DriverExtensions = WebGL 1 Driver Extensions
+webgl1Extensions = WebGL 1 Extensions
+webgl2WSIInfo = WebGL 2 Driver WSI Info
+webgl2Renderer = WebGL 2 Driver Renderer
+webgl2Version = WebGL 2 Driver Version
+webgl2DriverExtensions = WebGL 2 Driver Extensions
+webgl2Extensions = WebGL 2 Extensions
 GPU1 = GPU #1
 GPU2 = GPU #2
 blocklistedBug = Blocklisted due to known issues
diff --git a/toolkit/modules/Troubleshoot.jsm b/toolkit/modules/Troubleshoot.jsm
index dbb114cb45b7..09991395f224 100644
--- a/toolkit/modules/Troubleshoot.jsm
+++ b/toolkit/modules/Troubleshoot.jsm
@@ -422,6 +422,7 @@ var dataProviders = {
     function GetWebGLInfo(data, keyPrefix, contextType) {
         data[keyPrefix + "Renderer"] = "-";
         data[keyPrefix + "Version"] = "-";
+        data[keyPrefix + "DriverExtensions"] = "-";
         data[keyPrefix + "Extensions"] = "-";
         data[keyPrefix + "WSIInfo"] = "-";
 
@@ -458,6 +459,10 @@ var dataProviders = {
 
         // //
 
+        data[keyPrefix + "Extensions"] = gl.getSupportedExtensions().join(" ");
+
+        // //
+
         let ext = gl.getExtension("MOZ_debug_get");
         // This extension is unconditionally available to chrome. No need to check.
         let vendor = ext.getParameter(gl.VENDOR);
@@ -465,7 +470,7 @@ var dataProviders = {
 
         data[keyPrefix + "Renderer"] = vendor + " -- " + renderer;
         data[keyPrefix + "Version"] = ext.getParameter(gl.VERSION);
-        data[keyPrefix + "Extensions"] = ext.getParameter(ext.EXTENSIONS);
+        data[keyPrefix + "DriverExtensions"] = ext.getParameter(ext.EXTENSIONS);
         data[keyPrefix + "WSIInfo"] = ext.getParameter(ext.WSI_INFO);
 
         // //
diff --git a/toolkit/modules/tests/browser/browser_Troubleshoot.js b/toolkit/modules/tests/browser/browser_Troubleshoot.js
index d3c7711196ba..b1a9d71f90b2 100644
--- a/toolkit/modules/tests/browser/browser_Troubleshoot.js
+++ b/toolkit/modules/tests/browser/browser_Troubleshoot.js
@@ -300,6 +300,9 @@ const SNAPSHOT_SCHEMA = {
         webgl1Version: {
           type: "string",
         },
+        webgl1DriverExtensions: {
+          type: "string",
+        },
         webgl1Extensions: {
           type: "string",
         },
@@ -312,6 +315,9 @@ const SNAPSHOT_SCHEMA = {
         webgl2Version: {
           type: "string",
         },
+        webgl2DriverExtensions: {
+          type: "string",
+        },
         webgl2Extensions: {
           type: "string",
         },
diff --git a/toolkit/themes/linux/global/button.css b/toolkit/themes/linux/global/button.css
index cdcc66c53945..6ed09c94ca0b 100644
--- a/toolkit/themes/linux/global/button.css
+++ b/toolkit/themes/linux/global/button.css
@@ -20,7 +20,6 @@ button {
 
 .button-box {
   -moz-appearance: button-focus;
-  border: 1px solid transparent;
   padding-top: 1px;
   padding-bottom: 2px;
   padding-inline-start: 3px;
@@ -36,12 +35,6 @@ button {
   text-align: center;
 }
 
-/* .......... focused state .......... */
-
-button:focus > .button-box {
-  border: 1px dotted ThreeDDarkShadow;
-}
-
 /* .......... hover state .......... */
 
 button:hover {
diff --git a/tools/profiler/core/ProfileBuffer.cpp b/tools/profiler/core/ProfileBuffer.cpp
index 864f212b3bf4..3ae360420c1a 100644
--- a/tools/profiler/core/ProfileBuffer.cpp
+++ b/tools/profiler/core/ProfileBuffer.cpp
@@ -6,7 +6,7 @@
 #include "ProfileBuffer.h"
 
 ProfileBuffer::ProfileBuffer(int aEntrySize)
-  : mEntries(mozilla::MakeUnique<ProfileEntry[]>(aEntrySize))
+  : mEntries(mozilla::MakeUnique<ProfileBufferEntry[]>(aEntrySize))
   , mWritePos(0)
   , mReadPos(0)
   , mEntrySize(aEntrySize)
@@ -22,7 +22,7 @@ ProfileBuffer::~ProfileBuffer()
 }
 
 // Called from signal, call only reentrant functions
-void ProfileBuffer::addTag(const ProfileEntry& aTag)
+void ProfileBuffer::addTag(const ProfileBufferEntry& aTag)
 {
   mEntries[mWritePos++] = aTag;
   if (mWritePos == mEntrySize) {
@@ -34,7 +34,7 @@ void ProfileBuffer::addTag(const ProfileEntry& aTag)
   }
   if (mWritePos == mReadPos) {
     // Keep one slot open.
-    mEntries[mReadPos] = ProfileEntry();
+    mEntries[mReadPos] = ProfileBufferEntry();
     mReadPos = (mReadPos + 1) % mEntrySize;
   }
 }
@@ -85,7 +85,7 @@ char* ProfileBuffer::processDynamicTag(int readPos,
   bool seenNullByte = false;
   while (readAheadPos != mWritePos && !seenNullByte) {
     (*tagsConsumed)++;
-    ProfileEntry readAheadEntry = mEntries[readAheadPos];
+    ProfileBufferEntry readAheadEntry = mEntries[readAheadPos];
     for (size_t pos = 0; pos < sizeof(void*); pos++) {
       tagBuff[tagBuffPos] = readAheadEntry.mTagChars[pos];
       if (tagBuff[tagBuffPos] == '\0' || tagBuffPos == DYNAMIC_MAX_STRING-2) {
diff --git a/tools/profiler/core/ProfileBuffer.h b/tools/profiler/core/ProfileBuffer.h
index 427afcd379f1..93d549d83b4e 100644
--- a/tools/profiler/core/ProfileBuffer.h
+++ b/tools/profiler/core/ProfileBuffer.h
@@ -6,7 +6,7 @@
 #ifndef MOZ_PROFILE_BUFFER_H
 #define MOZ_PROFILE_BUFFER_H
 
-#include "ProfileEntry.h"
+#include "ProfileBufferEntry.h"
 #include "platform.h"
 #include "ProfileJSONWriter.h"
 #include "mozilla/RefPtr.h"
@@ -21,7 +21,7 @@ public:
 
   virtual ~ProfileBuffer();
 
-  void addTag(const ProfileEntry& aTag);
+  void addTag(const ProfileBufferEntry& aTag);
   void StreamSamplesToJSON(SpliceableJSONWriter& aWriter, int aThreadId, double aSinceTime,
                            JSContext* cx, UniqueStacks& aUniqueStacks);
   void StreamMarkersToJSON(SpliceableJSONWriter& aWriter, int aThreadId, double aSinceTime,
@@ -42,7 +42,7 @@ protected:
 
 public:
   // Circular buffer 'Keep One Slot Open' implementation for simplicity
-  mozilla::UniquePtr<ProfileEntry[]> mEntries;
+  mozilla::UniquePtr<ProfileBufferEntry[]> mEntries;
 
   // Points to the next entry we will write to, which is also the one at which
   // we need to stop reading.
diff --git a/tools/profiler/core/ProfileEntry.cpp b/tools/profiler/core/ProfileBufferEntry.cpp
similarity index 93%
rename from tools/profiler/core/ProfileEntry.cpp
rename to tools/profiler/core/ProfileBufferEntry.cpp
index 8a3cc88edf16..9a5acdb95488 100644
--- a/tools/profiler/core/ProfileEntry.cpp
+++ b/tools/profiler/core/ProfileBufferEntry.cpp
@@ -16,7 +16,7 @@
 #include "js/TrackedOptimizationInfo.h"
 
 // Self
-#include "ProfileEntry.h"
+#include "ProfileBufferEntry.h"
 
 using mozilla::JSONWriter;
 using mozilla::MakeUnique;
@@ -27,55 +27,55 @@ using mozilla::TimeStamp;
 using mozilla::UniquePtr;
 
 ////////////////////////////////////////////////////////////////////////
-// BEGIN ProfileEntry
+// BEGIN ProfileBufferEntry
 
-ProfileEntry::ProfileEntry()
+ProfileBufferEntry::ProfileBufferEntry()
   : mTagData(nullptr)
   , mKind(Kind::INVALID)
 { }
 
 // aTagData must not need release (i.e. be a string from the text segment)
-ProfileEntry::ProfileEntry(Kind aKind, const char *aTagData)
+ProfileBufferEntry::ProfileBufferEntry(Kind aKind, const char *aTagData)
   : mTagData(aTagData)
   , mKind(aKind)
 { }
 
-ProfileEntry::ProfileEntry(Kind aKind, ProfilerMarker *aTagMarker)
+ProfileBufferEntry::ProfileBufferEntry(Kind aKind, ProfilerMarker *aTagMarker)
   : mTagMarker(aTagMarker)
   , mKind(aKind)
 { }
 
-ProfileEntry::ProfileEntry(Kind aKind, void *aTagPtr)
+ProfileBufferEntry::ProfileBufferEntry(Kind aKind, void *aTagPtr)
   : mTagPtr(aTagPtr)
   , mKind(aKind)
 { }
 
-ProfileEntry::ProfileEntry(Kind aKind, double aTagDouble)
+ProfileBufferEntry::ProfileBufferEntry(Kind aKind, double aTagDouble)
   : mTagDouble(aTagDouble)
   , mKind(aKind)
 { }
 
-ProfileEntry::ProfileEntry(Kind aKind, uintptr_t aTagOffset)
+ProfileBufferEntry::ProfileBufferEntry(Kind aKind, uintptr_t aTagOffset)
   : mTagOffset(aTagOffset)
   , mKind(aKind)
 { }
 
-ProfileEntry::ProfileEntry(Kind aKind, Address aTagAddress)
+ProfileBufferEntry::ProfileBufferEntry(Kind aKind, Address aTagAddress)
   : mTagAddress(aTagAddress)
   , mKind(aKind)
 { }
 
-ProfileEntry::ProfileEntry(Kind aKind, int aTagInt)
+ProfileBufferEntry::ProfileBufferEntry(Kind aKind, int aTagInt)
   : mTagInt(aTagInt)
   , mKind(aKind)
 { }
 
-ProfileEntry::ProfileEntry(Kind aKind, char aTagChar)
+ProfileBufferEntry::ProfileBufferEntry(Kind aKind, char aTagChar)
   : mTagChar(aTagChar)
   , mKind(aKind)
 { }
 
-// END ProfileEntry
+// END ProfileBufferEntry
 ////////////////////////////////////////////////////////////////////////
 
 class JSONSchemaWriter
@@ -153,8 +153,8 @@ public:
   }
 };
 
-// As mentioned in ProfileEntry.h, the JSON format contains many arrays whose
-// elements are laid out according to various schemas to help
+// As mentioned in ProfileBufferEntry.h, the JSON format contains many
+// arrays whose elements are laid out according to various schemas to help
 // de-duplication. This RAII class helps write these arrays by keeping track of
 // the last non-null element written and adding the appropriate number of null
 // elements when writing new non-null elements. It also automatically opens and
@@ -589,13 +589,13 @@ void ProfileBuffer::StreamSamplesToJSON(SpliceableJSONWriter& aWriter, int aThre
   UniquePtr<char[]> tagBuff = MakeUnique<char[]>(DYNAMIC_MAX_STRING);
 
   while (readPos != mWritePos) {
-    ProfileEntry entry = mEntries[readPos];
+    ProfileBufferEntry entry = mEntries[readPos];
     if (entry.isThreadId()) {
       currentThreadID = entry.mTagInt;
       currentTime.reset();
       int readAheadPos = (readPos + 1) % mEntrySize;
       if (readAheadPos != mWritePos) {
-        ProfileEntry readAheadEntry = mEntries[readAheadPos];
+        ProfileBufferEntry readAheadEntry = mEntries[readAheadPos];
         if (readAheadEntry.isTime()) {
           currentTime = Some(readAheadEntry.mTagDouble);
         }
@@ -603,27 +603,27 @@ void ProfileBuffer::StreamSamplesToJSON(SpliceableJSONWriter& aWriter, int aThre
     }
     if (currentThreadID == aThreadId && (currentTime.isNothing() || *currentTime >= aSinceTime)) {
       switch (entry.kind()) {
-      case ProfileEntry::Kind::Responsiveness:
+      case ProfileBufferEntry::Kind::Responsiveness:
         if (sample.isSome()) {
           sample->mResponsiveness = Some(entry.mTagDouble);
         }
         break;
-      case ProfileEntry::Kind::ResidentMemory:
+      case ProfileBufferEntry::Kind::ResidentMemory:
         if (sample.isSome()) {
           sample->mRSS = Some(entry.mTagDouble);
         }
         break;
-      case ProfileEntry::Kind::UnsharedMemory:
+      case ProfileBufferEntry::Kind::UnsharedMemory:
         if (sample.isSome()) {
           sample->mUSS = Some(entry.mTagDouble);
          }
         break;
-      case ProfileEntry::Kind::FrameNumber:
+      case ProfileBufferEntry::Kind::FrameNumber:
         if (sample.isSome()) {
           sample->mFrameNumber = Some(entry.mTagInt);
         }
         break;
-      case ProfileEntry::Kind::Sample:
+      case ProfileBufferEntry::Kind::Sample:
         {
           // end the previous sample if there was one
           if (sample.isSome()) {
@@ -642,7 +642,7 @@ void ProfileBuffer::StreamSamplesToJSON(SpliceableJSONWriter& aWriter, int aThre
             aUniqueStacks.BeginStack(UniqueStacks::OnStackFrameKey("(root)"));
 
           int framePos = (readPos + 1) % mEntrySize;
-          ProfileEntry frame = mEntries[framePos];
+          ProfileBufferEntry frame = mEntries[framePos];
           while (framePos != mWritePos && !frame.isSample() && !frame.isThreadId()) {
             int incBy = 1;
             frame = mEntries[framePos];
@@ -725,7 +725,7 @@ void ProfileBuffer::StreamMarkersToJSON(SpliceableJSONWriter& aWriter, int aThre
   int readPos = mReadPos;
   int currentThreadID = -1;
   while (readPos != mWritePos) {
-    ProfileEntry entry = mEntries[readPos];
+    ProfileBufferEntry entry = mEntries[readPos];
     if (entry.isThreadId()) {
       currentThreadID = entry.mTagInt;
     } else if (currentThreadID == aThreadId && entry.isMarker()) {
@@ -745,7 +745,7 @@ int ProfileBuffer::FindLastSampleOfThread(int aThreadId)
   for (int readPos  = (mWritePos + mEntrySize - 1) % mEntrySize;
            readPos !=  (mReadPos + mEntrySize - 1) % mEntrySize;
            readPos  =   (readPos + mEntrySize - 1) % mEntrySize) {
-    ProfileEntry entry = mEntries[readPos];
+    ProfileBufferEntry entry = mEntries[readPos];
     if (entry.isThreadId() && entry.mTagInt == aThreadId) {
       return readPos;
     }
@@ -771,14 +771,15 @@ ProfileBuffer::DuplicateLastSample(int aThreadId, const TimeStamp& aStartTime)
        readPos != mWritePos;
        readPos = (readPos + 1) % mEntrySize) {
     switch (mEntries[readPos].kind()) {
-      case ProfileEntry::Kind::ThreadId:
+      case ProfileBufferEntry::Kind::ThreadId:
         // We're done.
         return;
-      case ProfileEntry::Kind::Time:
+      case ProfileBufferEntry::Kind::Time:
         // Copy with new time
-        addTag(ProfileEntry::Time((TimeStamp::Now() - aStartTime).ToMilliseconds()));
+        addTag(ProfileBufferEntry::Time((TimeStamp::Now() -
+                                         aStartTime).ToMilliseconds()));
         break;
-      case ProfileEntry::Kind::Marker:
+      case ProfileBufferEntry::Kind::Marker:
         // Don't copy markers
         break;
       default:
diff --git a/tools/profiler/core/ProfileEntry.h b/tools/profiler/core/ProfileBufferEntry.h
similarity index 92%
rename from tools/profiler/core/ProfileEntry.h
rename to tools/profiler/core/ProfileBufferEntry.h
index 6cec5b0babe1..25c328d8d6a2 100644
--- a/tools/profiler/core/ProfileEntry.h
+++ b/tools/profiler/core/ProfileBufferEntry.h
@@ -4,8 +4,8 @@
  * 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 MOZ_PROFILE_ENTRY_H
-#define MOZ_PROFILE_ENTRY_H
+#ifndef ProfileBufferEntry_h
+#define ProfileBufferEntry_h
 
 #include <ostream>
 #include "GeckoProfiler.h"
@@ -25,7 +25,7 @@
 #include "mozilla/HashFunctions.h"
 #include "mozilla/UniquePtr.h"
 
-#define PROFILE_ENTRY_KIND_LIST(_) \
+#define PROFILE_BUFFER_ENTRY_KIND_LIST(_) \
     _(Category,        int)               \
     _(CodeLocation,    const char *)      \
     _(EmbeddedString,  void *)            \
@@ -46,34 +46,36 @@
 #pragma pack(push, 1)
 #endif
 
-class ProfileEntry
+class ProfileBufferEntry
 {
 public:
   enum class Kind : uint8_t {
     INVALID = 0,
 #   define DEF_ENUM_(k, t) k,
-    PROFILE_ENTRY_KIND_LIST(DEF_ENUM_)
+    PROFILE_BUFFER_ENTRY_KIND_LIST(DEF_ENUM_)
 #   undef DEF_ENUM_
     LIMIT
   };
 
-  ProfileEntry();
+  ProfileBufferEntry();
 
 private:
   // aTagData must not need release (i.e. be a string from the text segment)
-  ProfileEntry(Kind aKind, const char *aTagData);
-  ProfileEntry(Kind aKind, void *aTagPtr);
-  ProfileEntry(Kind aKind, ProfilerMarker *aTagMarker);
-  ProfileEntry(Kind aKind, double aTagDouble);
-  ProfileEntry(Kind aKind, uintptr_t aTagOffset);
-  ProfileEntry(Kind aKind, Address aTagAddress);
-  ProfileEntry(Kind aKind, int aTagLine);
-  ProfileEntry(Kind aKind, char aTagChar);
+  ProfileBufferEntry(Kind aKind, const char *aTagData);
+  ProfileBufferEntry(Kind aKind, void *aTagPtr);
+  ProfileBufferEntry(Kind aKind, ProfilerMarker *aTagMarker);
+  ProfileBufferEntry(Kind aKind, double aTagDouble);
+  ProfileBufferEntry(Kind aKind, uintptr_t aTagOffset);
+  ProfileBufferEntry(Kind aKind, Address aTagAddress);
+  ProfileBufferEntry(Kind aKind, int aTagLine);
+  ProfileBufferEntry(Kind aKind, char aTagChar);
 
 public:
 # define DEF_MAKE_(k, t) \
-    static ProfileEntry k(t val) { return ProfileEntry(Kind::k, val); }
-  PROFILE_ENTRY_KIND_LIST(DEF_MAKE_)
+    static ProfileBufferEntry k(t val) { \
+      return ProfileBufferEntry(Kind::k, val); \
+    }
+  PROFILE_BUFFER_ENTRY_KIND_LIST(DEF_MAKE_)
 # undef DEF_MAKE_
 
   Kind kind() const { return mKind; }
@@ -81,7 +83,7 @@ public:
 
 # define DEF_METHODS_(k, t) \
     bool is##k() const { return hasKind(Kind::k); }
-  PROFILE_ENTRY_KIND_LIST(DEF_METHODS_)
+  PROFILE_BUFFER_ENTRY_KIND_LIST(DEF_METHODS_)
 # undef DEF_METHODS_
 
   const ProfilerMarker* getMarker() {
@@ -408,4 +410,4 @@ private:
 // }
 //
 
-#endif /* ndef MOZ_PROFILE_ENTRY_H */
+#endif /* ndef ProfileBufferEntry_h */
diff --git a/tools/profiler/core/SyncProfile.cpp b/tools/profiler/core/SyncProfile.cpp
index c164f0e51798..4b092bd5b138 100644
--- a/tools/profiler/core/SyncProfile.cpp
+++ b/tools/profiler/core/SyncProfile.cpp
@@ -12,7 +12,7 @@ SyncProfile::SyncProfile(int aThreadId, PseudoStack* aStack)
   , mOwnerState(REFERENCED)
 {
   MOZ_COUNT_CTOR(SyncProfile);
-  SetProfile(new ProfileBuffer(GET_BACKTRACE_DEFAULT_ENTRY));
+  SetProfile(new ProfileBuffer(GET_BACKTRACE_DEFAULT_ENTRIES));
 }
 
 SyncProfile::~SyncProfile()
diff --git a/tools/profiler/core/SyncProfile.h b/tools/profiler/core/SyncProfile.h
index af7689002a40..96ebaafcfd62 100644
--- a/tools/profiler/core/SyncProfile.h
+++ b/tools/profiler/core/SyncProfile.h
@@ -7,7 +7,6 @@
 #ifndef __SYNCPROFILE_H
 #define __SYNCPROFILE_H
 
-#include "ProfileEntry.h"
 #include "ThreadInfo.h"
 
 class SyncProfile : public ThreadInfo
diff --git a/tools/profiler/core/ThreadInfo.cpp b/tools/profiler/core/ThreadInfo.cpp
index 808d7834f79b..35f1b7d778f2 100644
--- a/tools/profiler/core/ThreadInfo.cpp
+++ b/tools/profiler/core/ThreadInfo.cpp
@@ -64,7 +64,7 @@ ThreadInfo::CanInvokeJS() const
 }
 
 void
-ThreadInfo::addTag(const ProfileEntry& aTag)
+ThreadInfo::addTag(const ProfileBufferEntry& aTag)
 {
   mBuffer->addTag(aTag);
 }
diff --git a/tools/profiler/core/ThreadInfo.h b/tools/profiler/core/ThreadInfo.h
index addfb6d7b402..8da8e783df10 100644
--- a/tools/profiler/core/ThreadInfo.h
+++ b/tools/profiler/core/ThreadInfo.h
@@ -57,7 +57,7 @@ class ThreadInfo {
 public:
   bool hasProfile() { return !!mBuffer; }
 
-  void addTag(const ProfileEntry& aTag);
+  void addTag(const ProfileBufferEntry& aTag);
 
   // Track a marker which has been inserted into the thread profile.
   // This marker can safely be deleted once the generation has
diff --git a/tools/profiler/core/platform-linux-android.cpp b/tools/profiler/core/platform-linux-android.cpp
index 7713b837ba73..bdb481dbe407 100644
--- a/tools/profiler/core/platform-linux-android.cpp
+++ b/tools/profiler/core/platform-linux-android.cpp
@@ -63,7 +63,6 @@
 #include "prenv.h"
 #include "mozilla/LinuxSignal.h"
 #include "mozilla/DebugOnly.h"
-#include "ProfileEntry.h"
 
 // Memory profile
 #include "nsMemoryReporterManager.h"
@@ -458,10 +457,12 @@ static uint32_t readCSVArray(char* csvList, const char** buffer) {
   return count;
 }
 
-// Currently support only the env variables
-// reported in read_profiler_env
-static void ReadProfilerVars(const char* fileName, const char** features,
-                            uint32_t* featureCount, const char** threadNames, uint32_t* threadCount) {
+// Support some of the env variables reported in ReadProfilerEnvVars, plus some
+// extra stuff.
+static void
+ReadProfilerVars(const char* fileName,
+                 const char** features, uint32_t* featureCount,
+                 const char** threadNames, uint32_t* threadCount) {
   FILE* file = fopen(fileName, "r");
   const int bufferSize = 1024;
   char line[bufferSize];
@@ -474,11 +475,11 @@ static void ReadProfilerVars(const char* fileName, const char** features,
       feature = strtok_r(line, "=", &savePtr);
       value = strtok_r(NULL, "", &savePtr);
 
-      if (strncmp(feature, PROFILER_INTERVAL, bufferSize) == 0) {
+      if (strncmp(feature, "MOZ_PROFILER_INTERVAL", bufferSize) == 0) {
         set_profiler_interval(value);
-      } else if (strncmp(feature, PROFILER_ENTRIES, bufferSize) == 0) {
+      } else if (strncmp(feature, "MOZ_PROFILER_ENTRIES", bufferSize) == 0) {
         set_profiler_entries(value);
-      } else if (strncmp(feature, PROFILER_FEATURES, bufferSize) == 0) {
+      } else if (strncmp(feature, "MOZ_PROFILER_FEATURES", bufferSize) == 0) {
         *featureCount = readCSVArray(value, features);
       } else if (strncmp(feature, "threads", bufferSize) == 0) {
         *threadCount = readCSVArray(value, threadNames);
@@ -505,9 +506,8 @@ static void DoStartTask() {
   MOZ_ASSERT(featureCount < 10);
   MOZ_ASSERT(threadCount < 10);
 
-  profiler_start(PROFILE_DEFAULT_ENTRY, 1,
-      features, featureCount,
-      threadNames, threadCount);
+  profiler_start(PROFILE_DEFAULT_ENTRIES, /* interval */ 1,
+                 features, featureCount, threadNames, threadCount);
 
   freeArray(threadNames, threadCount);
   freeArray(features, featureCount);
diff --git a/tools/profiler/core/platform-win32.cpp b/tools/profiler/core/platform-win32.cpp
index e66438025a37..26ed3bc50df6 100644
--- a/tools/profiler/core/platform-win32.cpp
+++ b/tools/profiler/core/platform-win32.cpp
@@ -31,7 +31,6 @@
 #include <windows.h>
 #include <mmsystem.h>
 #include <process.h>
-#include "ProfileEntry.h"
 
 // Memory profile
 #include "nsMemoryReporterManager.h"
diff --git a/tools/profiler/core/platform.cpp b/tools/profiler/core/platform.cpp
index b268e9237121..89c63bdf634d 100644
--- a/tools/profiler/core/platform.cpp
+++ b/tools/profiler/core/platform.cpp
@@ -119,8 +119,8 @@ static mozilla::StaticMutex gThreadNameFiltersMutex;
 // All accesses to gFeatures are on the main thread, so no locking is needed.
 static Vector<std::string> gFeatures;
 
-// All accesses to gEntrySize are on the main thread, so no locking is needed.
-static int gEntrySize = 0;
+// All accesses to gEntries are on the main thread, so no locking is needed.
+static int gEntries = 0;
 
 // All accesses to gInterval are on the main thread, so no locking is needed.
 static double gInterval = 0;
@@ -173,8 +173,8 @@ static Atomic<bool> gUseStackWalk(false);
  * to know are associated with different events */
 
 // Values harvested from env vars, that control the profiler.
-static int gUnwindInterval;   /* in milliseconds */
-static int gProfileEntries;   /* how many entries do we store? */
+static int gEnvVarEntries;    /* how many entries do we store? */
+static int gEnvVarInterval;   /* in milliseconds */
 
 static mozilla::StaticAutoPtr<mozilla::ProfilerIOInterposeObserver>
                                                             gInterposeObserver;
@@ -232,7 +232,7 @@ public:
 static void
 AddDynamicCodeLocationTag(ThreadInfo& aInfo, const char* aStr)
 {
-  aInfo.addTag(ProfileEntry::CodeLocation(""));
+  aInfo.addTag(ProfileBufferEntry::CodeLocation(""));
 
   size_t strLen = strlen(aStr) + 1;   // +1 for the null terminator
   for (size_t j = 0; j < strLen; ) {
@@ -246,17 +246,17 @@ AddDynamicCodeLocationTag(ThreadInfo& aInfo, const char* aStr)
     j += sizeof(void*) / sizeof(char);
 
     // Cast to *((void**) to pass the text data to a void*.
-    aInfo.addTag(ProfileEntry::EmbeddedString(*((void**)(&text[0]))));
+    aInfo.addTag(ProfileBufferEntry::EmbeddedString(*((void**)(&text[0]))));
   }
 }
 
 static void
-AddPseudoEntry(volatile StackEntry& entry, ThreadInfo& aInfo,
+AddPseudoEntry(volatile js::ProfileEntry& entry, ThreadInfo& aInfo,
                PseudoStack* stack, void* lastpc)
 {
   // Pseudo-frames with the BEGIN_PSEUDO_JS flag are just annotations and
   // should not be recorded in the profile.
-  if (entry.hasFlag(StackEntry::BEGIN_PSEUDO_JS)) {
+  if (entry.hasFlag(js::ProfileEntry::BEGIN_PSEUDO_JS)) {
     return;
   }
 
@@ -293,7 +293,7 @@ AddPseudoEntry(volatile StackEntry& entry, ThreadInfo& aInfo,
       lineno = entry.line();
     }
   } else {
-    aInfo.addTag(ProfileEntry::CodeLocation(sampleLabel));
+    aInfo.addTag(ProfileBufferEntry::CodeLocation(sampleLabel));
 
     // XXX: Bug 1010578. Don't assume a CPP entry and try to get the line for
     // js entries as well.
@@ -303,15 +303,15 @@ AddPseudoEntry(volatile StackEntry& entry, ThreadInfo& aInfo,
   }
 
   if (lineno != -1) {
-    aInfo.addTag(ProfileEntry::LineNumber(lineno));
+    aInfo.addTag(ProfileBufferEntry::LineNumber(lineno));
   }
 
   uint32_t category = entry.category();
-  MOZ_ASSERT(!(category & StackEntry::IS_CPP_ENTRY));
-  MOZ_ASSERT(!(category & StackEntry::FRAME_LABEL_COPY));
+  MOZ_ASSERT(!(category & js::ProfileEntry::IS_CPP_ENTRY));
+  MOZ_ASSERT(!(category & js::ProfileEntry::FRAME_LABEL_COPY));
 
   if (category) {
-    aInfo.addTag(ProfileEntry::Category((int)category));
+    aInfo.addTag(ProfileBufferEntry::Category((int)category));
   }
 }
 
@@ -345,7 +345,7 @@ MergeStacksIntoProfile(ThreadInfo& aInfo, TickSample* aSample,
                        NativeStack& aNativeStack)
 {
   PseudoStack* pseudoStack = aInfo.Stack();
-  volatile StackEntry* pseudoFrames = pseudoStack->mStack;
+  volatile js::ProfileEntry* pseudoFrames = pseudoStack->mStack;
   uint32_t pseudoCount = pseudoStack->stackSize();
 
   // Make a copy of the JS stack into a JSFrame array. This is necessary since,
@@ -399,7 +399,7 @@ MergeStacksIntoProfile(ThreadInfo& aInfo, TickSample* aSample,
   }
 
   // Start the sample with a root entry.
-  aInfo.addTag(ProfileEntry::Sample("(root)"));
+  aInfo.addTag(ProfileBufferEntry::Sample("(root)"));
 
   // While the pseudo-stack array is ordered oldest-to-youngest, the JS and
   // native arrays are ordered youngest-to-oldest. We must add frames to aInfo
@@ -420,7 +420,7 @@ MergeStacksIntoProfile(ThreadInfo& aInfo, TickSample* aSample,
     uint8_t* nativeStackAddr = nullptr;
 
     if (pseudoIndex != pseudoCount) {
-      volatile StackEntry& pseudoFrame = pseudoFrames[pseudoIndex];
+      volatile js::ProfileEntry& pseudoFrame = pseudoFrames[pseudoIndex];
 
       if (pseudoFrame.isCpp()) {
         lastPseudoCppStackAddr = (uint8_t*) pseudoFrame.stackAddress();
@@ -471,7 +471,7 @@ MergeStacksIntoProfile(ThreadInfo& aInfo, TickSample* aSample,
     // Check to see if pseudoStack frame is top-most.
     if (pseudoStackAddr > jsStackAddr && pseudoStackAddr > nativeStackAddr) {
       MOZ_ASSERT(pseudoIndex < pseudoCount);
-      volatile StackEntry& pseudoFrame = pseudoFrames[pseudoIndex];
+      volatile js::ProfileEntry& pseudoFrame = pseudoFrames[pseudoIndex];
       AddPseudoEntry(pseudoFrame, aInfo, pseudoStack, nullptr);
       pseudoIndex++;
       continue;
@@ -502,7 +502,7 @@ MergeStacksIntoProfile(ThreadInfo& aInfo, TickSample* aSample,
         MOZ_ASSERT(jsFrame.kind == JS::ProfilingFrameIterator::Frame_Ion ||
                    jsFrame.kind == JS::ProfilingFrameIterator::Frame_Baseline);
         aInfo.addTag(
-          ProfileEntry::JitReturnAddr(jsFrames[jsIndex].returnAddress));
+          ProfileBufferEntry::JitReturnAddr(jsFrames[jsIndex].returnAddress));
       }
 
       jsIndex--;
@@ -514,7 +514,7 @@ MergeStacksIntoProfile(ThreadInfo& aInfo, TickSample* aSample,
     if (nativeStackAddr) {
       MOZ_ASSERT(nativeIndex >= 0);
       void* addr = (void*)aNativeStack.pc_array[nativeIndex];
-      aInfo.addTag(ProfileEntry::NativeLeafAddr(addr));
+      aInfo.addTag(ProfileBufferEntry::NativeLeafAddr(addr));
     }
     if (nativeIndex >= 0) {
       nativeIndex--;
@@ -616,7 +616,7 @@ DoNativeBacktrace(ThreadInfo& aInfo, TickSample* aSample)
   for (uint32_t i = pseudoStack->stackSize(); i > 0; --i) {
     // The pseudostack grows towards higher indices, so we iterate
     // backwards (from callee to caller).
-    volatile StackEntry& entry = pseudoStack->mStack[i - 1];
+    volatile js::ProfileEntry& entry = pseudoStack->mStack[i - 1];
     if (!entry.isJs() && strcmp(entry.label(), "EnterJIT") == 0) {
       // Found JIT entry frame.  Unwind up to that point (i.e., force
       // the stack walk to stop before the block of saved registers;
@@ -772,7 +772,7 @@ DoSampleStackTrace(ThreadInfo& aInfo, TickSample* aSample,
   MergeStacksIntoProfile(aInfo, aSample, nativeStack);
 
   if (aSample && aAddLeafAddresses) {
-    aInfo.addTag(ProfileEntry::NativeLeafAddr((void*)aSample->pc));
+    aInfo.addTag(ProfileBufferEntry::NativeLeafAddr((void*)aSample->pc));
   }
 }
 
@@ -783,10 +783,11 @@ Tick(TickSample* aSample)
 {
   ThreadInfo& currThreadInfo = *aSample->threadInfo;
 
-  currThreadInfo.addTag(ProfileEntry::ThreadId(currThreadInfo.ThreadId()));
+  currThreadInfo.addTag(
+    ProfileBufferEntry::ThreadId(currThreadInfo.ThreadId()));
 
   mozilla::TimeDuration delta = aSample->timestamp - gStartTime;
-  currThreadInfo.addTag(ProfileEntry::Time(delta.ToMilliseconds()));
+  currThreadInfo.addTag(ProfileBufferEntry::Time(delta.ToMilliseconds()));
 
   PseudoStack* stack = currThreadInfo.Stack();
 
@@ -808,7 +809,7 @@ Tick(TickSample* aSample)
     while (pendingMarkersList && pendingMarkersList->peek()) {
       ProfilerMarker* marker = pendingMarkersList->popHead();
       currThreadInfo.addStoredMarker(marker);
-      currThreadInfo.addTag(ProfileEntry::Marker(marker));
+      currThreadInfo.addTag(ProfileBufferEntry::Marker(marker));
     }
   }
 
@@ -816,23 +817,24 @@ Tick(TickSample* aSample)
     mozilla::TimeDuration delta =
       currThreadInfo.GetThreadResponsiveness()->GetUnresponsiveDuration(
         aSample->timestamp);
-    currThreadInfo.addTag(ProfileEntry::Responsiveness(delta.ToMilliseconds()));
+    currThreadInfo.addTag(
+      ProfileBufferEntry::Responsiveness(delta.ToMilliseconds()));
   }
 
   // rssMemory is equal to 0 when we are not recording.
   if (aSample->rssMemory != 0) {
-    currThreadInfo.addTag(ProfileEntry::ResidentMemory(
+    currThreadInfo.addTag(ProfileBufferEntry::ResidentMemory(
       static_cast<double>(aSample->rssMemory)));
   }
 
   // ussMemory is equal to 0 when we are not recording.
   if (aSample->ussMemory != 0) {
-    currThreadInfo.addTag(ProfileEntry::UnsharedMemory(
+    currThreadInfo.addTag(ProfileBufferEntry::UnsharedMemory(
       static_cast<double>(aSample->ussMemory)));
   }
 
   if (gLastFrameNumber != gFrameNumber) {
-    currThreadInfo.addTag(ProfileEntry::FrameNumber(gFrameNumber));
+    currThreadInfo.addTag(ProfileBufferEntry::FrameNumber(gFrameNumber));
     gLastFrameNumber = gFrameNumber;
   }
 }
@@ -1233,9 +1235,7 @@ void ProfilerMarker::StreamJSON(SpliceableJSONWriter& aWriter,
 }
 
 // Verbosity control for the profiler.  The aim is to check env var
-// MOZ_PROFILER_VERBOSE only once.  However, we may need to temporarily
-// override that so as to print the profiler's help message.  That's
-// what profiler_set_verbosity is for.
+// MOZ_PROFILER_VERBOSE only once.
 
 enum class Verbosity : int8_t { UNCHECKED, NOTVERBOSE, VERBOSE };
 
@@ -1247,21 +1247,13 @@ profiler_verbose()
 {
   if (gVerbosity == Verbosity::UNCHECKED) {
     gVerbosity = getenv("MOZ_PROFILER_VERBOSE")
-                       ? Verbosity::VERBOSE
-                       : Verbosity::NOTVERBOSE;
+               ? Verbosity::VERBOSE
+               : Verbosity::NOTVERBOSE;
   }
 
   return gVerbosity == Verbosity::VERBOSE;
 }
 
-static void
-profiler_set_verbosity(Verbosity aPv)
-{
-  MOZ_ASSERT(aPv == Verbosity::UNCHECKED ||
-             aPv == Verbosity::VERBOSE);
-  gVerbosity = aPv;
-}
-
 static bool
 set_profiler_interval(const char* aInterval)
 {
@@ -1269,7 +1261,7 @@ set_profiler_interval(const char* aInterval)
     errno = 0;
     long int n = strtol(aInterval, nullptr, 10);
     if (errno == 0 && 1 <= n && n <= 1000) {
-      gUnwindInterval = n;
+      gEnvVarInterval = n;
       return true;
     }
     return false;
@@ -1285,7 +1277,7 @@ set_profiler_entries(const char* aEntries)
     errno = 0;
     long int n = strtol(aEntries, nullptr, 10);
     if (errno == 0 && n > 0) {
-      gProfileEntries = n;
+      gEnvVarEntries = n;
       return true;
     }
     return false;
@@ -1304,84 +1296,63 @@ is_native_unwinding_avail()
 #endif
 }
 
-// Environment variables to control the profiler
-static const char* PROFILER_HELP     = "MOZ_PROFILER_HELP";
-static const char* PROFILER_INTERVAL = "MOZ_PROFILER_INTERVAL";
-static const char* PROFILER_ENTRIES  = "MOZ_PROFILER_ENTRIES";
-#if defined(GP_OS_android)
-static const char* PROFILER_FEATURES = "MOZ_PROFILING_FEATURES";
-#endif
-
 static void
-profiler_usage()
+profiler_usage(int aExitCode)
 {
-  LOG( "Profiler: ");
-  LOG( "Profiler: Environment variable usage:");
-  LOG( "Profiler: ");
-  LOG( "Profiler:   MOZ_PROFILER_HELP");
-  LOG( "Profiler:   If set to any value, prints this message.");
-  LOG( "Profiler: ");
-  LOG( "Profiler:   MOZ_PROFILER_INTERVAL=<number>   (milliseconds, 1 to 1000)");
-  LOG( "Profiler:   If unset, platform default is used.");
-  LOG( "Profiler: ");
-  LOG( "Profiler:   MOZ_PROFILER_ENTRIES=<number>    (count, minimum of 1)");
-  LOG( "Profiler:   If unset, platform default is used.");
-  LOG( "Profiler: ");
-  LOG( "Profiler:   MOZ_PROFILER_VERBOSE");
-  LOG( "Profiler:   If set to any value, increases verbosity (recommended).");
-  LOG( "Profiler: ");
-  LOG( "Profiler:   MOZ_PROFILER_LUL_TEST");
-  LOG( "Profiler:   If set to any value, runs LUL unit tests at startup of");
-  LOG( "Profiler:   the unwinder thread, and prints a short summary of results.");
-  LOG( "Profiler: ");
-  LOGF("Profiler:   This platform %s native unwinding.",
+  // Force-enable verbosity so that LOG prints something.
+  gVerbosity = Verbosity::VERBOSE;
+
+  LOG ("");
+  LOG ("Environment variable usage:");
+  LOG ("");
+  LOG ("  MOZ_PROFILER_HELP");
+  LOG ("  If set to any value, prints this message.");
+  LOG ("");
+  LOG ("  MOZ_PROFILER_ENTRIES=<1..>      (count)");
+  LOG ("  If unset, platform default is used.");
+  LOG ("");
+  LOG ("  MOZ_PROFILER_INTERVAL=<1..1000> (milliseconds)");
+  LOG ("  If unset, platform default is used.");
+  LOG ("");
+  LOG ("  MOZ_PROFILER_VERBOSE");
+  LOG ("  If set to any value, increases verbosity (recommended).");
+  LOG ("");
+  LOG ("  MOZ_PROFILER_LUL_TEST");
+  LOG ("  If set to any value, runs LUL unit tests at startup of");
+  LOG ("  the unwinder thread, and prints a short summary of ");
+  LOG ("  results.");
+  LOG ("");
+  LOGF("  This platform %s native unwinding.",
        is_native_unwinding_avail() ? "supports" : "does not support");
-  LOG( "Profiler: ");
+  LOG ("");
 
-  /* Re-set defaults */
-  gUnwindInterval   = 0;  /* We'll have to look elsewhere */
-  gProfileEntries   = 0;
-
-  LOG( "Profiler:");
-  LOGF("Profiler: Sampling interval = %d ms (zero means \"platform default\")",
-       (int)gUnwindInterval);
-  LOGF("Profiler: Entry store size  = %d (zero means \"platform default\")",
-       (int)gProfileEntries);
-  LOG( "Profiler:");
+  exit(aExitCode);
 }
 
 // Read env vars at startup, so as to set:
-//   gUnwindInterval, gProfileEntries
+//   gEnvVarEntries, gEnvVarInterval
 static void
-read_profiler_env_vars()
+ReadProfilerEnvVars()
 {
-  /* Set defaults */
-  gUnwindInterval = 0;  /* We'll have to look elsewhere */
-  gProfileEntries = 0;
+  const char* help     = getenv("MOZ_PROFILER_HELP");
+  const char* entries  = getenv("MOZ_PROFILER_ENTRIES");
+  const char* interval = getenv("MOZ_PROFILER_INTERVAL");
 
-  const char* interval = getenv(PROFILER_INTERVAL);
-  const char* entries = getenv(PROFILER_ENTRIES);
-
-  if (getenv(PROFILER_HELP)) {
-    // Enable verbose output
-    profiler_set_verbosity(Verbosity::VERBOSE);
-    profiler_usage();
-    // Now force the next enquiry of profiler_verbose to re-query
-    // env var MOZ_PROFILER_VERBOSE.
-    profiler_set_verbosity(Verbosity::UNCHECKED);
+  if (help) {
+    profiler_usage(0); // terminates execution
   }
 
-  if (!set_profiler_interval(interval) ||
-      !set_profiler_entries(entries)) {
-      profiler_usage();
-  } else {
-    LOG( "Profiler:");
-    LOGF("Profiler: Sampling interval = %d ms (zero means \"platform default\")",
-        (int)gUnwindInterval);
-    LOGF("Profiler: Entry store size  = %d (zero means \"platform default\")",
-        (int)gProfileEntries);
-    LOG( "Profiler:");
+  if (!set_profiler_entries(entries) ||
+      !set_profiler_interval(interval)) {
+    profiler_usage(1); // terminates execution
   }
+
+  LOG ("");
+  LOGF("entries  = %d (zero means \"platform default\")",
+       gEnvVarEntries);
+  LOGF("interval = %d ms (zero means \"platform default\")",
+       gEnvVarInterval);
+  LOG ("");
 }
 
 static bool
@@ -1600,7 +1571,7 @@ profiler_init(void* stackTop)
   RegisterCurrentThread(gGeckoThreadName, stack, isMainThread, stackTop);
 
   // Read settings from environment variables.
-  read_profiler_env_vars();
+  ReadProfilerEnvVars();
 
   // Platform-specific initialization.
   PlatformInit();
@@ -1632,7 +1603,7 @@ profiler_init(void* stackTop)
 
   const char* threadFilters[] = { "GeckoMain", "Compositor" };
 
-  profiler_start(PROFILE_DEFAULT_ENTRY, PROFILE_DEFAULT_INTERVAL,
+  profiler_start(PROFILE_DEFAULT_ENTRIES, PROFILE_DEFAULT_INTERVAL,
                  features, MOZ_ARRAY_LENGTH(features),
                  threadFilters, MOZ_ARRAY_LENGTH(threadFilters));
   LOG("END   profiler_init");
@@ -1752,19 +1723,18 @@ profiler_save_profile_to_file_async(double aSinceTime, const char* aFileName)
 }
 
 void
-profiler_get_start_params(int* aEntrySize,
-                          double* aInterval,
+profiler_get_start_params(int* aEntries, double* aInterval,
                           mozilla::Vector<const char*>* aFilters,
                           mozilla::Vector<const char*>* aFeatures)
 {
   MOZ_RELEASE_ASSERT(NS_IsMainThread());
 
-  if (NS_WARN_IF(!aEntrySize) || NS_WARN_IF(!aInterval) ||
+  if (NS_WARN_IF(!aEntries) || NS_WARN_IF(!aInterval) ||
       NS_WARN_IF(!aFilters) || NS_WARN_IF(!aFeatures)) {
     return;
   }
 
-  *aEntrySize = gEntrySize;
+  *aEntries = gEntries;
   *aInterval = gInterval;
 
   {
@@ -1886,9 +1856,9 @@ profiler_get_features()
 }
 
 void
-profiler_get_buffer_info_helper(uint32_t *aCurrentPosition,
-                                uint32_t *aTotalSize,
-                                uint32_t *aGeneration)
+profiler_get_buffer_info_helper(uint32_t* aCurrentPosition,
+                                uint32_t* aEntries,
+                                uint32_t* aGeneration)
 {
   // This function is called by profiler_get_buffer_info(), which has already
   // zeroed the outparams.
@@ -1903,7 +1873,7 @@ profiler_get_buffer_info_helper(uint32_t *aCurrentPosition,
   }
 
   *aCurrentPosition = gBuffer->mWritePos;
-  *aTotalSize = gEntrySize;
+  *aEntries = gEntries;
   *aGeneration = gBuffer->mGeneration;
 }
 
@@ -1923,7 +1893,7 @@ class Sampler {};
 
 // Values are only honored on the first start
 void
-profiler_start(int aProfileEntries, double aInterval,
+profiler_start(int aEntries, double aInterval,
                const char** aFeatures, uint32_t aFeatureCount,
                const char** aThreadNameFilters, uint32_t aFilterCount)
 
@@ -1937,12 +1907,12 @@ profiler_start(int aProfileEntries, double aInterval,
 
   /* If the sampling interval was set using env vars, use that
      in preference to anything else. */
-  if (gUnwindInterval > 0)
-    aInterval = gUnwindInterval;
+  if (gEnvVarInterval > 0)
+    aInterval = gEnvVarInterval;
 
   /* If the entry count was set using env vars, use that, too: */
-  if (gProfileEntries > 0)
-    aProfileEntries = gProfileEntries;
+  if (gEnvVarEntries > 0)
+    aEntries = gEnvVarEntries;
 
   // Reset the current state if the profiler is running
   profiler_stop();
@@ -1987,9 +1957,9 @@ profiler_start(int aProfileEntries, double aInterval,
                       aFilterCount > 0;
   gUseStackWalk     = hasFeature(aFeatures, aFeatureCount, "stackwalk");
 
-  gEntrySize = aProfileEntries ? aProfileEntries : PROFILE_DEFAULT_ENTRY;
+  gEntries = aEntries ? aEntries : PROFILE_DEFAULT_ENTRIES;
   gInterval = aInterval ? aInterval : PROFILE_DEFAULT_INTERVAL;
-  gBuffer = new ProfileBuffer(gEntrySize);
+  gBuffer = new ProfileBuffer(gEntries);
   gSampler = new Sampler();
 
   bool ignore;
@@ -2073,7 +2043,7 @@ profiler_start(int aProfileEntries, double aInterval,
       }
 
       nsCOMPtr<nsIProfilerStartParams> params =
-        new nsProfilerStartParams(aProfileEntries, aInterval, featuresArray,
+        new nsProfilerStartParams(aEntries, aInterval, featuresArray,
                                   threadNameFiltersArray);
 
       os->NotifyObservers(params, "profiler-started", nullptr);
@@ -2150,7 +2120,7 @@ profiler_stop()
   delete gSampler;
   gSampler = nullptr;
   gBuffer = nullptr;
-  gEntrySize = 0;
+  gEntries = 0;
   gInterval = 0;
 
   // Cancel any in-flight async profile gatherering requests.
@@ -2518,7 +2488,7 @@ profiler_get_backtrace_noalloc(char *output, size_t outputSize)
     return;
   }
 
-  volatile StackEntry *pseudoFrames = pseudoStack->mStack;
+  volatile js::ProfileEntry *pseudoFrames = pseudoStack->mStack;
   uint32_t pseudoCount = pseudoStack->stackSize();
 
   for (uint32_t i = 0; i < pseudoCount; i++) {
diff --git a/tools/profiler/gecko/ThreadResponsiveness.cpp b/tools/profiler/gecko/ThreadResponsiveness.cpp
index 6d2d7e0025de..b7e317e6abc8 100644
--- a/tools/profiler/gecko/ThreadResponsiveness.cpp
+++ b/tools/profiler/gecko/ThreadResponsiveness.cpp
@@ -9,7 +9,6 @@
 #include "nsThreadUtils.h"
 #include "nsITimer.h"
 #include "mozilla/Monitor.h"
-#include "ProfileEntry.h"
 
 using mozilla::Monitor;
 using mozilla::MonitorAutoLock;
diff --git a/tools/profiler/gecko/nsProfiler.cpp b/tools/profiler/gecko/nsProfiler.cpp
index 582a26e12aa7..fb6c0d306fb9 100644
--- a/tools/profiler/gecko/nsProfiler.cpp
+++ b/tools/profiler/gecko/nsProfiler.cpp
@@ -280,7 +280,8 @@ nsProfiler::GetStartParams(nsIProfilerStartParams** aRetVal)
 }
 
 NS_IMETHODIMP
-nsProfiler::GetBufferInfo(uint32_t *aCurrentPosition, uint32_t *aTotalSize, uint32_t *aGeneration)
+nsProfiler::GetBufferInfo(uint32_t* aCurrentPosition, uint32_t* aTotalSize,
+                          uint32_t* aGeneration)
 {
   MOZ_ASSERT(aCurrentPosition);
   MOZ_ASSERT(aTotalSize);
diff --git a/tools/profiler/moz.build b/tools/profiler/moz.build
index 5b83893a4ab6..cc85bb43706e 100644
--- a/tools/profiler/moz.build
+++ b/tools/profiler/moz.build
@@ -22,7 +22,7 @@ if CONFIG['MOZ_GECKO_PROFILER']:
     UNIFIED_SOURCES += [
         'core/platform.cpp',
         'core/ProfileBuffer.cpp',
-        'core/ProfileEntry.cpp',
+        'core/ProfileBufferEntry.cpp',
         'core/ProfileJSONWriter.cpp',
         'core/ProfilerBacktrace.cpp',
         'core/ProfilerMarkers.cpp',
diff --git a/tools/profiler/public/GeckoProfiler.h b/tools/profiler/public/GeckoProfiler.h
index 49effd3fe5fc..14c3247d7bd3 100644
--- a/tools/profiler/public/GeckoProfiler.h
+++ b/tools/profiler/public/GeckoProfiler.h
@@ -161,15 +161,17 @@ PROFILER_FUNC_VOID(profiler_shutdown())
 
 // Start the profiler with the selected options. The samples will be
 // recorded in a circular buffer.
-//   "aProfileEntries" is an abstract size indication of how big
+//   "aEntries" is an abstract size indication of how big
 //       the profile's circular buffer should be. Multiply by 4
 //       words to get the cost.
 //   "aInterval" the sampling interval. The profiler will do its
 //       best to sample at this interval. The profiler visualization
 //       should represent the actual sampling accuracy.
-PROFILER_FUNC_VOID(profiler_start(int aProfileEntries, double aInterval,
-                              const char** aFeatures, uint32_t aFeatureCount,
-                              const char** aThreadNameFilters, uint32_t aFilterCount))
+PROFILER_FUNC_VOID(profiler_start(int aEntries, double aInterval,
+                                  const char** aFeatures,
+                                  uint32_t aFeatureCount,
+                                  const char** aThreadNameFilters,
+                                  uint32_t aFilterCount))
 
 // Stop the profiler and discard the profile. Call 'profiler_save' before this
 // to retrieve the profile.
@@ -234,7 +236,7 @@ PROFILER_FUNC_VOID(profiler_save_profile_to_file(const char* aFilename))
 PROFILER_FUNC(const char** profiler_get_features(), nullptr)
 
 PROFILER_FUNC_VOID(profiler_get_buffer_info_helper(uint32_t* aCurrentPosition,
-                                                   uint32_t* aTotalSize,
+                                                   uint32_t* aEntries,
                                                    uint32_t* aGeneration))
 
 // Get information about the current buffer status.
@@ -245,14 +247,14 @@ PROFILER_FUNC_VOID(profiler_get_buffer_info_helper(uint32_t* aCurrentPosition,
 // for how fast the buffer is being written to, and how much
 // data is visible.
 static inline void profiler_get_buffer_info(uint32_t* aCurrentPosition,
-                                            uint32_t* aTotalSize,
+                                            uint32_t* aEntries,
                                             uint32_t* aGeneration)
 {
   *aCurrentPosition = 0;
-  *aTotalSize = 0;
+  *aEntries = 0;
   *aGeneration = 0;
 
-  profiler_get_buffer_info_helper(aCurrentPosition, aTotalSize, aGeneration);
+  profiler_get_buffer_info_helper(aCurrentPosition, aEntries, aGeneration);
 }
 
 // Lock the profiler. When locked the profiler is (1) stopped,
@@ -433,14 +435,14 @@ void profiler_OOP_exit_profile(const nsCString& aProfile);
 #endif
 
 #if !defined(PLATFORM_LIKELY_MEMORY_CONSTRAINED) && !defined(ARCH_ARMV6)
-# define PROFILE_DEFAULT_ENTRY 1000000
+# define PROFILE_DEFAULT_ENTRIES 1000000
 #else
-# define PROFILE_DEFAULT_ENTRY 100000
+# define PROFILE_DEFAULT_ENTRIES 100000
 #endif
 
 // In the case of profiler_get_backtrace we know that we only need enough space
 // for a single backtrace.
-#define GET_BACKTRACE_DEFAULT_ENTRY 1000
+#define GET_BACKTRACE_DEFAULT_ENTRIES 1000
 
 #if defined(PLATFORM_LIKELY_MEMORY_CONSTRAINED)
 /* A 1ms sampling interval has been shown to be a large perf hit
diff --git a/tools/profiler/public/PseudoStack.h b/tools/profiler/public/PseudoStack.h
index cabeabe17f9d..c5e8765401cf 100644
--- a/tools/profiler/public/PseudoStack.h
+++ b/tools/profiler/public/PseudoStack.h
@@ -49,18 +49,6 @@ LinuxKernelMemoryBarrierFunc pLinuxKernelMemoryBarrier __attribute__((weak)) =
 # error "Memory clobber not supported for your platform."
 #endif
 
-// A stack entry exists to allow the JS engine to inform the Gecko Profiler of
-// the current backtrace, but also to instrument particular points in C++ in
-// case stack walking is not available on the platform we are running on.
-//
-// Each entry has a descriptive string, a relevant stack address, and some extra
-// information the JS engine might want to inform the Gecko Profiler of. This
-// class inherits from the JS engine's version of the entry to ensure that the
-// size and layout of the two representations are consistent.
-class StackEntry : public js::ProfileEntry
-{
-};
-
 class ProfilerMarkerPayload;
 template<typename T>
 class ProfilerLinkedList;
@@ -273,7 +261,7 @@ public:
       return;
     }
 
-    volatile StackEntry& entry = mStack[mStackPointer];
+    volatile js::ProfileEntry& entry = mStack[mStackPointer];
 
     // Make sure we increment the pointer after the name has been written such
     // that mStack is always consistent.
@@ -412,7 +400,7 @@ private:
 
 public:
   // The list of active checkpoints.
-  StackEntry volatile mStack[1024];
+  js::ProfileEntry volatile mStack[1024];
 
 private:
   // A list of pending markers that must be moved to the circular buffer.
diff --git a/tools/profiler/tasktracer/GeckoTaskTracer.cpp b/tools/profiler/tasktracer/GeckoTaskTracer.cpp
index ed320e7b635f..5a0acd916c3a 100644
--- a/tools/profiler/tasktracer/GeckoTaskTracer.cpp
+++ b/tools/profiler/tasktracer/GeckoTaskTracer.cpp
@@ -57,7 +57,7 @@ static mozilla::StaticMutex sMutex;
 
 // The generation of TraceInfo. It will be > 0 if the Task Tracer is started and
 // <= 0 if stopped.
-static mozilla::Atomic<bool> sStarted;
+static mozilla::Atomic<bool> sStarted(false);
 static nsTArray<UniquePtr<TraceInfo>>* sTraceInfos = nullptr;
 static PRTime sStartTime;
 
@@ -74,8 +74,8 @@ GetTimestamp()
 static TraceInfo*
 AllocTraceInfo(int aTid)
 {
-  StaticMutexAutoLock lock(sMutex);
-
+  sMutex.AssertCurrentThreadOwns();
+  MOZ_ASSERT(sTraceInfos);
   auto* info = sTraceInfos->AppendElement(MakeUnique<TraceInfo>(aTid));
 
   return info->get();
@@ -86,12 +86,14 @@ CreateSourceEvent(SourceEventType aType)
 {
   // Create a new unique task id.
   uint64_t newId = GenNewUniqueTaskId();
-  TraceInfo* info = GetOrCreateTraceInfo();
-  ENSURE_TRUE_VOID(info);
+  {
+    TraceInfoHolder info = GetOrCreateTraceInfo();
+    ENSURE_TRUE_VOID(info);
 
-  info->mCurTraceSourceId = newId;
-  info->mCurTraceSourceType = aType;
-  info->mCurTaskId = newId;
+    info->mCurTraceSourceId = newId;
+    info->mCurTraceSourceType = aType;
+    info->mCurTaskId = newId;
+  }
 
   uintptr_t* namePtr;
 #define SOURCE_EVENT_NAME(type)         \
@@ -118,10 +120,23 @@ static void
 DestroySourceEvent()
 {
   // Log a fake end for this source event.
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
-  LogEnd(info->mCurTraceSourceId, info->mCurTraceSourceId);
+  uint64_t curTraceSourceId;
+  curTraceSourceId = info->mCurTraceSourceId;
+  info.Reset();
+
+  LogEnd(curTraceSourceId, curTraceSourceId);
+}
+
+inline static void
+ObsoleteCurrentTraceInfos()
+{
+  MOZ_ASSERT(sTraceInfos);
+  for (uint32_t i = 0; i < sTraceInfos->Length(); ++i) {
+    (*sTraceInfos)[i]->mObsolete = true;
+  }
 }
 
 inline static bool
@@ -134,24 +149,16 @@ static void
 SetLogStarted(bool aIsStartLogging)
 {
   MOZ_ASSERT(aIsStartLogging != sStarted);
-  MOZ_ASSERT(sTraceInfos != nullptr);
+  StaticMutexAutoLock lock(sMutex);
+
   sStarted = aIsStartLogging;
 
-  StaticMutexAutoLock lock(sMutex);
-  if (!aIsStartLogging && sTraceInfos) {
-    for (uint32_t i = 0; i < sTraceInfos->Length(); ++i) {
-      (*sTraceInfos)[i]->mObsolete = true;
-    }
+  if (aIsStartLogging && sTraceInfos == nullptr) {
+    sTraceInfos = new nsTArray<UniquePtr<TraceInfo>>();
   }
-}
 
-inline static void
-ObsoleteCurrentTraceInfos()
-{
-  // Note that we can't and don't need to acquire sMutex here because this
-  // function is called before the other threads are recreated.
-  for (uint32_t i = 0; i < sTraceInfos->Length(); ++i) {
-    (*sTraceInfos)[i]->mObsolete = true;
+  if (!aIsStartLogging && sTraceInfos) {
+    ObsoleteCurrentTraceInfos();
   }
 }
 
@@ -191,9 +198,6 @@ InitTaskTracer(uint32_t aFlags)
   if (!success) {
     MOZ_CRASH();
   }
-
-  // A memory barrier is necessary here.
-  sTraceInfos = new nsTArray<UniquePtr<TraceInfo>>();
 }
 
 void
@@ -201,13 +205,22 @@ ShutdownTaskTracer()
 {
   if (IsStartLogging()) {
     SetLogStarted(false);
+
+    StaticMutexAutoLock lock(sMutex);
+    // Make sure all threads are out of holding mutics.
+    // See |GetOrCreateTraceInfo()|
+    for (auto& traceinfo: *sTraceInfos) {
+      MutexAutoLock lock(traceinfo->mLogsMutex);
+    }
+    delete sTraceInfos;
+    sTraceInfos = nullptr;
   }
 }
 
 static void
 FreeTraceInfo(TraceInfo* aTraceInfo)
 {
-  StaticMutexAutoLock lock(sMutex);
+  sMutex.AssertCurrentThreadOwns();
   if (aTraceInfo) {
     UniquePtr<TraceInfo> traceinfo(aTraceInfo);
     mozilla::DebugOnly<bool> removed =
@@ -219,15 +232,19 @@ FreeTraceInfo(TraceInfo* aTraceInfo)
 
 void FreeTraceInfo()
 {
-  FreeTraceInfo(sTraceInfoTLS.get());
+  StaticMutexAutoLock lock(sMutex);
+  if (sTraceInfos) {
+    FreeTraceInfo(sTraceInfoTLS.get());
+  }
 }
 
-TraceInfo*
+TraceInfoHolder
 GetOrCreateTraceInfo()
 {
-  ENSURE_TRUE(IsStartLogging(), nullptr);
-
   TraceInfo* info = sTraceInfoTLS.get();
+  StaticMutexAutoLock lock(sMutex);
+  ENSURE_TRUE(IsStartLogging(), TraceInfoHolder{});
+
   if (info && info->mObsolete) {
     // TraceInfo is obsolete: remove it.
     FreeTraceInfo(info);
@@ -239,13 +256,15 @@ GetOrCreateTraceInfo()
     sTraceInfoTLS.set(info);
   }
 
-  return info;
+  return TraceInfoHolder{info}; // |mLogsMutex| will be held, then
+                                // ||sMutex| will be released for
+                                // efficiency reason.
 }
 
 uint64_t
 GenNewUniqueTaskId()
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE(info, 0);
 
   Thread::tid_t tid = Thread::GetCurrentId();
@@ -267,7 +286,7 @@ void
 SetCurTraceInfo(uint64_t aSourceEventId, uint64_t aParentTaskId,
                 SourceEventType aSourceEventType)
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
   info->mCurTraceSourceId = aSourceEventId;
@@ -279,7 +298,7 @@ void
 GetCurTraceInfo(uint64_t* aOutSourceEventId, uint64_t* aOutParentTaskId,
                 SourceEventType* aOutSourceEventType)
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
   *aOutSourceEventId = info->mCurTraceSourceId;
@@ -298,7 +317,7 @@ void
 LogDispatch(uint64_t aTaskId, uint64_t aParentTaskId, uint64_t aSourceEventId,
             SourceEventType aSourceEventType, int aDelayTimeMs)
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
   // aDelayTimeMs is the expected delay time in milliseconds, thus the dispatch
@@ -306,7 +325,6 @@ LogDispatch(uint64_t aTaskId, uint64_t aParentTaskId, uint64_t aSourceEventId,
   uint64_t time = (aDelayTimeMs <= 0) ? GetTimestamp() :
                   GetTimestamp() + aDelayTimeMs;
 
-  MutexAutoLock lock(info->mLogsMutex);
   // Log format:
   // [0 taskId dispatchTime sourceEventId sourceEventType parentTaskId]
   TraceInfoLogType* log = info->AppendLog();
@@ -323,10 +341,9 @@ LogDispatch(uint64_t aTaskId, uint64_t aParentTaskId, uint64_t aSourceEventId,
 void
 LogBegin(uint64_t aTaskId, uint64_t aSourceEventId)
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
-  MutexAutoLock lock(info->mLogsMutex);
   // Log format:
   // [1 taskId beginTime processId threadId]
   TraceInfoLogType* log = info->AppendLog();
@@ -342,10 +359,9 @@ LogBegin(uint64_t aTaskId, uint64_t aSourceEventId)
 void
 LogEnd(uint64_t aTaskId, uint64_t aSourceEventId)
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
-  MutexAutoLock lock(info->mLogsMutex);
   // Log format:
   // [2 taskId endTime]
   TraceInfoLogType* log = info->AppendLog();
@@ -359,10 +375,9 @@ LogEnd(uint64_t aTaskId, uint64_t aSourceEventId)
 void
 LogVirtualTablePtr(uint64_t aTaskId, uint64_t aSourceEventId, uintptr_t* aVptr)
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
-  MutexAutoLock lock(info->mLogsMutex);
   // Log format:
   // [4 taskId address]
   TraceInfoLogType* log = info->AppendLog();
@@ -412,10 +427,9 @@ AutoScopedLabel::~AutoScopedLabel()
 
 void AddLabel(const char* aFormat, ...)
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
-  MutexAutoLock lock(info->mLogsMutex);
   // Log format:
   // [3 taskId "label"]
   TraceInfoLogType* log = info->AppendLog();
@@ -456,6 +470,10 @@ GetLoggedData(TimeStamp aTimeStamp)
   // TODO: This is called from a signal handler. Use semaphore instead.
   StaticMutexAutoLock lock(sMutex);
 
+  if (sTraceInfos == nullptr) {
+    return result;
+  }
+
   for (uint32_t i = 0; i < sTraceInfos->Length(); ++i) {
     TraceInfo* info = (*sTraceInfos)[i].get();
     MutexAutoLock lockLogs(info->mLogsMutex);
diff --git a/tools/profiler/tasktracer/GeckoTaskTracerImpl.h b/tools/profiler/tasktracer/GeckoTaskTracerImpl.h
index 428d020edbd0..48a9da1287fc 100644
--- a/tools/profiler/tasktracer/GeckoTaskTracerImpl.h
+++ b/tools/profiler/tasktracer/GeckoTaskTracerImpl.h
@@ -107,8 +107,43 @@ struct TraceInfo
   nsTArray<nsCString> mStrs;
 };
 
+class TraceInfoHolder {
+public:
+  TraceInfoHolder() : mInfo(nullptr) {}
+  explicit TraceInfoHolder(TraceInfo* aInfo) : mInfo(aInfo) {
+    aInfo->mLogsMutex.AssertNotCurrentThreadOwns(); // in case of recursive
+    aInfo->mLogsMutex.Lock();
+    MOZ_ASSERT(aInfo);
+  }
+  TraceInfoHolder(const TraceInfoHolder& aOther) = delete;
+  TraceInfoHolder(TraceInfoHolder&& aOther) : mInfo(aOther.mInfo) {
+    if (!!aOther) {
+      aOther->mLogsMutex.AssertCurrentThreadOwns();
+    }
+    aOther.mInfo = nullptr;
+  }
+  ~TraceInfoHolder() { if (mInfo) mInfo->mLogsMutex.Unlock(); }
+  explicit operator bool() const { return !!mInfo; }
+  TraceInfo* operator ->() { return mInfo; }
+  bool operator ==(TraceInfo* aOther) const {
+    return mInfo == aOther;
+  }
+  bool operator ==(const TraceInfoHolder& aOther) const {
+    return mInfo == aOther.mInfo;
+  }
+  void Reset() {
+    if (mInfo) {
+      mInfo->mLogsMutex.Unlock();
+      mInfo = nullptr;
+    }
+  }
+
+private:
+  TraceInfo* mInfo;
+};
+
 // Return the TraceInfo of current thread, allocate a new one if not exit.
-TraceInfo* GetOrCreateTraceInfo();
+TraceInfoHolder GetOrCreateTraceInfo();
 
 uint64_t GenNewUniqueTaskId();
 
diff --git a/tools/profiler/tasktracer/TracedTaskCommon.cpp b/tools/profiler/tasktracer/TracedTaskCommon.cpp
index bc4b4bd4030f..4e8796f8a3c9 100644
--- a/tools/profiler/tasktracer/TracedTaskCommon.cpp
+++ b/tools/profiler/tasktracer/TracedTaskCommon.cpp
@@ -34,7 +34,7 @@ TracedTaskCommon::~TracedTaskCommon()
 void
 TracedTaskCommon::Init()
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
   mTaskId = GenNewUniqueTaskId();
@@ -54,7 +54,7 @@ TracedTaskCommon::DispatchTask(int aDelayTimeMs)
 void
 TracedTaskCommon::GetTLSTraceInfo()
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
   mSourceEventType = info->mCurTraceSourceType;
@@ -66,7 +66,7 @@ TracedTaskCommon::GetTLSTraceInfo()
 void
 TracedTaskCommon::SetTLSTraceInfo()
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
   if (mIsTraceInfoInit) {
@@ -79,7 +79,7 @@ TracedTaskCommon::SetTLSTraceInfo()
 void
 TracedTaskCommon::ClearTLSTraceInfo()
 {
-  TraceInfo* info = GetOrCreateTraceInfo();
+  TraceInfoHolder info = GetOrCreateTraceInfo();
   ENSURE_TRUE_VOID(info);
 
   info->mCurTraceSourceId = 0;
diff --git a/tools/profiler/tests/gtest/ThreadProfileTest.cpp b/tools/profiler/tests/gtest/ThreadProfileTest.cpp
index a7f04bca329e..3c05b813c6ed 100644
--- a/tools/profiler/tests/gtest/ThreadProfileTest.cpp
+++ b/tools/profiler/tests/gtest/ThreadProfileTest.cpp
@@ -5,7 +5,7 @@
 
 #include "gtest/gtest.h"
 
-#include "ProfileEntry.h"
+#include "ProfileBufferEntry.h"
 #include "ThreadInfo.h"
 
 // Make sure we can initialize our thread profile
@@ -23,9 +23,10 @@ TEST(ThreadProfile, InsertOneTag) {
   Thread::tid_t tid = 1000;
   ThreadInfo info("testThread", tid, true, stack, nullptr);
   RefPtr<ProfileBuffer> pb = new ProfileBuffer(10);
-  pb->addTag(ProfileEntry::Time(123.1));
+  pb->addTag(ProfileBufferEntry::Time(123.1));
   ASSERT_TRUE(pb->mEntries != nullptr);
-  ASSERT_TRUE(pb->mEntries[pb->mReadPos].kind() == ProfileEntry::Kind::Time);
+  ASSERT_TRUE(pb->mEntries[pb->mReadPos].kind() ==
+              ProfileBufferEntry::Kind::Time);
   ASSERT_TRUE(pb->mEntries[pb->mReadPos].mTagDouble == 123.1);
 }
 
@@ -37,12 +38,13 @@ TEST(ThreadProfile, InsertTagsNoWrap) {
   RefPtr<ProfileBuffer> pb = new ProfileBuffer(100);
   int test_size = 50;
   for (int i = 0; i < test_size; i++) {
-    pb->addTag(ProfileEntry::Time(i));
+    pb->addTag(ProfileBufferEntry::Time(i));
   }
   ASSERT_TRUE(pb->mEntries != nullptr);
   int readPos = pb->mReadPos;
   while (readPos != pb->mWritePos) {
-    ASSERT_TRUE(pb->mEntries[readPos].kind() == ProfileEntry::Kind::Time);
+    ASSERT_TRUE(pb->mEntries[readPos].kind() ==
+                ProfileBufferEntry::Kind::Time);
     ASSERT_TRUE(pb->mEntries[readPos].mTagDouble == readPos);
     readPos = (readPos + 1) % pb->mEntrySize;
   }
@@ -59,13 +61,14 @@ TEST(ThreadProfile, InsertTagsWrap) {
   RefPtr<ProfileBuffer> pb = new ProfileBuffer(buffer_size);
   int test_size = 43;
   for (int i = 0; i < test_size; i++) {
-    pb->addTag(ProfileEntry::Time(i));
+    pb->addTag(ProfileBufferEntry::Time(i));
   }
   ASSERT_TRUE(pb->mEntries != nullptr);
   int readPos = pb->mReadPos;
   int ctr = 0;
   while (readPos != pb->mWritePos) {
-    ASSERT_TRUE(pb->mEntries[readPos].kind() == ProfileEntry::Kind::Time);
+    ASSERT_TRUE(pb->mEntries[readPos].kind() ==
+                ProfileBufferEntry::Kind::Time);
     // the first few tags were discarded when we wrapped
     ASSERT_TRUE(pb->mEntries[readPos].mTagDouble == ctr + (test_size - tags));
     ctr++;
diff --git a/widget/android/ANRReporter.cpp b/widget/android/ANRReporter.cpp
index 30d9b3d7624d..052299c41366 100644
--- a/widget/android/ANRReporter.cpp
+++ b/widget/android/ANRReporter.cpp
@@ -38,8 +38,10 @@ ANRReporter::RequestNativeStack(bool aUnwind)
     const char *NATIVE_STACK_THREADS[] =
         {"GeckoMain", "Compositor"};
     // Buffer one sample and let the profiler wait a long time
-    profiler_start(100, 10000, features, features_size / sizeof(char*),
-        NATIVE_STACK_THREADS, sizeof(NATIVE_STACK_THREADS) / sizeof(char*));
+    profiler_start(/* entries */ 100, /* interval */ 10000,
+                   features, features_size / sizeof(char*),
+                   NATIVE_STACK_THREADS,
+                   sizeof(NATIVE_STACK_THREADS) / sizeof(char*));
     return true;
 }
 
diff --git a/xpcom/threads/ThreadStackHelper.cpp b/xpcom/threads/ThreadStackHelper.cpp
index 66d1d550adcd..0e2437e8cc6e 100644
--- a/xpcom/threads/ThreadStackHelper.cpp
+++ b/xpcom/threads/ThreadStackHelper.cpp
@@ -426,7 +426,7 @@ GetPathAfterComponent(const char* filename, const char (&component)[LEN]) {
 } // namespace
 
 const char*
-ThreadStackHelper::AppendJSEntry(const volatile StackEntry* aEntry,
+ThreadStackHelper::AppendJSEntry(const volatile js::ProfileEntry* aEntry,
                                  intptr_t& aAvailableBufferSize,
                                  const char* aPrevLabel)
 {
@@ -513,8 +513,8 @@ ThreadStackHelper::FillStackBuffer()
   intptr_t availableBufferSize = intptr_t(reservedBufferSize);
 
   // Go from front to back
-  const volatile StackEntry* entry = mPseudoStack->mStack;
-  const volatile StackEntry* end = entry + mPseudoStack->stackSize();
+  const volatile js::ProfileEntry* entry = mPseudoStack->mStack;
+  const volatile js::ProfileEntry* end = entry + mPseudoStack->stackSize();
   // Deduplicate identical, consecutive frames
   const char* prevLabel = nullptr;
   for (; reservedSize-- && entry != end; entry++) {
diff --git a/xpcom/threads/ThreadStackHelper.h b/xpcom/threads/ThreadStackHelper.h
index 12e9e6487b9d..347f7c0d4c97 100644
--- a/xpcom/threads/ThreadStackHelper.h
+++ b/xpcom/threads/ThreadStackHelper.h
@@ -8,8 +8,7 @@
 #define mozilla_ThreadStackHelper_h
 
 #include "mozilla/ThreadHangStats.h"
-
-#include "GeckoProfiler.h"
+#include "js/ProfilingStack.h"
 
 #include <stddef.h>
 
@@ -79,7 +78,7 @@ private:
   void FillStackBuffer();
   void FillThreadContext(void* aContext = nullptr);
 #ifdef MOZ_THREADSTACKHELPER_PSEUDO
-  const char* AppendJSEntry(const volatile StackEntry* aEntry,
+  const char* AppendJSEntry(const volatile js::ProfileEntry* aEntry,
                             intptr_t& aAvailableBufferSize,
                             const char* aPrevLabel);
 #endif