diff --git a/accessible/windows/msaa/AccessibleWrap.cpp b/accessible/windows/msaa/AccessibleWrap.cpp
index 274da2fc7cad..0f30c0581b5c 100644
--- a/accessible/windows/msaa/AccessibleWrap.cpp
+++ b/accessible/windows/msaa/AccessibleWrap.cpp
@@ -1255,15 +1255,25 @@ AccessibleWrap::GetHWNDFor(Accessible* aAccessible)
     return nullptr;
   }
 
-  // Accessibles in child processes are said to have the HWND of the window
-  // their tab is within.  Popups are always in the parent process, and so
-  // never proxied, which means this is basically correct.
   if (aAccessible->IsProxy()) {
     ProxyAccessible* proxy = aAccessible->Proxy();
     if (!proxy) {
       return nullptr;
     }
 
+    // If window emulation is enabled, retrieve the emulated window from the
+    // containing document document proxy.
+    if (nsWinUtils::IsWindowEmulationStarted()) {
+      DocAccessibleParent* doc = proxy->Document();
+      HWND hWnd = doc->GetEmulatedWindowHandle();
+      if (hWnd) {
+        return hWnd;
+      }
+    }
+
+    // Accessibles in child processes are said to have the HWND of the window
+    // their tab is within.  Popups are always in the parent process, and so
+    // never proxied, which means this is basically correct.
     Accessible* outerDoc = proxy->OuterDocOfRemoteBrowser();
     NS_ASSERTION(outerDoc, "no outer doc for accessible remote tab!");
     if (!outerDoc) {
diff --git a/browser/base/content/test/urlbar/browser.ini b/browser/base/content/test/urlbar/browser.ini
index 7e013fdd0044..9d11f931fdce 100644
--- a/browser/base/content/test/urlbar/browser.ini
+++ b/browser/base/content/test/urlbar/browser.ini
@@ -29,7 +29,6 @@ support-files =
 [browser_bug556061.js]
 subsuite = clipboard
 [browser_bug562649.js]
-skip-if = e10s # Bug 1315042
 [browser_bug623155.js]
 support-files =
   redirect_bug623155.sjs
diff --git a/browser/base/content/test/urlbar/browser_bug562649.js b/browser/base/content/test/urlbar/browser_bug562649.js
index 32870133d923..f56e430ee99d 100644
--- a/browser/base/content/test/urlbar/browser_bug562649.js
+++ b/browser/base/content/test/urlbar/browser_bug562649.js
@@ -9,7 +9,7 @@ function test() {
   is(gURLBar.value, URI, "location bar value matches test URI");
 
   gBrowser.selectedTab = gBrowser.addTab();
-  gBrowser.removeCurrentTab();
+  gBrowser.removeCurrentTab({ skipPermitUnload: true });
   is(gBrowser.userTypedValue, URI, "userTypedValue matches test URI after switching tabs");
   is(gURLBar.value, URI, "location bar value matches test URI after switching tabs");
 
@@ -18,7 +18,7 @@ function test() {
     is(gBrowser.userTypedValue, null, "userTypedValue is null as the page has loaded");
     is(gURLBar.value, URI, "location bar value matches test URI as the page has loaded");
 
-    gBrowser.removeCurrentTab();
+    gBrowser.removeCurrentTab({ skipPermitUnload: true });
     finish();
   });
 }
diff --git a/devtools/client/framework/options-panel.css b/devtools/client/framework/options-panel.css
index 0a4ac8c4a33e..dea0def4f56d 100644
--- a/devtools/client/framework/options-panel.css
+++ b/devtools/client/framework/options-panel.css
@@ -110,7 +110,12 @@
   min-width: 80px;
 }
 
+#screenshot-icon {
+  vertical-align: middle;
+  min-width: 0;
+  padding: 5px;
+}
+
 #screenshot-icon::before {
   background-image: url(chrome://devtools/skin/images/command-screenshot.svg);
-  margin-inline-start: 5px;
 }
diff --git a/devtools/client/framework/toolbox-options.xhtml b/devtools/client/framework/toolbox-options.xhtml
index ba1ebde77a25..d0a5c4eadad7 100644
--- a/devtools/client/framework/toolbox-options.xhtml
+++ b/devtools/client/framework/toolbox-options.xhtml
@@ -110,7 +110,7 @@
 
       <fieldset id="screenshot-options" class="options-groupbox">
         <legend>&options.screenshot.label;
-          <span id="screenshot-icon" class="devtools-button"></span>
+          <button id="screenshot-icon" disabled="true" class="devtools-button"></button>
         </legend>
         <label title="&options.screenshot.clipboard.tooltip;">
           <input type="checkbox"
diff --git a/dom/base/crashtests/crashtests.list b/dom/base/crashtests/crashtests.list
index 46d20112db94..25da90e2cd3e 100644
--- a/dom/base/crashtests/crashtests.list
+++ b/dom/base/crashtests/crashtests.list
@@ -168,8 +168,8 @@ load 824719.html
 load 827190.html
 load 828054.html
 load 828903.html
-asserts-if(stylo,2) load 829428.html # bug 1324669
-asserts-if(stylo,2) load 830098.html # bug 1324669
+load 829428.html
+load 830098.html
 load 831287.html
 load 832644.html
 load 836890.html
diff --git a/dom/canvas/CanvasRenderingContext2D.cpp b/dom/canvas/CanvasRenderingContext2D.cpp
index 3cb831ffdab9..62d36c73d8f8 100644
--- a/dom/canvas/CanvasRenderingContext2D.cpp
+++ b/dom/canvas/CanvasRenderingContext2D.cpp
@@ -5610,69 +5610,72 @@ CanvasRenderingContext2D::GetImageDataArray(JSContext* aCx,
   IntRect dstWriteRect = srcReadRect;
   dstWriteRect.MoveBy(-aX, -aY);
 
-  JS::AutoCheckCannotGC nogc;
-  bool isShared;
-  uint8_t* data = JS_GetUint8ClampedArrayData(darray, &isShared, nogc);
-  MOZ_ASSERT(!isShared);        // Should not happen, data was created above
+  {
+    JS::AutoCheckCannotGC nogc;
+    bool isShared;
+    uint8_t* data = JS_GetUint8ClampedArrayData(darray, &isShared, nogc);
+    MOZ_ASSERT(!isShared);        // Should not happen, data was created above
 
-  uint8_t* src;
-  uint32_t srcStride;
-  if (readback) {
-    srcStride = rawData.mStride;
-    src = rawData.mData + srcReadRect.y * srcStride + srcReadRect.x * 4;
-  } else {
-    src = data;
-    srcStride = aWidth * 4;
-  }
+    uint8_t* src;
+    uint32_t srcStride;
+    if (readback) {
+      srcStride = rawData.mStride;
+      src = rawData.mData + srcReadRect.y * srcStride + srcReadRect.x * 4;
+    } else {
+      src = data;
+      srcStride = aWidth * 4;
+    }
 
-  uint8_t* dst = data + dstWriteRect.y * (aWidth * 4) + dstWriteRect.x * 4;
+    uint8_t* dst = data + dstWriteRect.y * (aWidth * 4) + dstWriteRect.x * 4;
 
-  if (mOpaque) {
-    for (int32_t j = 0; j < dstWriteRect.height; ++j) {
-      for (int32_t i = 0; i < dstWriteRect.width; ++i) {
-        // XXX Is there some useful swizzle MMX we can use here?
+    if (mOpaque) {
+      for (int32_t j = 0; j < dstWriteRect.height; ++j) {
+        for (int32_t i = 0; i < dstWriteRect.width; ++i) {
+          // XXX Is there some useful swizzle MMX we can use here?
 #if MOZ_LITTLE_ENDIAN
-        uint8_t b = *src++;
-        uint8_t g = *src++;
-        uint8_t r = *src++;
-        src++;
+          uint8_t b = *src++;
+          uint8_t g = *src++;
+          uint8_t r = *src++;
+          src++;
 #else
-        src++;
-        uint8_t r = *src++;
-        uint8_t g = *src++;
-        uint8_t b = *src++;
+          src++;
+          uint8_t r = *src++;
+          uint8_t g = *src++;
+          uint8_t b = *src++;
 #endif
-        *dst++ = r;
-        *dst++ = g;
-        *dst++ = b;
-        *dst++ = 255;
+          *dst++ = r;
+          *dst++ = g;
+          *dst++ = b;
+          *dst++ = 255;
+        }
+        src += srcStride - (dstWriteRect.width * 4);
+        dst += (aWidth * 4) - (dstWriteRect.width * 4);
       }
-      src += srcStride - (dstWriteRect.width * 4);
-      dst += (aWidth * 4) - (dstWriteRect.width * 4);
-    }
-  } else
-  for (int32_t j = 0; j < dstWriteRect.height; ++j) {
-    for (int32_t i = 0; i < dstWriteRect.width; ++i) {
-      // XXX Is there some useful swizzle MMX we can use here?
+    } else {
+      for (int32_t j = 0; j < dstWriteRect.height; ++j) {
+        for (int32_t i = 0; i < dstWriteRect.width; ++i) {
+          // XXX Is there some useful swizzle MMX we can use here?
 #if MOZ_LITTLE_ENDIAN
-      uint8_t b = *src++;
-      uint8_t g = *src++;
-      uint8_t r = *src++;
-      uint8_t a = *src++;
+          uint8_t b = *src++;
+          uint8_t g = *src++;
+          uint8_t r = *src++;
+          uint8_t a = *src++;
 #else
-      uint8_t a = *src++;
-      uint8_t r = *src++;
-      uint8_t g = *src++;
-      uint8_t b = *src++;
+          uint8_t a = *src++;
+          uint8_t r = *src++;
+          uint8_t g = *src++;
+          uint8_t b = *src++;
 #endif
-      // Convert to non-premultiplied color
-      *dst++ = gfxUtils::sUnpremultiplyTable[a * 256 + r];
-      *dst++ = gfxUtils::sUnpremultiplyTable[a * 256 + g];
-      *dst++ = gfxUtils::sUnpremultiplyTable[a * 256 + b];
-      *dst++ = a;
+          // Convert to non-premultiplied color
+          *dst++ = gfxUtils::sUnpremultiplyTable[a * 256 + r];
+          *dst++ = gfxUtils::sUnpremultiplyTable[a * 256 + g];
+          *dst++ = gfxUtils::sUnpremultiplyTable[a * 256 + b];
+          *dst++ = a;
+        }
+        src += srcStride - (dstWriteRect.width * 4);
+        dst += (aWidth * 4) - (dstWriteRect.width * 4);
+      }
     }
-    src += srcStride - (dstWriteRect.width * 4);
-    dst += (aWidth * 4) - (dstWriteRect.width * 4);
   }
 
   if (readback) {
diff --git a/dom/canvas/ImageBitmap.cpp b/dom/canvas/ImageBitmap.cpp
index 46fb1e9a887b..5d0053c86b40 100644
--- a/dom/canvas/ImageBitmap.cpp
+++ b/dom/canvas/ImageBitmap.cpp
@@ -916,7 +916,7 @@ ImageBitmap::CreateInternal(nsIGlobalObject* aGlobal, HTMLCanvasElement& aCanvas
        aCanvasEl.GetCurrentContextType() == CanvasContextType::WebGL2) &&
       aCropRect.isSome()) {
     // The _surface_ must be a DataSourceSurface.
-    MOZ_ASSERT(surface->GetType() == SurfaceType::DATA,
+    MOZ_ASSERT(surface->IsDataSourceSurface(),
                "The snapshot SourceSurface from WebGL rendering contest is not \
                DataSourceSurface.");
     RefPtr<DataSourceSurface> dataSurface = surface->GetDataSurface();
diff --git a/dom/canvas/crashtests/1334366-1.html b/dom/canvas/crashtests/1334366-1.html
new file mode 100644
index 000000000000..0b7bc65d9d07
--- /dev/null
+++ b/dom/canvas/crashtests/1334366-1.html
@@ -0,0 +1,8 @@
+<script>
+Logger={}; Logger.JSError=function(e){};
+try { o0 = document.createElement('canvas'); } catch(e) { Logger.JSError(e); }
+try { (document.body || document.documentElement).appendChild(o0) } catch(e) { Logger.JSError(e); }
+try { o1 = o0.getContext('2d'); } catch(e) { Logger.JSError(e); }
+try { o1.translate(1152921504606847000, 0.919677262874245) } catch(e) { Logger.JSError(e); }
+try { o1.fillText("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",0.6494016751296356,-16,0.5988693960474034) } catch(e) { Logger.JSError(e); }
+</script>
diff --git a/dom/canvas/crashtests/1334647-1.html b/dom/canvas/crashtests/1334647-1.html
new file mode 100644
index 000000000000..b4510afebb7b
--- /dev/null
+++ b/dom/canvas/crashtests/1334647-1.html
@@ -0,0 +1,8 @@
+<script>
+Logger={}; Logger.JSError=function(e){};
+try { o0 = document.createElement('canvas'); } catch(e) { Logger.JSError(e); }
+try { (document.body || document.documentElement).appendChild(o0) } catch(e) { Logger.JSError(e); }
+try { o1 = o0.getContext('2d'); } catch(e) { Logger.JSError(e); }
+try { o0.width = 311853383.455201; } catch(e) { Logger.JSError(e); }
+try { o1.drawImage(o0, -0.906275445340731, 0.3679144809413502, 2, 32) } catch(e) { Logger.JSError(e); }
+</script>
diff --git a/dom/canvas/crashtests/crashtests.list b/dom/canvas/crashtests/crashtests.list
index f5a283aa927f..c85d03829e60 100644
--- a/dom/canvas/crashtests/crashtests.list
+++ b/dom/canvas/crashtests/crashtests.list
@@ -39,4 +39,6 @@ load 1286458-1.html
 load 1299062-1.html
 load 1305312-1.html
 load 1298576-1.html
+load 1334366-1.html
+load 1334647-1.html
 
diff --git a/dom/canvas/test/reftest/filters/reftest-stylo.list b/dom/canvas/test/reftest/filters/reftest-stylo.list
index 1ba50720d67a..315a400ad544 100644
--- a/dom/canvas/test/reftest/filters/reftest-stylo.list
+++ b/dom/canvas/test/reftest/filters/reftest-stylo.list
@@ -1,31 +1,31 @@
 # DO NOT EDIT! This is a auto-generated temporary list for Stylo testing
 default-preferences pref(canvas.filters.enabled,true)
 
-fails == default-color.html default-color.html
+fails asserts-if(stylo,2) == default-color.html default-color.html # bug 1324700
 # == drop-shadow.html drop-shadow.html
-fails == drop-shadow-transformed.html drop-shadow-transformed.html
-fails == global-alpha.html global-alpha.html
-fails == global-composite-operation.html global-composite-operation.html
-fails == liveness.html liveness.html
-fails == multiple-drop-shadows.html multiple-drop-shadows.html
-fails == shadow.html shadow.html
-fails == subregion-fill-paint.html subregion-fill-paint.html
-fails == subregion-stroke-paint.html subregion-stroke-paint.html
-fails == svg-bbox.html svg-bbox.html
-fails == svg-inline.html svg-inline.html
-fails == svg-liveness.html svg-liveness.html
-fails == svg-off-screen.html svg-off-screen.html
-fails == units.html units.html
-fails == units-em.html units-em.html
-fails == units-ex.html units-ex.html
-fails == units-off-screen.html units-off-screen.html
-fails == fillText-with-filter-opacity-1.html fillText-with-filter-opacity-1.html
-fails == fillText-with-filter-opacity-2.html fillText-with-filter-opacity-2.html
-fails == strokeText-with-filter-grayscale-1.html strokeText-with-filter-grayscale-1.html
-fails == strokeText-with-filter-grayscale-2.html strokeText-with-filter-grayscale-2.html
-fails == fillText-with-shadow-1.html fillText-with-shadow-1.html
-fails == fillText-with-shadow-2.html fillText-with-shadow-2.html
-fails == fillText-with-filter-grayscale-1.html fillText-with-filter-grayscale-1.html
-fails == fillText-with-filter-grayscale-2.html fillText-with-filter-grayscale-2.html
-fails == strokeText-with-shadow-1.html strokeText-with-shadow-1.html
-fails == strokeText-with-shadow-2.html strokeText-with-shadow-2.html
+fails asserts-if(stylo,2) == drop-shadow-transformed.html drop-shadow-transformed.html # bug 1324700
+fails asserts-if(stylo,2) == global-alpha.html global-alpha.html # bug 1324700
+fails asserts-if(stylo,2) == global-composite-operation.html global-composite-operation.html # bug 1324700
+fails asserts-if(stylo,1) == liveness.html liveness.html # bug 1324700
+fails asserts-if(stylo,2) == multiple-drop-shadows.html multiple-drop-shadows.html # bug 1324700
+fails asserts-if(stylo,2) == shadow.html shadow.html # bug 1324700
+fails asserts-if(stylo,2) == subregion-fill-paint.html subregion-fill-paint.html # bug 1324700
+fails asserts-if(stylo,2) == subregion-stroke-paint.html subregion-stroke-paint.html # bug 1324700
+fails asserts-if(stylo,2) == svg-bbox.html svg-bbox.html # bug 1324700
+fails asserts-if(stylo,2) == svg-inline.html svg-inline.html # bug 1324700
+fails asserts-if(stylo,2) == svg-liveness.html svg-liveness.html # bug 1324700
+fails asserts-if(stylo,2) == svg-off-screen.html svg-off-screen.html # bug 1324700
+fails asserts-if(stylo,2) == units.html units.html # bug 1324700
+fails asserts-if(stylo,1) == units-em.html units-em.html # bug 1324700
+fails asserts-if(stylo,1) == units-ex.html units-ex.html # bug 1324700
+fails asserts-if(stylo,2) == units-off-screen.html units-off-screen.html # bug 1324700
+fails asserts-if(stylo,2) == fillText-with-filter-opacity-1.html fillText-with-filter-opacity-1.html # bug 1324700
+fails asserts-if(stylo,2) == fillText-with-filter-opacity-2.html fillText-with-filter-opacity-2.html # bug 1324700
+fails asserts-if(stylo,2) == strokeText-with-filter-grayscale-1.html strokeText-with-filter-grayscale-1.html # bug 1324700
+fails asserts-if(stylo,2) == strokeText-with-filter-grayscale-2.html strokeText-with-filter-grayscale-2.html # bug 1324700
+fails asserts-if(stylo,1) == fillText-with-shadow-1.html fillText-with-shadow-1.html # bug 1324700
+fails asserts-if(stylo,1) == fillText-with-shadow-2.html fillText-with-shadow-2.html # bug 1324700
+fails asserts-if(stylo,2) == fillText-with-filter-grayscale-1.html fillText-with-filter-grayscale-1.html # bug 1324700
+fails asserts-if(stylo,2) == fillText-with-filter-grayscale-2.html fillText-with-filter-grayscale-2.html # bug 1324700
+fails asserts-if(stylo,1) == strokeText-with-shadow-1.html strokeText-with-shadow-1.html # bug 1324700
+fails asserts-if(stylo,1) == strokeText-with-shadow-2.html strokeText-with-shadow-2.html # bug 1324700
diff --git a/dom/canvas/test/reftest/reftest-stylo.list b/dom/canvas/test/reftest/reftest-stylo.list
index 75ca4d548d6b..04f2da781a91 100644
--- a/dom/canvas/test/reftest/reftest-stylo.list
+++ b/dom/canvas/test/reftest/reftest-stylo.list
@@ -155,16 +155,16 @@ skip-if(!winWidget) pref(webgl.disable-angle,true) == webgl-color-test.html?nati
 == clip-multiple-move-2.html clip-multiple-move-2.html
 
 # Bug 815648
-fails == stroketext-shadow.html stroketext-shadow.html
+fails asserts-if(stylo,1) == stroketext-shadow.html stroketext-shadow.html # bug 1324700
 
 # focus rings
-pref(canvas.focusring.enabled,true) skip-if(cocoaWidget) skip-if(winWidget) needs-focus == drawFocusIfNeeded.html drawFocusIfNeeded.html
-pref(canvas.customfocusring.enabled,true) skip-if(Android||cocoaWidget||winWidget) fuzzy-if(gtkWidget,64,410) needs-focus == drawCustomFocusRing.html drawCustomFocusRing.html
+pref(canvas.focusring.enabled,true) skip-if(cocoaWidget) skip-if(winWidget) asserts-if(stylo,6) needs-focus == drawFocusIfNeeded.html drawFocusIfNeeded.html # bug 1324671
+pref(canvas.customfocusring.enabled,true) skip-if(Android||cocoaWidget||winWidget) fuzzy-if(gtkWidget,64,410) asserts-if(stylo,6) needs-focus == drawCustomFocusRing.html drawCustomFocusRing.html # bug 1324671
 
 # Check that captureStream() displays in a local video element
 == capturestream.html capturestream.html
 
-fails == 1177726-text-stroke-bounds.html 1177726-text-stroke-bounds.html
+fails asserts-if(stylo,1) == 1177726-text-stroke-bounds.html 1177726-text-stroke-bounds.html # bug 1324700
 
 # Canvas Filter Reftests
 include filters/reftest-stylo.list
diff --git a/dom/filesystem/GetFilesHelper.cpp b/dom/filesystem/GetFilesHelper.cpp
index fe92602d2431..e6a180228ce8 100644
--- a/dom/filesystem/GetFilesHelper.cpp
+++ b/dom/filesystem/GetFilesHelper.cpp
@@ -25,12 +25,13 @@ public:
                            Sequence<RefPtr<File>>& aFiles,
                            already_AddRefed<nsIGlobalObject> aGlobal)
   {
+    nsCOMPtr<nsIGlobalObject> global(aGlobal);
     if (NS_IsMainThread()) {
       return;
     }
 
     RefPtr<ReleaseRunnable> runnable =
-      new ReleaseRunnable(aPromises, aCallbacks, aFiles, Move(aGlobal));
+      new ReleaseRunnable(aPromises, aCallbacks, aFiles, global.forget());
     NS_DispatchToMainThread(runnable);
   }
 
diff --git a/dom/html/crashtests/crashtests.list b/dom/html/crashtests/crashtests.list
index 3661ba54db8e..6ef539a648bd 100644
--- a/dom/html/crashtests/crashtests.list
+++ b/dom/html/crashtests/crashtests.list
@@ -56,7 +56,7 @@ load 741250.xhtml
 load 795221-1.html
 asserts-if(stylo,1) load 795221-2.html # bug 1324702
 load 795221-3.html
-asserts-if(stylo,2) load 795221-4.html # bug 1324669
+load 795221-4.html
 load 795221-5.xml
 load 811226.html
 load 819745.html
diff --git a/dom/ipc/TabParent.cpp b/dom/ipc/TabParent.cpp
index 085940d89f6e..5c2badde9349 100644
--- a/dom/ipc/TabParent.cpp
+++ b/dom/ipc/TabParent.cpp
@@ -980,7 +980,7 @@ TabParent::GetTopLevelDocAccessible() const
   const ManagedContainer<PDocAccessibleParent>& docs = ManagedPDocAccessibleParent();
   for (auto iter = docs.ConstIter(); !iter.Done(); iter.Next()) {
     auto doc = static_cast<a11y::DocAccessibleParent*>(iter.Get()->GetKey());
-    if (!doc->ParentDoc()) {
+    if (doc->IsTopLevel()) {
       return doc;
     }
   }
diff --git a/dom/media/tests/mochitest/mochitest.ini b/dom/media/tests/mochitest/mochitest.ini
index f93adbb6777c..2540913d9371 100644
--- a/dom/media/tests/mochitest/mochitest.ini
+++ b/dom/media/tests/mochitest/mochitest.ini
@@ -168,7 +168,7 @@ skip-if = (android_version == '18') # android(Bug 1189784, timeouts on 4.3 emula
 [test_peerConnection_offerRequiresReceiveVideoAudio.html]
 skip-if = (android_version == '18') # android(Bug 1189784, timeouts on 4.3 emulator)
 [test_peerConnection_promiseSendOnly.html]
-skip-if = (android_version == '18' && debug) # android(Bug 1189784, timeouts on 4.3 emulator)
+skip-if = (android_version == '18') # android(Bug 1189784, 1318809 timeouts on 4.3 emulator)
 [test_peerConnection_renderAfterRenegotiation.html]
 skip-if = (android_version == '18') # android(Bug 1189784, 1326005 timeouts on 4.3 emulator)
 [test_peerConnection_restartIce.html]
diff --git a/dom/smil/crashtests/crashtests.list b/dom/smil/crashtests/crashtests.list
index af2c4f6affe5..6c2b2656affe 100644
--- a/dom/smil/crashtests/crashtests.list
+++ b/dom/smil/crashtests/crashtests.list
@@ -23,13 +23,13 @@ load 572938-3.svg
 load 572938-4.svg
 load 588287-1.svg
 load 588287-2.svg
-asserts-if(stylo,2) load 590425-1.html # bug 1324669
-asserts-if(stylo,1-27) load 592477-1.xhtml # bug 1324669
+load 590425-1.html
+load 592477-1.xhtml
 load 594653-1.svg
 load 596796-1.svg
 load 605345-1.svg
 load 606101-1.svg
-asserts-if(stylo,2) load 608295-1.html # bug 1324689
+asserts-if(stylo,1) load 608295-1.html # bug 1324689
 load 608549-1.svg
 load 611927-1.svg
 load 615002-1.svg
diff --git a/dom/smil/nsSMILAnimationController.cpp b/dom/smil/nsSMILAnimationController.cpp
index fd32475ecf20..e476dcf8b068 100644
--- a/dom/smil/nsSMILAnimationController.cpp
+++ b/dom/smil/nsSMILAnimationController.cpp
@@ -323,7 +323,7 @@ nsSMILAnimationController::DoSample(bool aSkipUnchangedContainers)
   mResampleNeeded = false;
 
   if (mDocument->IsStyledByServo()) {
-    NS_ERROR("stylo: SMIL animations not supported yet");
+    NS_WARNING("stylo: SMIL animations not supported yet");
     return;
   }
 
diff --git a/dom/svg/crashtests/crashtests.list b/dom/svg/crashtests/crashtests.list
index 751283389260..1a0b2c4d33ab 100644
--- a/dom/svg/crashtests/crashtests.list
+++ b/dom/svg/crashtests/crashtests.list
@@ -4,7 +4,7 @@ load 336994-1.html
 load 344888-1.svg
 load 345445-1.svg
 load 360836-1.svg
-asserts-if(stylo,2) load 367357-1.xhtml # bug 1324669
+load 367357-1.xhtml
 load 369051-1.svg
 load 369249-1.svg
 load 369291-1.svg
@@ -75,13 +75,13 @@ load 898915-1.svg
 load 1035248-1.svg
 load 1035248-2.svg
 load 1244898-1.xhtml
-asserts-if(stylo,2) load 1250725.html # bug 1324669
+load 1250725.html
 load 1267272-1.svg
 load 1282985-1.svg
 # Disabled for now due to it taking a very long time to run - bug 1259356
 #load long-clipPath-reference-chain.svg
 load zero-size-image.svg
-asserts-if(stylo,2) load 1322286.html # bug 1324669
+load 1322286.html
 load 1329849-1.svg
 load 1329849-2.svg
 load 1329849-3.svg
diff --git a/dom/workers/ServiceWorkerClients.cpp b/dom/workers/ServiceWorkerClients.cpp
index 07fe4910d189..7000f7996f16 100644
--- a/dom/workers/ServiceWorkerClients.cpp
+++ b/dom/workers/ServiceWorkerClients.cpp
@@ -485,12 +485,22 @@ NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(WebProgressListener)
 NS_INTERFACE_MAP_END
 
 class OpenWindowRunnable final : public Runnable
+                               , public nsIObserver
+                               , public nsSupportsWeakReference
 {
   RefPtr<PromiseWorkerProxy> mPromiseProxy;
   nsString mUrl;
   nsString mScope;
 
 public:
+  NS_DECL_ISUPPORTS_INHERITED
+  // Note: |OpenWindowRunnable| cannot be cycle collected because it inherits
+  // thread safe reference counting from |mozilla::Runnable|. On Fennec, we
+  // might use |ServiceWorkerPrivate::StoreISupports| to keep this object alive
+  // while waiting for an event from the observer service. As such, to avoid
+  // creating a cycle that will leak, |OpenWindowRunnable| must not hold a strong
+  // reference to |ServiceWorkerPrivate|.
+
   OpenWindowRunnable(PromiseWorkerProxy* aPromiseProxy,
                      const nsAString& aUrl,
                      const nsAString& aScope)
@@ -503,6 +513,30 @@ public:
     aPromiseProxy->GetWorkerPrivate()->AssertIsOnWorkerThread();
   }
 
+  NS_IMETHOD
+  Observe(nsISupports* aSubject, const char* aTopic, const char16_t* /* aData */) override
+  {
+    AssertIsOnMainThread();
+
+    nsCString topic(aTopic);
+    if (!topic.Equals(NS_LITERAL_CSTRING("BrowserChrome:Ready"))) {
+      MOZ_ASSERT(false, "Unexpected topic.");
+      return NS_ERROR_FAILURE;
+    }
+
+    nsCOMPtr<nsIObserverService> os = services::GetObserverService();
+    NS_ENSURE_STATE(os);
+    os->RemoveObserver(this, "BrowserChrome:Ready");
+
+    RefPtr<ServiceWorkerPrivate> swp = GetServiceWorkerPrivate();
+    NS_ENSURE_STATE(swp);
+
+    MOZ_ALWAYS_SUCCEEDS(NS_DispatchToMainThread(this));
+    swp->RemoveISupports(static_cast<nsIObserver*>(this));
+
+    return NS_OK;
+  }
+
   NS_IMETHOD
   Run() override
   {
@@ -546,28 +580,11 @@ public:
         return NS_ERROR_FAILURE;
       }
 
-      RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();
-      if (!swm) {
-        // browser shutdown
-        return NS_ERROR_FAILURE;
-      }
-
-      nsCOMPtr<nsIPrincipal> principal = workerPrivate->GetPrincipal();
-      MOZ_ASSERT(principal);
-      RefPtr<ServiceWorkerRegistrationInfo> registration =
-        swm->GetRegistration(principal, NS_ConvertUTF16toUTF8(mScope));
-      if (NS_WARN_IF(!registration)) {
-        return NS_ERROR_FAILURE;
-      }
-      RefPtr<ServiceWorkerInfo> serviceWorkerInfo =
-        registration->GetServiceWorkerInfoById(workerPrivate->ServiceWorkerID());
-      if (NS_WARN_IF(!serviceWorkerInfo)) {
-        return NS_ERROR_FAILURE;
-      }
+      RefPtr<ServiceWorkerPrivate> swp = GetServiceWorkerPrivate();
+      NS_ENSURE_STATE(swp);
 
       nsCOMPtr<nsIWebProgressListener> listener =
-        new WebProgressListener(mPromiseProxy, serviceWorkerInfo->WorkerPrivate(),
-                                window, baseURI);
+        new WebProgressListener(mPromiseProxy, swp, window, baseURI);
 
       rv = webProgress->AddProgressListener(listener,
                                             nsIWebProgress::NOTIFY_STATE_DOCUMENT);
@@ -579,36 +596,17 @@ public:
       // We couldn't get a browser window, so Fennec must not be running.
       // Send an Intent to launch Fennec and wait for "BrowserChrome:Ready"
       // to try opening a window again.
+      RefPtr<ServiceWorkerPrivate> swp = GetServiceWorkerPrivate();
+      NS_ENSURE_STATE(swp);
+
       nsCOMPtr<nsIObserverService> os = services::GetObserverService();
       NS_ENSURE_STATE(os);
 
-      WorkerPrivate* workerPrivate = mPromiseProxy->GetWorkerPrivate();
-      MOZ_ASSERT(workerPrivate);
+      rv = os->AddObserver(this, "BrowserChrome:Ready", /* weakRef */ true);
+      NS_ENSURE_SUCCESS(rv, rv);
 
-      RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();
-      if (!swm) {
-        // browser shutdown
-        return NS_ERROR_FAILURE;
-      }
+      swp->StoreISupports(static_cast<nsIObserver*>(this));
 
-      nsCOMPtr<nsIPrincipal> principal = workerPrivate->GetPrincipal();
-      MOZ_ASSERT(principal);
-
-      RefPtr<ServiceWorkerRegistrationInfo> registration =
-        swm->GetRegistration(principal, NS_ConvertUTF16toUTF8(mScope));
-      if (NS_WARN_IF(!registration)) {
-        return NS_ERROR_FAILURE;
-      }
-
-      RefPtr<ServiceWorkerInfo> serviceWorkerInfo =
-        registration->GetServiceWorkerInfoById(workerPrivate->ServiceWorkerID());
-      if (NS_WARN_IF(!serviceWorkerInfo)) {
-        return NS_ERROR_FAILURE;
-      }
-
-      os->AddObserver(static_cast<nsIObserver*>(serviceWorkerInfo->WorkerPrivate()),
-                      "BrowserChrome:Ready", true);
-      serviceWorkerInfo->WorkerPrivate()->AddPendingWindow(this);
       return NS_OK;
     }
 #endif
@@ -622,6 +620,41 @@ public:
   }
 
 private:
+  ~OpenWindowRunnable()
+  { }
+
+  ServiceWorkerPrivate*
+  GetServiceWorkerPrivate() const
+  {
+    AssertIsOnMainThread();
+
+    RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();
+    if (!swm) {
+      // browser shutdown
+      return nullptr;
+    }
+
+    WorkerPrivate* workerPrivate = mPromiseProxy->GetWorkerPrivate();
+    MOZ_ASSERT(workerPrivate);
+
+    nsCOMPtr<nsIPrincipal> principal = workerPrivate->GetPrincipal();
+    MOZ_DIAGNOSTIC_ASSERT(principal);
+
+    RefPtr<ServiceWorkerRegistrationInfo> registration =
+      swm->GetRegistration(principal, NS_ConvertUTF16toUTF8(mScope));
+    if (NS_WARN_IF(!registration)) {
+      return nullptr;
+    }
+
+    RefPtr<ServiceWorkerInfo> serviceWorkerInfo =
+      registration->GetServiceWorkerInfoById(workerPrivate->ServiceWorkerID());
+    if (NS_WARN_IF(!serviceWorkerInfo)) {
+      return nullptr;
+    }
+
+    return serviceWorkerInfo->WorkerPrivate();
+  }
+
   nsresult
   OpenWindow(nsPIDOMWindowOuter** aWindow)
   {
@@ -730,6 +763,16 @@ private:
   }
 };
 
+NS_IMPL_ADDREF_INHERITED(OpenWindowRunnable, Runnable)                                    \
+NS_IMPL_RELEASE_INHERITED(OpenWindowRunnable, Runnable)
+
+NS_INTERFACE_MAP_BEGIN(OpenWindowRunnable)
+NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
+NS_INTERFACE_MAP_ENTRY(nsIObserver)
+NS_INTERFACE_MAP_ENTRY(nsIRunnable)
+NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIObserver)
+NS_INTERFACE_MAP_END
+
 } // namespace
 
 already_AddRefed<Promise>
diff --git a/dom/workers/ServiceWorkerManager.cpp b/dom/workers/ServiceWorkerManager.cpp
index cedeafefc201..2a89faff91b1 100644
--- a/dom/workers/ServiceWorkerManager.cpp
+++ b/dom/workers/ServiceWorkerManager.cpp
@@ -3200,7 +3200,7 @@ ServiceWorkerManager::GetRegistration(const nsACString& aScopeKey,
   return reg.forget();
 }
 
-ServiceWorkerRegistrationInfo*
+already_AddRefed<ServiceWorkerRegistrationInfo>
 ServiceWorkerManager::CreateNewRegistration(const nsCString& aScope,
                                             nsIPrincipal* aPrincipal,
                                             nsLoadFlags aLoadFlags)
@@ -3216,12 +3216,12 @@ ServiceWorkerManager::CreateNewRegistration(const nsCString& aScope,
   MOZ_ASSERT(!tmp);
 #endif
 
-  ServiceWorkerRegistrationInfo* registration =
+  RefPtr<ServiceWorkerRegistrationInfo> registration =
     new ServiceWorkerRegistrationInfo(aScope, aPrincipal, aLoadFlags);
   // From now on ownership of registration is with
   // mServiceWorkerRegistrationInfos.
   AddScopeAndRegistration(aScope, registration);
-  return registration;
+  return registration.forget();
 }
 
 void
diff --git a/dom/workers/ServiceWorkerManager.h b/dom/workers/ServiceWorkerManager.h
index 610cd0d88e27..06eedec7e576 100644
--- a/dom/workers/ServiceWorkerManager.h
+++ b/dom/workers/ServiceWorkerManager.h
@@ -187,7 +187,7 @@ public:
   already_AddRefed<ServiceWorkerRegistrationInfo>
   GetRegistration(nsIPrincipal* aPrincipal, const nsACString& aScope) const;
 
-  ServiceWorkerRegistrationInfo*
+  already_AddRefed<ServiceWorkerRegistrationInfo>
   CreateNewRegistration(const nsCString& aScope,
                         nsIPrincipal* aPrincipal,
                         nsLoadFlags aLoadFlags);
diff --git a/dom/workers/ServiceWorkerPrivate.cpp b/dom/workers/ServiceWorkerPrivate.cpp
index 0a71a224dce9..9e028efa8e71 100644
--- a/dom/workers/ServiceWorkerPrivate.cpp
+++ b/dom/workers/ServiceWorkerPrivate.cpp
@@ -37,14 +37,12 @@ using namespace mozilla::dom;
 
 BEGIN_WORKERS_NAMESPACE
 
-NS_IMPL_CYCLE_COLLECTING_ADDREF(ServiceWorkerPrivate)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(ServiceWorkerPrivate)
+NS_IMPL_CYCLE_COLLECTING_NATIVE_ADDREF(ServiceWorkerPrivate)
+NS_IMPL_CYCLE_COLLECTING_NATIVE_RELEASE(ServiceWorkerPrivate)
 NS_IMPL_CYCLE_COLLECTION(ServiceWorkerPrivate, mSupportsArray)
 
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ServiceWorkerPrivate)
-  NS_INTERFACE_MAP_ENTRY(nsISupports)
-  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIObserver)
-NS_INTERFACE_MAP_END
+NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(ServiceWorkerPrivate, AddRef)
+NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(ServiceWorkerPrivate, Release)
 
 // Tracks the "dom.disable_open_click_delay" preference.  Modified on main
 // thread, read on worker threads.
@@ -1866,7 +1864,7 @@ ServiceWorkerPrivate::TerminateWorker()
     if (Preferences::GetBool("dom.serviceWorkers.testing.enabled")) {
       nsCOMPtr<nsIObserverService> os = services::GetObserverService();
       if (os) {
-        os->NotifyObservers(this, "service-worker-shutdown", nullptr);
+        os->NotifyObservers(nullptr, "service-worker-shutdown", nullptr);
       }
     }
 
@@ -2096,38 +2094,6 @@ ServiceWorkerPrivate::CreateEventKeepAliveToken()
   return ref.forget();
 }
 
-void
-ServiceWorkerPrivate::AddPendingWindow(Runnable* aPendingWindow)
-{
-  AssertIsOnMainThread();
-  pendingWindows.AppendElement(aPendingWindow);
-}
-
-nsresult
-ServiceWorkerPrivate::Observe(nsISupports* aSubject, const char* aTopic, const char16_t* aData)
-{
-  AssertIsOnMainThread();
-
-  nsCString topic(aTopic);
-  if (!topic.Equals(NS_LITERAL_CSTRING("BrowserChrome:Ready"))) {
-    MOZ_ASSERT(false, "Unexpected topic.");
-    return NS_ERROR_FAILURE;
-  }
-
-  nsCOMPtr<nsIObserverService> os = services::GetObserverService();
-  NS_ENSURE_STATE(os);
-  os->RemoveObserver(static_cast<nsIObserver*>(this), "BrowserChrome:Ready");
-
-  size_t len = pendingWindows.Length();
-  for (int i = len-1; i >= 0; i--) {
-    RefPtr<Runnable> runnable = pendingWindows[i];
-    MOZ_ALWAYS_SUCCEEDS(NS_DispatchToMainThread(runnable));
-    pendingWindows.RemoveElementAt(i);
-  }
-
-  return NS_OK;
-}
-
 void
 ServiceWorkerPrivate::SetHandlesFetch(bool aValue)
 {
diff --git a/dom/workers/ServiceWorkerPrivate.h b/dom/workers/ServiceWorkerPrivate.h
index 9b59082bdbdf..ccc50495863e 100644
--- a/dom/workers/ServiceWorkerPrivate.h
+++ b/dom/workers/ServiceWorkerPrivate.h
@@ -62,15 +62,22 @@ public:
 // with an appropriate reason before any runnable is dispatched to the worker.
 // If the event is extendable then the runnable should inherit
 // ExtendableEventWorkerRunnable.
-class ServiceWorkerPrivate final : public nsIObserver
+class ServiceWorkerPrivate final
 {
   friend class KeepAliveToken;
 
 public:
-  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_CLASS(ServiceWorkerPrivate)
-  NS_DECL_NSIOBSERVER
+  NS_IMETHOD_(MozExternalRefCountType) AddRef();
+  NS_IMETHOD_(MozExternalRefCountType) Release();
+  NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(ServiceWorkerPrivate)
 
+  typedef mozilla::FalseType HasThreadSafeRefCnt;
+
+protected:
+  nsCycleCollectingAutoRefCnt mRefCnt;
+  NS_DECL_OWNINGTHREAD
+
+public:
   explicit ServiceWorkerPrivate(ServiceWorkerInfo* aInfo);
 
   nsresult
@@ -150,9 +157,6 @@ public:
   bool
   IsIdle() const;
 
-  void
-  AddPendingWindow(Runnable* aPendingWindow);
-
   void
   SetHandlesFetch(bool aValue);
 
@@ -228,8 +232,6 @@ private:
   // Array of function event worker runnables that are pending due to
   // the worker activating.  Main thread only.
   nsTArray<RefPtr<WorkerRunnable>> mPendingFunctionalEvents;
-
-  nsTArray<Runnable*> pendingWindows;
 };
 
 } // namespace workers
diff --git a/dom/xhr/XMLHttpRequestMainThread.cpp b/dom/xhr/XMLHttpRequestMainThread.cpp
index 01bb2b33bd9f..26b7cc0b36c5 100644
--- a/dom/xhr/XMLHttpRequestMainThread.cpp
+++ b/dom/xhr/XMLHttpRequestMainThread.cpp
@@ -741,6 +741,15 @@ XMLHttpRequestMainThread::SetResponseType(XMLHttpRequestResponseType aResponseTy
     return;
   }
 
+  // We want to get rid of this moz-only types. Bug 1335365.
+  if (aResponseType == XMLHttpRequestResponseType::Moz_blob) {
+    Telemetry::Accumulate(Telemetry::MOZ_BLOB_IN_XHR, 1);
+  } else if (aResponseType == XMLHttpRequestResponseType::Moz_chunked_text) {
+    Telemetry::Accumulate(Telemetry::MOZ_CHUNKED_TEXT_IN_XHR, 1);
+  } else if (aResponseType == XMLHttpRequestResponseType::Moz_chunked_arraybuffer) {
+    Telemetry::Accumulate(Telemetry::MOZ_CHUNKED_ARRAYBUFFER_IN_XHR, 1);
+  }
+
   // Set the responseType attribute's value to the given value.
   mResponseType = aResponseType;
 }
diff --git a/editor/libeditor/crashtests/crashtests.list b/editor/libeditor/crashtests/crashtests.list
index fc32835d142f..36a92b5ddfe6 100644
--- a/editor/libeditor/crashtests/crashtests.list
+++ b/editor/libeditor/crashtests/crashtests.list
@@ -1,5 +1,5 @@
 load 336081-1.xhtml
-asserts-if(stylo,2-3) load 336104.html # bug 1324669
+load 336104.html
 load 382527-1.html
 load 382778-1.html
 load 402172-1.html
diff --git a/editor/reftests/reftest-stylo.list b/editor/reftests/reftest-stylo.list
index 4f2341b418d6..85763fb702c5 100644
--- a/editor/reftests/reftest-stylo.list
+++ b/editor/reftests/reftest-stylo.list
@@ -102,7 +102,7 @@ fails == dynamic-overflow-change.html dynamic-overflow-change.html
 fails == 694880-1.html 694880-1.html
 fails == 694880-2.html 694880-2.html
 fails == 694880-3.html 694880-3.html
-fails == 388980-1.html 388980-1.html
+fails asserts-if(stylo,1) == 388980-1.html 388980-1.html # bug 1324683
 fails needs-focus == spellcheck-superscript-1.html spellcheck-superscript-1.html
 fails == spellcheck-superscript-2.html spellcheck-superscript-2.html
 == 824080-1.html 824080-1.html
@@ -134,5 +134,5 @@ fails needs-focus pref(layout.accessiblecaret.enabled,false) pref(layout.accessi
 == spellcheck-contenteditable-property-dynamic-override-inherit.html spellcheck-contenteditable-property-dynamic-override-inherit.html
 # == 911201.html 911201.html
 fails needs-focus == 969773.html 969773.html
-fails == 997805.html 997805.html
-fails == 1088158.html 1088158.html
+fails asserts-if(stylo,2) == 997805.html 997805.html # bug 1324671
+fails asserts-if(stylo,1) == 1088158.html 1088158.html # bug 1324671
diff --git a/gfx/2d/2D.h b/gfx/2d/2D.h
index 3c8d7e959fe0..f03d51ae5ba3 100644
--- a/gfx/2d/2D.h
+++ b/gfx/2d/2D.h
@@ -352,6 +352,16 @@ public:
    */
   virtual bool IsValid() const { return true; }
 
+  /**
+   * This function will return true if the surface type matches that of a
+   * DataSourceSurface and if GetDataSurface will return the same object.
+   */
+  bool IsDataSourceSurface() const {
+    SurfaceType type = GetType();
+    return type == SurfaceType::DATA ||
+           type == SurfaceType::DATA_SHARED;
+  }
+
   /**
    * This function will get a DataSourceSurface for this surface, a
    * DataSourceSurface's data can be accessed directly.
@@ -495,6 +505,24 @@ public:
    */
   virtual already_AddRefed<DataSourceSurface> GetDataSurface() override;
 
+  /**
+   * Add the size of the underlying data buffer to the aggregate.
+   */
+  virtual void AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
+                                      size_t& aHeapSizeOut,
+                                      size_t& aNonHeapSizeOut) const
+  {
+  }
+
+  /**
+   * Returns whether or not the data was allocated on the heap. This should
+   * be used to determine if the memory needs to be cleared to 0.
+   */
+  virtual bool OnHeap() const
+  {
+    return true;
+  }
+
 protected:
   bool mIsMapped;
 };
diff --git a/gfx/2d/DataSourceSurface.cpp b/gfx/2d/DataSourceSurface.cpp
index 75d84350642c..42f075e0d9b6 100644
--- a/gfx/2d/DataSourceSurface.cpp
+++ b/gfx/2d/DataSourceSurface.cpp
@@ -13,7 +13,7 @@ already_AddRefed<DataSourceSurface>
 DataSourceSurface::GetDataSurface()
 {
   RefPtr<DataSourceSurface> surface =
-    (GetType() == SurfaceType::DATA) ? this : new DataSourceSurfaceWrapper(this);
+    IsDataSourceSurface() ? this : new DataSourceSurfaceWrapper(this);
   return surface.forget();
 }
 
diff --git a/gfx/2d/HelpersD2D.h b/gfx/2d/HelpersD2D.h
index d31ba341d846..82f12abfcbd7 100644
--- a/gfx/2d/HelpersD2D.h
+++ b/gfx/2d/HelpersD2D.h
@@ -617,6 +617,11 @@ CreatePartialBitmapForSurface(DataSourceSurface *aSurface, const Matrix &aDestin
     uploadRect.height = rect.height;
   }
 
+  if (uploadRect.IsEmpty()) {
+    // Nothing to be drawn.
+    return nullptr;
+  }
+
   if (uploadRect.width <= aRT->GetMaximumBitmapSize() &&
       uploadRect.height <= aRT->GetMaximumBitmapSize()) {
     {
diff --git a/gfx/2d/Logging.h b/gfx/2d/Logging.h
index 0d9886cff5cf..7ac4ae7f9934 100644
--- a/gfx/2d/Logging.h
+++ b/gfx/2d/Logging.h
@@ -465,6 +465,9 @@ public:
         case SurfaceType::TILED:
           mMessage << "SurfaceType::TILED";
           break;
+        case SurfaceType::DATA_SHARED:
+          mMessage << "SurfaceType::DATA_SHARED";
+          break;
         default:
           mMessage << "Invalid SurfaceType (" << (int)aType << ")";
           break;
diff --git a/gfx/2d/Types.h b/gfx/2d/Types.h
index 72cba5f2ccba..915b038f0668 100644
--- a/gfx/2d/Types.h
+++ b/gfx/2d/Types.h
@@ -29,7 +29,8 @@ enum class SurfaceType : int8_t {
   DUAL_DT, /* Snapshot of a dual drawtarget */
   D2D1_1_IMAGE, /* A D2D 1.1 ID2D1Image SourceSurface */
   RECORDING, /* Surface used for recording */
-  TILED /* Surface from a tiled DrawTarget */
+  TILED, /* Surface from a tiled DrawTarget */
+  DATA_SHARED, /* Data surface using shared memory */
 };
 
 enum class SurfaceFormat : int8_t {
diff --git a/gfx/graphite2/ChangeLog b/gfx/graphite2/ChangeLog
old mode 100644
new mode 100755
index 2d5a0c11339a..b46562047a06
--- a/gfx/graphite2/ChangeLog
+++ b/gfx/graphite2/ChangeLog
@@ -1,3 +1,30 @@
+1.3.9
+    . Add Collision COLL_ISSPACE to allow for visible spaces in collision avoidance
+    . Add segment and pass direction information to tracing output
+    . Bug fix rule length testing in 32-bit
+    . Increase slanted margin distances for collision avoidance
+    . Change kerning algorithm to simple outline expansion. Seems to make no visible difference.
+    . Add trace2svg to test tools
+
+1.3.8
+    . Various bug fixes arising from fuzzing
+    . Fix regression that stopped piglatin from working
+    . Make collision avoidance kerning give more regular results
+    . Minor modification to clustering algorithm to handle variable width chars
+
+1.3.7
+    . Bug fixes
+    . Start to deprecate SegCache. This will be going away in a later release.
+
+1.3.6
+    . Bug fixes
+
+1.3.5
+    . Bug fixes
+        . Security bug fix
+        . Fix ARM misalignment problem
+        . Track latest cmake
+
 1.3.4
     . Transition from Mercurial to Git
     . Bug fixes
diff --git a/gfx/graphite2/README.mozilla b/gfx/graphite2/README.mozilla
index 255e760bd2c9..24c8861ee782 100644
--- a/gfx/graphite2/README.mozilla
+++ b/gfx/graphite2/README.mozilla
@@ -1,6 +1,3 @@
-This directory contains the Graphite2 library release 1.3.8 from
-https://github.com/silnrsi/graphite/releases/download/1.3.8/graphite2-minimal-1.3.8.tgz
+This directory contains the Graphite2 library release 1.3.9 from
+https://github.com/silnrsi/graphite/releases/download/1.3.9/graphite2-minimal-1.3.9.tgz
 See gfx/graphite2/moz-gr-update.sh for update procedure.
-
-Cherry-picked post-1.3.8 commit 56157cf9845d13452068c297205f96b946126cc2 to fix
-https://bugzilla.mozilla.org/show_bug.cgi?id=1261135.
diff --git a/gfx/graphite2/include/graphite2/Font.h b/gfx/graphite2/include/graphite2/Font.h
index 1f2ca4eaff72..b0de8e82b7cd 100644
--- a/gfx/graphite2/include/graphite2/Font.h
+++ b/gfx/graphite2/include/graphite2/Font.h
@@ -30,7 +30,7 @@
 
 #define GR2_VERSION_MAJOR   1
 #define GR2_VERSION_MINOR   3
-#define GR2_VERSION_BUGFIX  8
+#define GR2_VERSION_BUGFIX  9
 
 #ifdef __cplusplus
 extern "C"
diff --git a/gfx/graphite2/include/graphite2/XmlLog.h b/gfx/graphite2/include/graphite2/XmlLog.h
deleted file mode 100644
index 55413275690c..000000000000
--- a/gfx/graphite2/include/graphite2/XmlLog.h
+++ /dev/null
@@ -1,55 +0,0 @@
-/*  GRAPHITE2 LICENSING
-
-    Copyright 2010, SIL International
-    All rights reserved.
-
-    This library is free software; you can redistribute it and/or modify
-    it under the terms of the GNU Lesser General Public License as published
-    by the Free Software Foundation; either version 2.1 of License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Lesser General Public License for more details.
-
-    You should also have received a copy of the GNU Lesser General Public
-    License along with this library in the file named "LICENSE".
-    If not, write to the Free Software Foundation, 51 Franklin Street,
-    Suite 500, Boston, MA 02110-1335, USA or visit their web page on the
-    internet at http://www.fsf.org/licenses/lgpl.html.
-
-    Alternatively, the contents of this file may be used under the terms
-    of the Mozilla Public License (http://mozilla.org/MPL) or the GNU
-    General Public License, as published by the Free Software Foundation,
-    either version 2 of the License or (at your option) any later version.
-*/
-#pragma once
-
-#include <graphite2/Types.h>
-#include <stdio.h>
-
-typedef enum {
-    GRLOG_NONE = 0x0,
-    GRLOG_FACE = 0x01,
-    GRLOG_SEGMENT = 0x02,
-    GRLOG_PASS = 0x04,
-    GRLOG_CACHE = 0x08,
-    
-    GRLOG_OPCODE = 0x80,
-    GRLOG_ALL = 0xFF
-} GrLogMask;
-
-// If startGraphiteLogging returns true, logging is enabled and the FILE handle
-// will be closed by graphite when stopGraphiteLogging is called.
-#ifdef __cplusplus
-extern "C"
-{
-#endif
-
-GR2_API bool graphite_start_logging(FILE * logFile, GrLogMask mask);		//may not do anthing if disabled in the implementation of the engine.
-GR2_API void graphite_stop_logging();
-
-#ifdef __cplusplus
-}
-#endif
diff --git a/gfx/graphite2/src/Bidi.cpp b/gfx/graphite2/src/Bidi.cpp
deleted file mode 100644
index 48ec2ebfcd5a..000000000000
--- a/gfx/graphite2/src/Bidi.cpp
+++ /dev/null
@@ -1,826 +0,0 @@
-/*  GRAPHITE2 LICENSING
-
-    Copyright 2011, SIL International
-    All rights reserved.
-
-    This library is free software; you can redistribute it and/or modify
-    it under the terms of the GNU Lesser General Public License as published
-    by the Free Software Foundation; either version 2.1 of License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Lesser General Public License for more details.
-
-    You should also have received a copy of the GNU Lesser General Public
-    License along with this library in the file named "LICENSE".
-    If not, write to the Free Software Foundation, 51 Franklin Street,
-    suite 500, Boston, MA 02110-1335, USA or visit their web page on the 
-    internet at http://www.fsf.org/licenses/lgpl.html.
-
-Alternatively, the contents of this file may be used under the terms of the
-Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
-License, as published by the Free Software Foundation, either version 2
-of the License or (at your option) any later version.
-*/
-#include "inc/Main.h"
-#include "inc/Slot.h"
-#include "inc/Segment.h"
-#include "inc/Bidi.h"
-
-using namespace graphite2;
-
-enum DirCode {  // Hungarian: dirc
-        Unk        = -1,
-        N          =  0,   // other neutrals (default) - ON
-        L          =  1,   // left-to-right, strong - L
-        R          =  2,   // right-to-left, strong - R
-        AL         =  3,   // Arabic letter, right-to-left, strong, AR
-        EN         =  4,   // European number, left-to-right, weak - EN
-        EUS        =  5,   // European separator, left-to-right, weak - ES
-        ET         =  6,   // European number terminator, left-to-right, weak - ET
-        AN         =  7,   // Arabic number, left-to-right, weak - AN
-        CUS        =  8,   // Common number separator, left-to-right, weak - CS
-        WS         =  9,   // white space, neutral - WS
-        BN         = 10,   // boundary neutral - BN
-
-        LRO        = 11,   // LTR override
-        RLO        = 12,   // RTL override
-        LRE        = 13,   // LTR embedding
-        RLE        = 14,   // RTL embedding
-        PDF        = 15,   // pop directional format
-        NSM        = 16,   // non-space mark
-        LRI        = 17,   // LRI isolate
-        RLI        = 18,   // RLI isolate
-        FSI        = 19,   // FSI isolate
-        PDI        = 20,   // pop isolate
-        OPP        = 21,   // opening paired parenthesis
-        CPP        = 22,   // closing paired parenthesis
-
-        ON = N
-};
-
-enum DirMask {
-        WSflag = int8(1 << 7),     // keep track of WS for eos handling
-        WSMask = int8(~(1 << 7))
-};
-
-inline uint8    BaseClass(Slot *s)   { return s->getBidiClass() & WSMask; }
-
-unsigned int bidi_class_map[] = { 0, 1, 2, 5, 4, 8, 9, 3, 7, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0 };
-// Algorithms based on Unicode reference standard code. Thanks Asmus Freitag.
-
-void resolveWeak(Slot *start, int sos, int eos);
-void resolveNeutrals(Slot *s, int baseLevel, int sos, int eos);
-void processParens(Slot *s, Segment *seg, uint8 aMirror, int level, BracketPairStack &stack);
-
-inline int calc_base_level(Slot *s)
-{
-    int count = 0;
-    for ( ; s; s = s->next())
-    {
-        int cls = s->getBidiClass();
-        if (count)
-        {
-            switch(cls)
-            {
-            case LRI :
-            case RLI :
-            case FSI :
-                ++count;
-                break;
-            case PDI :
-                --count;
-            }
-        }
-        else
-        {
-            switch(cls)
-            {
-            case L :
-                return 0;
-            case R :
-            case AL :
-                return 1;
-            case LRI :
-            case RLI :
-            case FSI :
-                ++count;
-            }
-        }
-    }
-    return 0;
-}
-
-// inline or not?
-void do_resolves(Slot *start, int level, int sos, int eos, int &bmask, Segment *seg, uint8 aMirror, BracketPairStack &stack)
-{
-    if (bmask & 0x1F1178)
-        resolveWeak(start, sos, eos);
-    if (bmask & 0x200000)
-        processParens(start, seg, aMirror, level, stack);
-    if (bmask & 0x7E0361)
-        resolveNeutrals(start, level, sos, eos);
-    bmask = 0;
-}
-
-enum maxs
-{
-    MAX_LEVEL = 125,
-};
-
-// returns where we are up to in processing
-Slot *process_bidi(Slot *start, int level, int prelevel, int &nextLevel, int dirover, int isol, int &cisol, int &isolerr, int &embederr, int init, Segment *seg, uint8 aMirror, BracketPairStack &bstack)
-{
-    int bmask = 0;
-    Slot *s = start;
-    Slot *slast = start;
-    Slot *scurr = 0;
-    Slot *stemp;
-    int lnextLevel = nextLevel;
-    int newLevel;
-    int empty = 1;
-    for ( ; s; s = s ? s->next() : s)
-    {
-        int cls = s->getBidiClass();
-        bmask |= (1 << cls);
-        s->setBidiLevel(level);
-        // we keep s->prev() pointing backwards for PDI repeating
-        
-        switch (cls)
-        {
-        case BN :
-            if (slast == s) slast = s->next();      // ignore if at front of text
-            continue;
-        case LRE :
-        case LRO :
-        case RLE :
-        case RLO :
-            switch (cls)
-            {
-            case LRE :
-            case LRO :
-                newLevel = level + (level & 1 ? 1 : 2);
-                break;
-            case RLE :
-            case RLO :
-                newLevel = level + (level & 1 ? 2 : 1);
-                break;
-            }
-            s->setBidiClass(BN);
-            if (isolerr || newLevel > MAX_LEVEL || embederr)
-            {
-                if (!isolerr) ++embederr;
-                break;
-            }
-            stemp = scurr;
-            if (scurr)
-                scurr->prev(0);         // don't include control in string
-            lnextLevel = newLevel;
-            scurr = s;
-            s->setBidiLevel(newLevel); // to make it vanish
-            // recurse for the new subsequence. A sequence only contains text at the same level
-            s = process_bidi(s->next(), newLevel, level, lnextLevel, cls < LRE, 0, cisol, isolerr, embederr, 0, seg, aMirror, bstack);
-            // s points at PDF or end of sequence
-            // try to keep extending the run and not process it until we have to
-            if (lnextLevel != level || !s)      // if the subsequence really had something in it, or we are at the end of the run
-            {
-                if (slast != scurr)             // process the run now, don't try to extend it
-                {
-                    // process text preceeding embedding
-                    do_resolves(slast, level, (prelevel > level ? prelevel : level) & 1, lnextLevel & 1, bmask, seg, aMirror, bstack);
-                    empty = 0;
-                    nextLevel = level;
-                }
-                else if (lnextLevel != level)   // the subsequence had something
-                {
-                    empty = 0;                  // so we aren't empty either
-                    nextLevel = lnextLevel;     // but since we really are empty, pass back our level from the subsequence
-                }
-                if (s)                          // if still more to process
-                {
-                    prelevel = lnextLevel;      // future text starts out with sos of the higher subsequence
-                    lnextLevel = level;         // and eos is our level
-                }
-                slast = s ? s->next() : s;
-            }
-            else if (stemp)
-                stemp->prev(s);
-            break;
-
-        case PDF :
-            s->setBidiClass(BN);
-            s->prev(0);                         // unstitch us since we skip final stitching code when we return
-            if (isol || isolerr || init)        // boundary error conditions
-                break;
-            if (embederr)
-            {
-                --embederr;
-                break;
-            }
-            if (slast != s)
-            {
-                scurr->prev(0);     // if slast, then scurr. Terminate before here
-                do_resolves(slast, level, level & 1, level & 1, bmask, seg, aMirror, bstack);
-                empty = 0;
-            }
-            if (empty)
-            {
-                nextLevel = prelevel;       // no contents? set our level to that of parent
-                s->setBidiLevel(prelevel);
-            }
-            return s;
-
-        case FSI :
-        case LRI :
-        case RLI :
-            switch (cls)
-            {
-            case FSI :
-                if (calc_base_level(s->next()))
-                    newLevel = level + (level & 1 ? 2 : 1);
-                else
-                    newLevel = level + (level & 1 ? 1 : 2);
-                break;
-            case LRI :
-                newLevel = level + (level & 1 ? 1 : 2);
-                break;
-            case RLI :
-                newLevel = level + (level & 1 ? 2 : 1);
-                break;
-            }
-            if (newLevel > MAX_LEVEL || isolerr)
-            {
-                ++isolerr;
-                s->setBidiClass(ON | WSflag);
-                break;
-            }
-            ++cisol;
-            if (scurr) scurr->prev(s);
-            scurr = s;  // include FSI
-            lnextLevel = newLevel;
-            // recurse for the new sub sequence
-            s = process_bidi(s->next(), newLevel, newLevel, lnextLevel, 0, 1, cisol, isolerr, embederr, 0, seg, aMirror, bstack);
-            // s points at PDI
-            if (s)
-            {
-                bmask |= 1 << BaseClass(s);     // include the PDI in the mask
-                s->setBidiLevel(level);         // reset its level to our level
-            }
-            lnextLevel = level;
-            break;
-
-        case PDI :
-            if (isolerr)
-            {
-                --isolerr;
-                s->setBidiClass(ON | WSflag);
-                break;
-            }
-            if (init || !cisol)
-            {
-                s->setBidiClass(ON | WSflag);
-                break;
-            }
-            embederr = 0;
-            if (!isol)                  // we are in an embedded subsequence, we have to return through all those
-            {
-                if (empty)              // if empty, reset the level to tell embedded parent
-                    nextLevel = prelevel;
-                return s->prev();       // keep working up the stack pointing at this PDI until we get to an isolate entry
-            }
-            else                        // we are terminating an isolate sequence
-            {
-                if (slast != s)         // process any remaining content in this subseqence
-                {
-                    scurr->prev(0);
-                    do_resolves(slast, level, prelevel & 1, level & 1, bmask, seg, aMirror, bstack);
-                }
-                --cisol;                // pop the isol sequence from the stack
-                return s;
-            }
-
-        default :
-            if (dirover)
-                s->setBidiClass((level & 1 ? R : L) | (WSflag * (cls == WS)));
-        }
-        if (s) s->prev(0);      // unstitch us
-        if (scurr)              // stitch in text for processing
-            scurr->prev(s);
-        scurr = s;              // add us to text to process
-    }
-    if (slast != s)
-    {
-        do_resolves(slast, level, (level > prelevel ? level : prelevel) & 1, lnextLevel & 1, bmask, seg, aMirror, bstack);
-        empty = 0;
-    }
-    if (empty || isol)
-        nextLevel = prelevel;
-    return s;
-}
-
-// === RESOLVE WEAK TYPES ================================================
-
-enum bidi_state // possible states
-{
-        xa,             //      arabic letter
-        xr,             //      right leter
-        xl,             //      left letter
-
-        ao,             //      arabic lett. foll by ON
-        ro,             //      right lett. foll by ON
-        lo,             //      left lett. foll by ON
-
-        rt,             //      ET following R
-        lt,             //      ET following L
-
-        cn,             //      EN, AN following AL
-        ra,             //      arabic number foll R
-        re,             //      european number foll R
-        la,             //      arabic number foll L
-        le,             //      european number foll L
-
-        ac,             //      CS following cn
-        rc,             //      CS following ra
-        rs,             //      CS,ES following re
-        lc,             //      CS following la
-        ls,             //      CS,ES following le
-
-        ret,            //      ET following re
-        let,            //      ET following le
-} ;
-
-const bidi_state stateWeak[][10] =
-{
-        //      N,  L,  R,  AN, EN, AL,NSM, CS, ES, ET,
-{ /*xa*/        ao, xl, xr, cn, cn, xa, xa, ao, ao, ao, /* arabic letter          */ },
-{ /*xr*/        ro, xl, xr, ra, re, xa, xr, ro, ro, rt, /* right letter           */ },
-{ /*xl*/        lo, xl, xr, la, le, xa, xl, lo, lo, lt, /* left letter            */ },
-
-{ /*ao*/        ao, xl, xr, cn, cn, xa, ao, ao, ao, ao, /* arabic lett. foll by ON*/ },
-{ /*ro*/        ro, xl, xr, ra, re, xa, ro, ro, ro, rt, /* right lett. foll by ON */ },
-{ /*lo*/        lo, xl, xr, la, le, xa, lo, lo, lo, lt, /* left lett. foll by ON  */ },
-
-{ /*rt*/        ro, xl, xr, ra, re, xa, rt, ro, ro, rt, /* ET following R         */ },
-{ /*lt*/        lo, xl, xr, la, le, xa, lt, lo, lo, lt, /* ET following L         */ },
-
-{ /*cn*/        ao, xl, xr, cn, cn, xa, cn, ac, ao, ao, /* EN, AN following AL    */ },
-{ /*ra*/        ro, xl, xr, ra, re, xa, ra, rc, ro, rt, /* arabic number foll R   */ },
-{ /*re*/        ro, xl, xr, ra, re, xa, re, rs, rs,ret, /* european number foll R */ },
-{ /*la*/        lo, xl, xr, la, le, xa, la, lc, lo, lt, /* arabic number foll L   */ },
-{ /*le*/        lo, xl, xr, la, le, xa, le, ls, ls,let, /* european number foll L */ },
-
-{ /*ac*/        ao, xl, xr, cn, cn, xa, ao, ao, ao, ao, /* CS following cn        */ },
-{ /*rc*/        ro, xl, xr, ra, re, xa, ro, ro, ro, rt, /* CS following ra        */ },
-{ /*rs*/        ro, xl, xr, ra, re, xa, ro, ro, ro, rt, /* CS,ES following re     */ },
-{ /*lc*/        lo, xl, xr, la, le, xa, lo, lo, lo, lt, /* CS following la        */ },
-{ /*ls*/        lo, xl, xr, la, le, xa, lo, lo, lo, lt, /* CS,ES following le     */ },
-
-{ /*ret*/       ro, xl, xr, ra, re, xa,ret, ro, ro,ret, /* ET following re        */ },
-{ /*let*/       lo, xl, xr, la, le, xa,let, lo, lo,let, /* ET following le        */ },
-
-
-};
-
-enum bidi_action // possible actions
-{
-        // primitives
-        IX = 0x100,                     // increment
-        XX = 0xF,                       // no-op
-
-        // actions
-        xxx = (XX << 4) + XX,           // no-op
-        xIx = IX + xxx,                         // increment run
-        xxN = (XX << 4) + ON,           // set current to N
-        xxE = (XX << 4) + EN,           // set current to EN
-        xxA = (XX << 4) + AN,           // set current to AN
-        xxR = (XX << 4) + R,            // set current to R
-        xxL = (XX << 4) + L,            // set current to L
-        Nxx = (ON << 4) + 0xF,          // set run to neutral
-        Axx = (AN << 4) + 0xF,          // set run to AN
-        ExE = (EN << 4) + EN,           // set run to EN, set current to EN
-        NIx = (ON << 4) + 0xF + IX,     // set run to N, increment
-        NxN = (ON << 4) + ON,           // set run to N, set current to N
-        NxR = (ON << 4) + R,            // set run to N, set current to R
-        NxE = (ON << 4) + EN,           // set run to N, set current to EN
-
-        AxA = (AN << 4) + AN,           // set run to AN, set current to AN
-        NxL = (ON << 4) + L,            // set run to N, set current to L
-        LxL = (L << 4) + L,             // set run to L, set current to L
-};
-
-
-const bidi_action actionWeak[][10] =
-{
-    //   N,.. L,   R,   AN,  EN,  AL,  NSM, CS,..ES,  ET,
-{ /*xa*/ xxx, xxx, xxx, xxx, xxA, xxR, xxR, xxN, xxN, xxN, /* arabic letter             */ },
-{ /*xr*/ xxx, xxx, xxx, xxx, xxE, xxR, xxR, xxN, xxN, xIx, /* right leter               */ },
-{ /*xl*/ xxx, xxx, xxx, xxx, xxL, xxR, xxL, xxN, xxN, xIx, /* left letter               */ },
-
-{ /*ao*/ xxx, xxx, xxx, xxx, xxA, xxR, xxN, xxN, xxN, xxN, /* arabic lett. foll by ON   */ },
-{ /*ro*/ xxx, xxx, xxx, xxx, xxE, xxR, xxN, xxN, xxN, xIx, /* right lett. foll by ON    */ },
-{ /*lo*/ xxx, xxx, xxx, xxx, xxL, xxR, xxN, xxN, xxN, xIx, /* left lett. foll by ON     */ },
-
-{ /*rt*/ Nxx, Nxx, Nxx, Nxx, ExE, NxR, xIx, NxN, NxN, xIx, /* ET following R            */ },
-{ /*lt*/ Nxx, Nxx, Nxx, Nxx, LxL, NxR, xIx, NxN, NxN, xIx, /* ET following L            */ },
-
-{ /*cn*/ xxx, xxx, xxx, xxx, xxA, xxR, xxA, xIx, xxN, xxN, /* EN, AN following  AL      */ },
-{ /*ra*/ xxx, xxx, xxx, xxx, xxE, xxR, xxA, xIx, xxN, xIx, /* arabic number foll R      */ },
-{ /*re*/ xxx, xxx, xxx, xxx, xxE, xxR, xxE, xIx, xIx, xxE, /* european number foll R    */ },
-{ /*la*/ xxx, xxx, xxx, xxx, xxL, xxR, xxA, xIx, xxN, xIx, /* arabic number foll L      */ },
-{ /*le*/ xxx, xxx, xxx, xxx, xxL, xxR, xxL, xIx, xIx, xxL, /* european number foll L    */ },
-
-{ /*ac*/ Nxx, Nxx, Nxx, Axx, AxA, NxR, NxN, NxN, NxN, NxN, /* CS following cn           */ },
-{ /*rc*/ Nxx, Nxx, Nxx, Axx, NxE, NxR, NxN, NxN, NxN, NIx, /* CS following ra           */ },
-{ /*rs*/ Nxx, Nxx, Nxx, Nxx, ExE, NxR, NxN, NxN, NxN, NIx, /* CS,ES following re        */ },
-{ /*lc*/ Nxx, Nxx, Nxx, Axx, NxL, NxR, NxN, NxN, NxN, NIx, /* CS following la           */ },
-{ /*ls*/ Nxx, Nxx, Nxx, Nxx, LxL, NxR, NxN, NxN, NxN, NIx, /* CS,ES following le        */ },
-
-{ /*ret*/xxx, xxx, xxx, xxx, xxE, xxR, xxE, xxN, xxN, xxE, /* ET following re           */ },
-{ /*let*/xxx, xxx, xxx, xxx, xxL, xxR, xxL, xxN, xxN, xxL, /* ET following le           */ },
-};
-
-inline uint8    GetDeferredType(bidi_action a)          { return (a >> 4) & 0xF; }
-inline uint8    GetResolvedType(bidi_action a)          { return a & 0xF; }
-inline DirCode  EmbeddingDirection(int l)               { return l & 1 ? R : L; }
-
-// Neutrals
-enum neutral_action
-{
-        // action to resolve previous input
-        nL = L,         // resolve EN to L
-        En = 3 << 4,    // resolve neutrals run to embedding level direction
-        Rn = R << 4,    // resolve neutrals run to strong right
-        Ln = L << 4,    // resolved neutrals run to strong left
-        In = (1<<8),    // increment count of deferred neutrals
-        LnL = (1<<4)+L, // set run and EN to L
-};
-
-// ->prev() here means ->next()
-void SetDeferredRunClass(Slot *s, Slot *sRun, int nval)
-{
-    if (!sRun || s == sRun) return;
-    for (Slot *p = sRun; p != s; p = p->prev())
-        if (p->getBidiClass() == WS) p->setBidiClass(nval | WSflag);
-        else if (BaseClass(p) != BN) p->setBidiClass(nval | (p->getBidiClass() & WSflag));
-}
-
-void SetThisDeferredRunClass(Slot *s, Slot *sRun, int nval)
-{
-    if (!sRun) return;
-    for (Slot *p = sRun, *e = s->prev(); p != e; p = p->prev())
-        if (p->getBidiClass() == WS) p->setBidiClass(nval | WSflag);
-        else if (BaseClass(p) != BN) p->setBidiClass(nval | (p->getBidiClass() & WSflag));
-}
-
-void resolveWeak(Slot *start, int sos, int eos)
-{
-    int state = (sos & 1) ? xr : xl;
-    int cls;
-    Slot *s = start;
-    Slot *sRun = NULL;
-    Slot *sLast = s;
-
-    for ( ; s; s = s->prev())
-    {
-        sLast = s;
-        cls = BaseClass(s);
-        switch (cls)
-        {
-        case BN :
-            if (s == start) start = s->prev();  // skip initial BNs for NSM resolving
-            continue;
-        case LRI :
-        case RLI :
-        case FSI :
-        case PDI :
-            {
-                Slot *snext = s->prev();
-                if (snext && snext->getBidiClass() == NSM)
-                    snext->setBidiClass(ON);
-                s->setBidiClass(ON | WSflag);
-            }
-            break;
-
-        case NSM :
-            if (s == start)
-            {
-                cls = EmbeddingDirection(sos);
-                s->setBidiClass(cls);
-            }
-            break;
-        }
-        
-        bidi_action action = actionWeak[state][bidi_class_map[cls]];
-        int clsRun = GetDeferredType(action);
-        if (clsRun != XX)
-        {
-            SetDeferredRunClass(s, sRun, clsRun);
-            sRun = NULL;
-        }
-        int clsNew = GetResolvedType(action);
-        if (clsNew != XX)
-            s->setBidiClass(clsNew);
-        if (!sRun && (IX & action))
-            sRun = s;
-        state = stateWeak[state][bidi_class_map[cls]];
-    }
-
-    cls = EmbeddingDirection(eos);
-    int clsRun = GetDeferredType(actionWeak[state][bidi_class_map[cls]]);
-    if (clsRun != XX)
-        SetThisDeferredRunClass(sLast, sRun, clsRun);
-}
-
-void processParens(Slot *s, Segment *seg, uint8 aMirror, int level, BracketPairStack &stack)
-{
-    uint8 mask = 0;
-    int8 lastDir = -1;
-    BracketPair *p;
-    for ( ; s; s = s->prev())       // walk the sequence
-    {
-        uint16 ogid = seg->glyphAttr(s->gid(), aMirror) || s->gid();
-        int cls = BaseClass(s);
-        
-        switch(cls)
-        {
-        case OPP :
-            stack.orin(mask);
-            stack.push(ogid, s, lastDir, lastDir != CPP);
-            mask = 0;
-            lastDir = OPP;
-            break;
-        case CPP :
-            stack.orin(mask);
-            p = stack.scan(s->gid());
-            if (!p) break;
-            mask = 0;
-            stack.close(p, s);
-            lastDir = CPP;
-            break;
-        case L :
-            lastDir = L;
-            mask |= 1;
-            break;
-        case R :
-        case AL :
-        case AN :
-        case EN :
-            lastDir = R;
-            mask |= 2;
-        }
-    }
-    if (stack.size())
-    {
-        for (p = stack.start(); p; p =p->next())      // walk the stack
-        {
-            if (p->close() && p->mask())
-            {
-                int dir = (level & 1) + 1;
-                if (p->mask() & dir)
-                { }
-                else if (p->mask() & (1 << (~level & 1)))  // if inside has strong other embedding
-                {
-                    int ldir = p->before();
-                    if ((p->before() == OPP || p->before() == CPP) && p->prev())
-                    {
-                        for (BracketPair *q = p->prev(); q; q = q->prev())
-                        {
-                            ldir = q->open()->getBidiClass();
-                            if (ldir < 3) break;
-                            ldir = q->before();
-                            if (ldir < 3) break;
-                        }
-                        if (ldir > 2) ldir = 0;
-                    }
-                    if (ldir > 0 && (ldir - 1) != (level & 1))     // is dir given opp. to level dir (ldir == R or L)
-                        dir = (~level & 1) + 1;
-                }
-                p->open()->setBidiClass(dir);
-                p->close()->setBidiClass(dir);
-            }
-        }
-        stack.clear();
-    }
-}
-
-int GetDeferredNeutrals(int action, int level)
-{
-        action = (action >> 4) & 0xF;
-        if (action == (En >> 4))
-            return EmbeddingDirection(level);
-        else
-            return action;
-}
-
-int GetResolvedNeutrals(int action)
-{
-        return action & 0xF;
-}
-
-// state values
-enum neutral_state
-{
-        // new temporary class
-        r,  // R and characters resolved to R
-        l,  // L and characters resolved to L
-        rn, // N preceded by right
-        ln, // N preceded by left
-        a,  // AN preceded by left (the abbrev 'la' is used up above)
-        na, // N preceeded by a
-} ;
-
-const uint8 neutral_class_map[] = { 0, 1, 2, 0, 4, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
-
-const int actionNeutrals[][5] =
-{
-// cls= N,   L,  R, AN, EN,        state =
-{       In,  0,  0,  0,  0, },  // r    right
-{       In,  0,  0,  0,  L, },  // l    left
-
-{       In, En, Rn, Rn, Rn, },  // rn   N preceded by right
-{       In, Ln, En, En, LnL, }, // ln   N preceded by left
-
-{       In,  0,  0,  0,  L, },  // a   AN preceded by left
-{       In, En, Rn, Rn, En, },  // na   N  preceded by a
-} ;
-
-const int stateNeutrals[][5] =
-{
-// cls= N,  L,  R,      AN,     EN              state =
-{       rn, l,  r,      r,      r, },           // r   right
-{       ln, l,  r,      a,      l, },           // l   left
-
-{       rn, l,  r,      r,      r, },           // rn  N preceded by right
-{       ln, l,  r,      a,      l, },           // ln  N preceded by left
-
-{       na, l,  r,      a,      l, },           // a  AN preceded by left
-{       na, l,  r,      a,      l, },           // na  N preceded by la
-} ;
-
-void resolveNeutrals(Slot *s, int baseLevel, int sos, int eos)
-{
-    int state = (sos & 1) ? r : l;
-    int cls;
-    Slot *sRun = NULL;
-    Slot *sLast = s;
-    int level = baseLevel;
-
-    for ( ; s; s = s->prev())
-    {
-        sLast = s;
-        cls = BaseClass(s);
-        switch (cls)
-        {
-        case BN :
-            continue;
-        case LRI :
-        case RLI :
-        case FSI :
-            s->setBidiClass(BN | WSflag);
-            continue;
-
-        default :
-            int action = actionNeutrals[state][neutral_class_map[cls]];
-            int clsRun = GetDeferredNeutrals(action, level);
-            if (clsRun != N)
-            {
-                SetDeferredRunClass(s, sRun, clsRun);
-                sRun = NULL;
-            }
-            int clsNew = GetResolvedNeutrals(action);
-            if (clsNew != N)
-                s->setBidiClass(clsNew);
-            if (!sRun && (action & In))
-                sRun = s;
-            state = stateNeutrals[state][neutral_class_map[cls]];
-        }
-    }
-    cls = EmbeddingDirection(eos);
-    int clsRun = GetDeferredNeutrals(actionNeutrals[state][neutral_class_map[cls]], level);
-    if (clsRun != N)
-        SetThisDeferredRunClass(sLast, sRun, clsRun);
-}
-
-const int addLevel[][4] =
-{
-        //  cls = L,    R,      AN,     EN         level =
-/* even */      { 0,    1,      2,      2, },   // EVEN
-/* odd  */      { 1,    0,      1,      1, },   // ODD
-
-};
-
-void resolveImplicit(Slot *s, Segment *seg, uint8 aMirror)
-{
-    bool rtl = seg->dir() & 1;
-    int level = rtl;
-    Slot *slast = 0;
-    for ( ; s; s = s->next())
-    {
-        int cls = BaseClass(s);
-        s->prev(slast);         // restitch the prev() side of the doubly linked list
-        slast = s;
-        if (cls == AN)
-            cls = AL;   // use AL value as the index for AN, no property change
-        if (cls < 5 && cls > 0)
-        {
-            level = s->getBidiLevel();
-            level += addLevel[level & 1][cls - 1];
-            s->setBidiLevel(level);
-        }
-        if (aMirror)
-        {
-            int hasChar = seg->glyphAttr(s->gid(), aMirror + 1);
-            if ( ((level & 1) && (!(seg->dir() & 4) || !hasChar)) 
-              || ((rtl ^ (level & 1)) && (seg->dir() & 4) && hasChar) )
-            {
-                unsigned short g = seg->glyphAttr(s->gid(), aMirror);
-                if (g) s->setGlyph(seg, g);
-            }
-        }
-    }
-}
-
-void resolveWhitespace(int baseLevel, Slot *s)
-{
-    for ( ; s; s = s->prev())
-    {
-        int8 cls = s->getBidiClass();
-        if (cls == WS || (cls & WSflag))
-            s->setBidiLevel(baseLevel);
-        else if (cls != BN)
-            break;
-    }
-}
-
-
-/*
-Stitch two spans together to make another span (with ends tied together).
-If the level is odd then swap the order of the two spans
-*/
-inline
-Slot * join(int level, Slot * a, Slot * b)
-{
-    if (!a) return b;
-    if (level & 1)  { Slot * const t = a; a = b; b = t; }
-    Slot * const t = b->prev();
-    a->prev()->next(b); b->prev(a->prev()); // splice middle
-    t->next(a); a->prev(t);                 // splice ends
-    return a;
-}
-
-/*
-Given the first slot in a run of slots with the same bidi level, turn the run
-into it's own little doubly linked list ring (a span) with the two ends joined together.
-If the run is rtl then reverse its direction.
-Returns the first slot after the span
-*/
-Slot * span(Slot * & cs, const bool rtl)
-{
-    Slot * r = cs, * re = cs; cs = cs->next();
-    if (rtl)
-    {
-        Slot * t = r->next(); r->next(r->prev()); r->prev(t);
-        for (int l = r->getBidiLevel(); cs && (l == cs->getBidiLevel() || cs->getBidiClass() == BN); cs = cs->prev())
-        {
-            re = cs;
-            t = cs->next(); cs->next(cs->prev()); cs->prev(t);
-        }
-        r->next(re);
-        re->prev(r);
-        r = re;
-    }
-    else
-    {
-        for (int l = r->getBidiLevel(); cs && (l == cs->getBidiLevel() || cs->getBidiClass() == BN); cs = cs->next())
-            re = cs;
-        r->prev(re);
-        re->next(r);
-    }
-    if (cs) cs->prev(0);
-    return r;
-}
-
-inline int getlevel(const Slot *cs, const int level)
-{
-    while (cs && cs->getBidiClass() == BN)
-    { cs = cs->next(); }
-    if (cs)
-        return cs->getBidiLevel();
-    else
-        return level;
-}
-
-Slot *resolveOrder(Slot * & cs, const bool reordered, const int level)
-{
-    Slot * r = 0;
-    int ls;
-    while (cs && level <= (ls = getlevel(cs, level) - reordered))
-    {
-        r = join(level, r, level < ls
-                                ? resolveOrder(/* updates */cs, reordered, level+1) // find span of heighest level
-                                : span(/* updates */cs, level & 1));
-    }
-    return r;
-}
diff --git a/gfx/graphite2/src/Collider.cpp b/gfx/graphite2/src/Collider.cpp
index 2df46ebc4de8..ba59d9231bee 100644
--- a/gfx/graphite2/src/Collider.cpp
+++ b/gfx/graphite2/src/Collider.cpp
@@ -306,6 +306,7 @@ bool ShiftCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShif
         float seq_above_wt = cslot->seqAboveWt();
         float seq_below_wt = cslot->seqBelowWt();
         float seq_valign_wt = cslot->seqValignWt();
+        float lmargin = _margin;
         // if isAfter, invert orderFlags for diagonal orders.
         if (isAfter)
         {
@@ -334,6 +335,7 @@ bool ShiftCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShif
                     torg = _currOffset.x;
                     cmin = _limit.bl.x + torg;
                     cmax = _limit.tr.x - tbb.xi + tbb.xa + torg;
+                    lmargin = _margin;
                     break;
                 case 1 :	// y direction
                     vmin = max(max(bb.yi - tbb.ya + sy, tsb.di - sb.da + tx - sd), sb.si - tsb.sa - tx + ss);
@@ -345,6 +347,7 @@ bool ShiftCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShif
                     torg = _currOffset.y;
                     cmin = _limit.bl.y + torg;
                     cmax = _limit.tr.y - tbb.yi + tbb.ya + torg;
+                    lmargin = _margin;
                     break;
                 case 2 :    // sum - moving along the positively-sloped vector, so the boundaries are the
                             // negatively-sloped boundaries.
@@ -357,6 +360,7 @@ bool ShiftCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShif
                     torg = _currOffset.x + _currOffset.y;
                     cmin = _limit.bl.x + _limit.bl.y + torg;
                     cmax = _limit.tr.x + _limit.tr.y - tsb.si + tsb.sa + torg;
+                    lmargin = _margin / ISQRT2;
                     break;
                 case 3 :    // diff - moving along the negatively-sloped vector, so the boundaries are the
                             // positively-sloped boundaries.
@@ -369,6 +373,7 @@ bool ShiftCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShif
                     torg = _currOffset.x - _currOffset.y;
                     cmin = _limit.bl.x - _limit.tr.y + torg;
                     cmax = _limit.tr.x - _limit.bl.y - tsb.di + tsb.da + torg;
+                    lmargin = _margin / ISQRT2;
                     break;
                 default :
                     continue;
@@ -470,7 +475,7 @@ bool ShiftCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShif
                 }
             }
 
-            if (vmax < cmin - _margin || vmin > cmax + _margin || omax < otmin - _margin || omin > otmax + _margin)
+            if (vmax < cmin - lmargin || vmin > cmax + lmargin || omax < otmin - lmargin || omin > otmax + lmargin)
                 continue;
 
             // Process sub-boxes that are defined for this glyph.
@@ -509,7 +514,7 @@ bool ShiftCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShif
                             omax = ssb.sa + ss;
                             break;
                     }
-                    if (vmax < cmin - _margin || vmin > cmax + _margin || omax < otmin - _margin || omin > otmax + _margin)
+                    if (vmax < cmin - lmargin || vmin > cmax + lmargin || omax < otmin - lmargin || omin > otmax + lmargin)
                         continue;
 
 #if !defined GRAPHITE2_NTRACING
@@ -517,11 +522,11 @@ bool ShiftCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShif
                         dbgout->setenv(1, reinterpret_cast<void *>(j));
 #endif
                     if (omin > otmax)
-                        _ranges[i].weightedAxis(i, vmin - _margin, vmax + _margin, 0, 0, 0, 0, 0,
-                                                sqr(_margin - omin + otmax) * _marginWt, false);
+                        _ranges[i].weightedAxis(i, vmin - lmargin, vmax + lmargin, 0, 0, 0, 0, 0,
+                                                sqr(lmargin - omin + otmax) * _marginWt, false);
                     else if (omax < otmin)
-                        _ranges[i].weightedAxis(i, vmin - _margin, vmax + _margin, 0, 0, 0, 0, 0,
-                                                sqr(_margin - otmin + omax) * _marginWt, false);
+                        _ranges[i].weightedAxis(i, vmin - lmargin, vmax + lmargin, 0, 0, 0, 0, 0,
+                                                sqr(lmargin - otmin + omax) * _marginWt, false);
                     else
                         _ranges[i].exclude_with_margins(vmin, vmax, i);
                     anyhits = true;
@@ -537,11 +542,11 @@ bool ShiftCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShif
 #endif
                 isCol = true;
                 if (omin > otmax)
-                    _ranges[i].weightedAxis(i, vmin - _margin, vmax + _margin, 0, 0, 0, 0, 0,
-                                            sqr(_margin - omin + otmax) * _marginWt, false);
+                    _ranges[i].weightedAxis(i, vmin - lmargin, vmax + lmargin, 0, 0, 0, 0, 0,
+                                            sqr(lmargin - omin + otmax) * _marginWt, false);
                 else if (omax < otmin)
-                    _ranges[i].weightedAxis(i, vmin - _margin, vmax + _margin, 0, 0, 0, 0, 0,
-                                            sqr(_margin - otmin + omax) * _marginWt, false);
+                    _ranges[i].weightedAxis(i, vmin - lmargin, vmax + lmargin, 0, 0, 0, 0, 0,
+                                            sqr(lmargin - otmin + omax) * _marginWt, false);
                 else
                     _ranges[i].exclude_with_margins(vmin, vmax, i);
 
@@ -752,7 +757,7 @@ static float localmin(float al, float au, float bl, float bu, float x)
 }
 
 // Return the given edge of the glyph at height y, taking any slant box into account.
-static float get_edge(Segment *seg, const Slot *s, const Position &shift, float y, float width, bool isRight)
+static float get_edge(Segment *seg, const Slot *s, const Position &shift, float y, float width, float margin, bool isRight)
 {
     const GlyphCache &gc = seg->getFace()->glyphs();
     unsigned short gid = s->gid();
@@ -767,15 +772,15 @@ static float get_edge(Segment *seg, const Slot *s, const Position &shift, float
         {
             const BBox &sbb = gc.getSubBoundingBBox(gid, i);
             const SlantBox &ssb = gc.getSubBoundingSlantBox(gid, i);
-            if (sy + sbb.yi > y + width / 2 || sy + sbb.ya < y - width / 2)
+            if (sy + sbb.yi - margin > y + width / 2 || sy + sbb.ya + margin < y - width / 2)
                 continue;
             if (isRight)
             {
-                float x = sx + sbb.xa;
+                float x = sx + sbb.xa + margin;
                 if (x > res)
                 {
-                    float td = sx - sy + ssb.da + y;
-                    float ts = sx + sy + ssb.sa - y;
+                    float td = sx - sy + ssb.da + margin + y;
+                    float ts = sx + sy + ssb.sa + margin - y;
                     x = localmax(td - width / 2, td + width / 2,  ts - width / 2, ts + width / 2, x);
                     if (x > res)
                         res = x;
@@ -783,11 +788,11 @@ static float get_edge(Segment *seg, const Slot *s, const Position &shift, float
             }
             else
             {
-                float x = sx + sbb.xi;
+                float x = sx + sbb.xi - margin;
                 if (x < res)
                 {
-                    float td = sx - sy + ssb.di + y;
-                    float ts = sx + sy + ssb.si - y;
+                    float td = sx - sy + ssb.di - margin + y;
+                    float ts = sx + sy + ssb.si - margin - y;
                     x = localmin(td - width / 2, td + width / 2, ts - width / 2, ts + width / 2, x);
                     if (x < res)
                         res = x;
@@ -802,9 +807,9 @@ static float get_edge(Segment *seg, const Slot *s, const Position &shift, float
         float td = sx - sy + y;
         float ts = sx + sy - y;
         if (isRight)
-            res = localmax(td + sb.da - width / 2, td + sb.da + width / 2, ts + sb.sa - width / 2, ts + sb.sa + width / 2, sx + bb.xa);
+            res = localmax(td + sb.da - width / 2, td + sb.da + width / 2, ts + sb.sa - width / 2, ts + sb.sa + width / 2, sx + bb.xa) + margin;
         else
-            res = localmin(td + sb.di - width / 2, td + sb.di + width / 2, ts + sb.si - width / 2, ts + sb.si + width / 2, sx + bb.xi);
+            res = localmin(td + sb.di - width / 2, td + sb.di + width / 2, ts + sb.si - width / 2, ts + sb.si + width / 2, sx + bb.xi) - margin;
     }
     return res;
 }
@@ -865,6 +870,7 @@ bool KernCollider::initSlot(Segment *seg, Slot *aSlot, const Rect &limit, float
                     _edges.pop_back();
             }
         }
+        goto done;
     }
     numSlices = _edges.size();
 
@@ -896,7 +902,7 @@ bool KernCollider::initSlot(Segment *seg, Slot *aSlot, const Rect &limit, float
             float y = _miny - 1 + (i + .5f) * _sliceWidth; // vertical center of slice
             if ((dir & 1) && x < _edges[i])
             {
-                t = get_edge(seg, s, c->shift(), y, _sliceWidth, false);
+                t = get_edge(seg, s, c->shift(), y, _sliceWidth, margin, false);
                 if (t < _edges[i])
                 {
                     _edges[i] = t;
@@ -906,7 +912,7 @@ bool KernCollider::initSlot(Segment *seg, Slot *aSlot, const Rect &limit, float
             }
             else if (!(dir & 1) && x > _edges[i])
             {
-                t = get_edge(seg, s, c->shift(), y, _sliceWidth, true);
+                t = get_edge(seg, s, c->shift(), y, _sliceWidth, margin, true);
                 if (t > _edges[i])
                 {
                     _edges[i] = t;
@@ -916,6 +922,7 @@ bool KernCollider::initSlot(Segment *seg, Slot *aSlot, const Rect &limit, float
             }
         }
     }
+    done:
     _mingap = (float)1e38;
     _target = aSlot;
     _margin = margin;
@@ -946,22 +953,17 @@ bool KernCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShift
     if (smin > smax)
         return false;
     bool collides = false;
-    float below = smin > 0 ? _edges[smin-1] * rtl : 1e38f;
-    float here = _edges[smin] * rtl;
-    float above = smin < (int)_edges.size() - 1 ? _edges[smin+1] * rtl : 1e38f;
 
     for (int i = smin; i <= smax; ++i)
     {
         float t;
+        float here = _edges[i] * rtl;
         float y = (float)(_miny - 1 + (i + .5f) * _sliceWidth);  // vertical center of slice
-        if (    (x > here - _mingap - currSpace)
-             || (x > below - _mingap - currSpace)
-             || (x > above - _mingap - currSpace))
+        if (    (x > here - _mingap - currSpace) )
         {
             // 2 * currSpace to account for the space that is already separating them and the space we want to add
-            float m = get_edge(seg, slot, currShift, y, _sliceWidth, rtl > 0) * rtl + 2 * currSpace;
-            // Check slices above and below (if any).
-            t = min(min(here, below), above) - m;
+            float m = get_edge(seg, slot, currShift, y, _sliceWidth, 0., rtl > 0) * rtl + 2 * currSpace;
+            t = here - m;
             // _mingap is positive to shrink
             if (t < _mingap)
             {
@@ -977,8 +979,6 @@ bool KernCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShift
             }
 #endif
         }
-        below = here; here = above;
-        above = i < (int)_edges.size() - 2 ? _edges[i+2] * rtl : 1e38f;
     }
     return collides;   // note that true is not a necessarily reliable value
     
@@ -987,9 +987,10 @@ bool KernCollider::mergeSlot(Segment *seg, Slot *slot, const Position &currShift
 
 // Return the amount to kern by.
 Position KernCollider::resolve(GR_MAYBE_UNUSED Segment *seg, GR_MAYBE_UNUSED Slot *slot,
-        int dir, float margin, GR_MAYBE_UNUSED json * const dbgout)
+        int dir, GR_MAYBE_UNUSED json * const dbgout)
 {
-    float resultNeeded = (1 - 2 * (dir & 1)) * (_mingap - margin);
+    float resultNeeded = (1 - 2 * (dir & 1)) * _mingap;
+    // float resultNeeded = (1 - 2 * (dir & 1)) * (_mingap - margin);
     float result = min(_limit.tr.x - _offsetPrev.x, max(resultNeeded, _limit.bl.x - _offsetPrev.x));
 
 #if !defined GRAPHITE2_NTRACING
@@ -998,7 +999,6 @@ Position KernCollider::resolve(GR_MAYBE_UNUSED Segment *seg, GR_MAYBE_UNUSED Slo
         *dbgout << json::object // slot
                 << "slot" << objectid(dslot(seg, _target))
 				<< "gid" << _target->gid()
-                << "margin" << _margin
                 << "limit" << _limit
                 << "miny" << _miny
                 << "maxy" << _maxy
@@ -1093,3 +1093,7 @@ float SlotCollision::getKern(int dir) const
     	return 0;
 }
 
+bool SlotCollision::ignore() const
+{
+	return ((flags() & SlotCollision::COLL_IGNORE) || (flags() & SlotCollision::COLL_ISSPACE));
+}
diff --git a/gfx/graphite2/src/Face.cpp b/gfx/graphite2/src/Face.cpp
index 90f200251f70..81b5ced8c184 100644
--- a/gfx/graphite2/src/Face.cpp
+++ b/gfx/graphite2/src/Face.cpp
@@ -190,9 +190,10 @@ bool Face::runGraphite(Segment *seg, const Silf *aSilf) const
 #if !defined GRAPHITE2_NTRACING
     if (dbgout)
 {
-        seg->positionSlots(0, 0, 0, aSilf->dir());
+        seg->positionSlots(0, 0, 0, seg->currdir());
         *dbgout             << json::item
                             << json::close // Close up the passes array
+                << "outputdir" << (seg->currdir() ? "rtl" : "ltr")
                 << "output" << json::array;
         for(Slot * s = seg->first(); s; s = s->next())
             *dbgout     << dslot(seg, s);
diff --git a/gfx/graphite2/src/GlyphFaceCache.cpp b/gfx/graphite2/src/GlyphFaceCache.cpp
deleted file mode 100644
index 9abb1aa9d060..000000000000
--- a/gfx/graphite2/src/GlyphFaceCache.cpp
+++ /dev/null
@@ -1,149 +0,0 @@
-/*  GRAPHITE2 LICENSING
-
-    Copyright 2010, SIL International
-    All rights reserved.
-
-    This library is free software; you can redistribute it and/or modify
-    it under the terms of the GNU Lesser General Public License as published
-    by the Free Software Foundation; either version 2.1 of License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Lesser General Public License for more details.
-
-    You should also have received a copy of the GNU Lesser General Public
-    License along with this library in the file named "LICENSE".
-    If not, write to the Free Software Foundation, 51 Franklin Street, 
-    Suite 500, Boston, MA 02110-1335, USA or visit their web page on the 
-    internet at http://www.fsf.org/licenses/lgpl.html.
-
-Alternatively, the contents of this file may be used under the terms of the
-Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
-License, as published by the Free Software Foundation, either version 2
-of the License or (at your option) any later version.
-*/
-#include "inc/GlyphFaceCache.h"
-#include "graphite2/Font.h"
-#include "inc/Face.h"     //for the tags
-#include "inc/Endian.h"
-
-using namespace graphite2;
-
-/*virtual*/ bool GlyphFaceCacheHeader::initialize(const Face & face, const bool dumb_font)    //return result indicates success. Do not use if failed.
-{
-    if ((m_pLoca = face.getTable(Tag::loca, &m_lLoca)) == NULL) return false;
-    if ((m_pHead = face.getTable(Tag::head)) == NULL) return false;
-    if ((m_pGlyf = face.getTable(Tag::glyf, &m_lGlyf)) == NULL) return false;
-    if ((m_pHmtx = face.getTable(Tag::hmtx, &m_lHmtx)) == NULL) return false;
-    if ((m_pHHea = face.getTable(Tag::hhea)) == NULL) return false;
-
-    const void* pMaxp = face.getTable(Tag::maxp);
-    if (pMaxp == NULL) return false;
-    m_nGlyphs = m_nGlyphsWithGraphics = (unsigned short)TtfUtil::GlyphCount(pMaxp);
-    if (TtfUtil::LocaLookup(m_nGlyphs-1, m_pLoca, m_lLoca, m_pHead) == size_t(-1))
-    	return false; // This will fail if m_nGlyphs is wildly out of range.
-
-    if (!dumb_font)
-    {
-		if ((m_pGlat = face.getTable(Tag::Glat, &m_lGlat)) == NULL) return false;
-		m_fGlat = be::peek<uint32>(m_pGlat);
-		size_t lGloc;
-		if ((m_pGloc = face.getTable(Tag::Gloc, &lGloc)) == NULL) return false;
-		if (lGloc < 6) return false;
-		int version = be::read<uint32>(m_pGloc);
-		if (version != 0x00010000) return false;
-
-		const uint16 locFlags = be::read<uint16>(m_pGloc);
-		m_numAttrs = be::read<uint16>(m_pGloc);
-		if (m_numAttrs > 0x1000) return false;                  // is this hard limit appropriate?
-
-		if (locFlags & 1)
-		{
-			m_locFlagsUse32Bit = true;
-			m_nGlyphsWithAttributes = (unsigned short)((lGloc - 12) / 4);
-		}
-		else
-		{
-			m_locFlagsUse32Bit = false;
-			m_nGlyphsWithAttributes = (unsigned short)((lGloc - 10) / 2);
-		}
-
-		if (m_nGlyphsWithAttributes > m_nGlyphs)
-	        m_nGlyphs = m_nGlyphsWithAttributes;
-    }
-
-    return true;
-}
-
-GlyphFaceCache* GlyphFaceCache::makeCache(const GlyphFaceCacheHeader& hdr)
-{
-    return new (hdr) GlyphFaceCache(hdr);
-}
-
-GlyphFaceCache::GlyphFaceCache(const GlyphFaceCacheHeader& hdr)
-:   GlyphFaceCacheHeader(hdr)
-{
-    unsigned int nGlyphs = numGlyphs();
-    
-    for (unsigned int i = 0; i < nGlyphs; i++)
-    {
-         *glyphPtrDirect(i) = NULL;
-    }
-}
-
-GlyphFaceCache::~GlyphFaceCache()
-{
-    unsigned int nGlyphs = numGlyphs();
-    int deltaPointers = (*glyphPtrDirect(nGlyphs-1u) - *glyphPtrDirect(0u));
-    if ((nGlyphs > 0u) && (deltaPointers == static_cast<int>(nGlyphs - 1)))
-    {
-        for (unsigned int i=0 ; i<nGlyphs; ++i)
-        {
-            GlyphFace *p = *glyphPtrDirect(i);
-            assert (p);
-            p->~GlyphFace();
-        }
-        free (*glyphPtrDirect(0));
-    }
-    else
-    {
-        for (unsigned int i=0 ; i<nGlyphs; ++i)
-        {
-            GlyphFace *p = *glyphPtrDirect(i);
-            if (p)
-            {
-                p->~GlyphFace();
-                free(p);
-            }
-        }
-    }
-}
-
-void GlyphFaceCache::loadAllGlyphs()
-{
-    unsigned int nGlyphs = numGlyphs();
-//    size_t sparse_size = 0;
-    GlyphFace * glyphs = gralloc<GlyphFace>(nGlyphs);
-    for (unsigned short glyphid = 0; glyphid < nGlyphs; glyphid++)
-    {
-        GlyphFace **p = glyphPtrDirect(glyphid);
-        *p = &(glyphs[glyphid]);
-        new(*p) GlyphFace(*this, glyphid);
-//        sparse_size += (*p)->m_attrs._sizeof();
-    }
-//    const size_t flat_size = nGlyphs*(sizeof(uint16*) + sizeof(uint16)*numAttrs());
-//    assert(sparse_size <= flat_size);
-}
-
-/*virtual*/ const GlyphFace *GlyphFaceCache::glyph(unsigned short glyphid) const      //result may be changed by subsequent call with a different glyphid
-{ 
-    GlyphFace **p = glyphPtrDirect(glyphid);
-    if (*p)
-        return *p;
-
-    *p = (GlyphFace*)malloc(sizeof(GlyphFace));
-    new(*p) GlyphFace(*this, glyphid);
-    return *p;
-}
diff --git a/gfx/graphite2/src/Intervals.cpp b/gfx/graphite2/src/Intervals.cpp
index 1e34e5987154..9b1da5a1b995 100644
--- a/gfx/graphite2/src/Intervals.cpp
+++ b/gfx/graphite2/src/Intervals.cpp
@@ -59,7 +59,9 @@ Zones::Exclusion & Zones::Exclusion::operator += (Exclusion const & rhs) {
 inline
 uint8 Zones::Exclusion::outcode(float val) const {
     float p = val;
-    return ((p >= xm) << 1) | (p < x);
+    //float d = std::numeric_limits<float>::epsilon();
+    float d = 0.;
+    return ((p - xm >= d) << 1) | (x - p > d);
 }
 
 void Zones::exclude_with_margins(float xmin, float xmax, int axis) {
@@ -74,6 +76,9 @@ namespace
 inline
 bool separated(float a, float b) {
     return a != b;
+    //int exp;
+    //float res = frexpf(fabs(a - b), &exp);
+    //return (*(unsigned int *)(&res) > 4);
     //return std::fabs(a-b) > std::numeric_limits<float>::epsilon(); // std::epsilon may not work. but 0.5 fails exising 64 bit tests
     //return std::fabs(a-b) > 0.5f;
 }
diff --git a/gfx/graphite2/src/MozGrMalloc.h b/gfx/graphite2/src/MozGrMalloc.h
old mode 100644
new mode 100755
diff --git a/gfx/graphite2/src/Pass.cpp b/gfx/graphite2/src/Pass.cpp
index 1c9c73c1e857..69ad700c86a2 100644
--- a/gfx/graphite2/src/Pass.cpp
+++ b/gfx/graphite2/src/Pass.cpp
@@ -523,7 +523,7 @@ void Pass::findNDoRule(Slot * & slot, Machine &m, FiniteStateMachine & fsm) cons
                 if (r != re)
                 {
                     const int adv = doAction(r->rule->action, slot, m);
-                    dumpRuleEventOutput(fsm, m, *r->rule, slot);
+                    dumpRuleEventOutput(fsm, *r->rule, slot);
                     if (r->rule->action->deletes()) fsm.slots.collectGarbage(slot);
                     adjustSlot(adv, slot, fsm.slots);
                     *fsm.dbgout << "cursor" << objectid(dslot(&fsm.slots.segment, slot))
@@ -579,7 +579,7 @@ void Pass::dumpRuleEventConsidered(const FiniteStateMachine & fsm, const RuleEnt
 }
 
 
-void Pass::dumpRuleEventOutput(const FiniteStateMachine & fsm, Machine & m, const Rule & r, Slot * const last_slot) const
+void Pass::dumpRuleEventOutput(const FiniteStateMachine & fsm, const Rule & r, Slot * const last_slot) const
 {
     *fsm.dbgout     << json::item << json::flat << json::object
                         << "id"     << &r - m_rules
@@ -597,7 +597,7 @@ void Pass::dumpRuleEventOutput(const FiniteStateMachine & fsm, Machine & m, cons
                     << json::close // close "input"
                     << "slots"  << json::array;
     const Position rsb_prepos = last_slot ? last_slot->origin() : fsm.slots.segment.advance();
-    fsm.slots.segment.positionSlots(0, 0, 0, m.slotMap().dir());
+    fsm.slots.segment.positionSlots(0, 0, 0, fsm.slots.segment.currdir());
 
     for(Slot * slot = output_slot(fsm.slots, 0); slot != last_slot; slot = slot->next())
         *fsm.dbgout     << dslot(&fsm.slots.segment, slot);
@@ -879,8 +879,11 @@ bool Pass::collisionKern(Segment *seg, int dir, json * const dbgout) const
         const SlotCollision * c = seg->collisionInfo(s);
         const Rect &bbox = seg->theGlyphBBoxTemporary(s->gid());
         float y = s->origin().y + c->shift().y;
-        ymax = max(y + bbox.tr.y, ymax);
-        ymin = min(y + bbox.bl.y, ymin);
+        if (!(c->flags() & SlotCollision::COLL_ISSPACE))
+        {
+            ymax = max(y + bbox.tr.y, ymax);
+            ymin = min(y + bbox.bl.y, ymin);
+        }
         if (start && (c->flags() & (SlotCollision::COLL_KERN | SlotCollision::COLL_FIX))
                         == (SlotCollision::COLL_KERN | SlotCollision::COLL_FIX))
             resolveKern(seg, s, start, dir, ymin, ymax, dbgout);
@@ -962,8 +965,8 @@ bool Pass::resolveCollisions(Segment *seg, Slot *slotFix, Slot *start,
     {
         SlotCollision *cNbor = seg->collisionInfo(nbor);
         bool sameCluster = nbor->isChildOf(base);
-        if (nbor != slotFix         // don't process if this is the slot of interest
-                      && !(cNbor->flags() & SlotCollision::COLL_IGNORE)    // don't process if ignoring
+        if (nbor != slotFix         						// don't process if this is the slot of interest
+                      && !(cNbor->ignore())    				// don't process if ignoring
                       && (nbor == base || sameCluster       // process if in the same cluster as slotFix
                             || !inKernCluster(seg, nbor)    // or this cluster is not to be kerned
                             || (rtl ^ ignoreForKern))       // or it comes before(ltr) or after(rtl)
@@ -1052,7 +1055,7 @@ float Pass::resolveKern(Segment *seg, Slot *slotFix, GR_MAYBE_UNUSED Slot *start
             return 0.;
         const Rect &bb = seg->theGlyphBBoxTemporary(nbor->gid());
         SlotCollision *cNbor = seg->collisionInfo(nbor);
-        if (bb.bl.y == 0.f && bb.tr.y == 0.f)
+        if ((bb.bl.y == 0.f && bb.tr.y == 0.f) || (cNbor->flags() & SlotCollision::COLL_ISSPACE))
         {
             if (m_kernColls == InWord)
                 break;
@@ -1066,7 +1069,7 @@ float Pass::resolveKern(Segment *seg, Slot *slotFix, GR_MAYBE_UNUSED Slot *start
             float y = nbor->origin().y + cNbor->shift().y;
             ymax = max(y + bb.tr.y, ymax);
             ymin = min(y + bb.bl.y, ymin);
-            if (nbor != slotFix && !(cNbor->flags() & SlotCollision::COLL_IGNORE))
+            if (nbor != slotFix && !cNbor->ignore())
             {
                 seenEnd = true;
                 if (!isInit)
@@ -1089,7 +1092,7 @@ float Pass::resolveKern(Segment *seg, Slot *slotFix, GR_MAYBE_UNUSED Slot *start
     }
     if (collides)
     {
-        Position mv = coll.resolve(seg, slotFix, dir, cFix->margin(), dbgout);
+        Position mv = coll.resolve(seg, slotFix, dir, dbgout);
         coll.shift(mv, dir);
         Position delta = slotFix->advancePos() + mv - cFix->shift();
         slotFix->advance(delta);
diff --git a/gfx/graphite2/src/Rule.cpp b/gfx/graphite2/src/Rule.cpp
deleted file mode 100644
index 34c8ae1691fd..000000000000
--- a/gfx/graphite2/src/Rule.cpp
+++ /dev/null
@@ -1,31 +0,0 @@
-/*  GRAPHITE2 LICENSING
-
-    Copyright 2011, SIL International
-    All rights reserved.
-
-    This library is free software; you can redistribute it and/or modify
-    it under the terms of the GNU Lesser General Public License as published
-    by the Free Software Foundation; either version 2.1 of License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Lesser General Public License for more details.
-
-    You should also have received a copy of the GNU Lesser General Public
-    License along with this library in the file named "LICENSE".
-    If not, write to the Free Software Foundation, 51 Franklin Street, 
-    Suite 500, Boston, MA 02110-1335, USA or visit their web page on the 
-    internet at http://www.fsf.org/licenses/lgpl.html.
-
-Alternatively, the contents of this file may be used under the terms of the
-Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
-License, as published by the Free Software Foundation, either version 2
-of the License or (at your option) any later version.
-*/
-
-#include "inc/Rule.h"
-#include "inc/Segment.h"
-
-using namespace graphite2;
diff --git a/gfx/graphite2/src/Segment.cpp b/gfx/graphite2/src/Segment.cpp
index 966f75784dd3..3020bfd36d08 100644
--- a/gfx/graphite2/src/Segment.cpp
+++ b/gfx/graphite2/src/Segment.cpp
@@ -412,8 +412,9 @@ Position Segment::positionSlots(const Font *font, Slot * iStart, Slot * iEnd, bo
     Position currpos(0., 0.);
     float clusterMin = 0.;
     Rect bbox;
+    bool reorder = (currdir() != isRtl);
 
-    if (currdir() != isRtl)
+    if (reorder)
     {
         Slot *temp;
         reverseSlots();
@@ -443,6 +444,8 @@ Position Segment::positionSlots(const Font *font, Slot * iStart, Slot * iEnd, bo
                 currpos = s->finalise(this, font, currpos, bbox, 0, clusterMin = currpos.x, isRtl, isFinal);
         }
     }
+    if (reorder)
+        reverseSlots();
     return currpos;
 }
 
diff --git a/gfx/graphite2/src/Silf.cpp b/gfx/graphite2/src/Silf.cpp
index 02876881e6f5..72a22cd46866 100644
--- a/gfx/graphite2/src/Silf.cpp
+++ b/gfx/graphite2/src/Silf.cpp
@@ -384,9 +384,12 @@ bool Silf::runGraphite(Segment *seg, uint8 firstPass, uint8 lastPass, int dobidi
             if (dbgout)
             {
                 *dbgout << json::item << json::object
+//							<< "pindex" << i   // for debugging
                             << "id"     << -1
+                            << "slotsdir" << (seg->currdir() ? "rtl" : "ltr")
+                            << "passdir" << (m_dir & 1 ? "rtl" : "ltr")
                             << "slots"  << json::array;
-                seg->positionSlots(0, 0, 0, m_dir);
+                seg->positionSlots(0, 0, 0, seg->currdir());
                 for(Slot * s = seg->first(); s; s = s->next())
                     *dbgout     << dslot(seg, s);
                 *dbgout         << json::close
@@ -408,9 +411,12 @@ bool Silf::runGraphite(Segment *seg, uint8 firstPass, uint8 lastPass, int dobidi
         if (dbgout)
         {
             *dbgout << json::item << json::object
+//						<< "pindex" << i   // for debugging
                         << "id"     << i+1
+                        << "slotsdir" << (seg->currdir() ? "rtl" : "ltr")
+                        << "passdir" << ((m_dir & 1) ^ m_passes[i].reverseDir() ? "rtl" : "ltr")
                         << "slots"  << json::array;
-            seg->positionSlots(0, 0, 0, m_dir);
+            seg->positionSlots(0, 0, 0, seg->currdir());
             for(Slot * s = seg->first(); s; s = s->next())
                 *dbgout     << dslot(seg, s);
             *dbgout         << json::close;
diff --git a/gfx/graphite2/src/XmlTraceLog.cpp b/gfx/graphite2/src/XmlTraceLog.cpp
deleted file mode 100644
index f34d15018f3f..000000000000
--- a/gfx/graphite2/src/XmlTraceLog.cpp
+++ /dev/null
@@ -1,219 +0,0 @@
-/*  GRAPHITE2 LICENSING
-
-    Copyright 2010, SIL International
-    All rights reserved.
-
-    This library is free software; you can redistribute it and/or modify
-    it under the terms of the GNU Lesser General Public License as published
-    by the Free Software Foundation; either version 2.1 of License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Lesser General Public License for more details.
-
-    You should also have received a copy of the GNU Lesser General Public
-    License along with this library in the file named "LICENSE".
-    If not, write to the Free Software Foundation, 51 Franklin Street, 
-    Suite 500, Boston, MA 02110-1335, USA or visit their web page on the 
-    internet at http://www.fsf.org/licenses/lgpl.html.
-
-Alternatively, the contents of this file may be used under the terms of the
-Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
-License, as published by the Free Software Foundation, either version 2
-of the License or (at your option) any later version.
-*/
-
-#include <cstring>
-#include <cstdarg>
-#include "Main.h"
-#include "XmlTraceLog.h"
-
-
-using namespace graphite2;
-
-#ifndef DISABLE_TRACING
-
-/*static*/ XmlTraceLog XmlTraceLog::sm_NullLog(NULL, NULL, GRLOG_NONE);
-XmlTraceLog * XmlTraceLog::sLog = &sm_NullLog;
-
-XmlTraceLog::XmlTraceLog(FILE * file, const char * ns, GrLogMask logMask)
-                         : m_file(file), m_depth(0), m_mask(logMask)
-{
-    if (!m_file) return;
-    int deep = 0;
-#ifdef ENABLE_DEEP_TRACING
-    deep = 1;
-#endif
-    fprintf(m_file, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<%s xmlns=\"%s\" mask=\"%x\" deep=\"%d\">",
-            xmlTraceLogElements[ElementTopLevel].mName, ns, logMask, deep);
-    m_elementStack[m_depth++] = ElementTopLevel;
-    m_elementEmpty = true;
-    m_inElement = false;
-    m_lastNodeText = false;
-}
-
-XmlTraceLog::~XmlTraceLog()
-{
-    if (m_file && m_file != stdout && m_file != stderr)
-    {
-        assert(m_depth == 1);
-        while (m_depth > 0)
-        {
-            closeElement(m_elementStack[m_depth-1]);
-        }
-        fclose(m_file);
-        m_file = NULL;
-    }
-}
-
-void XmlTraceLog::addSingleElement(XmlTraceLogElement eId, const int value)
-{
-    if (!m_file) return;
-    if (m_inElement)
-    {
-        if (xmlTraceLogElements[m_elementStack[m_depth-1]].mFlags & m_mask)
-            fprintf(m_file, ">");
-    }
-    if (xmlTraceLogElements[eId].mFlags & m_mask)
-    {
-        if (!m_lastNodeText)
-        {
-            fprintf(m_file, "\n");
-            for (size_t i = 0; i < m_depth; i++)
-            {
-                fprintf(m_file, " ");
-            }
-        }
-        fprintf(m_file, "<%s val=\"%d\"/>", xmlTraceLogElements[eId].mName, value);
-    }
-    m_inElement = false;
-    m_lastNodeText = false;
-}
-    
-void XmlTraceLog::writeElementArray(XmlTraceLogElement eId, XmlTraceLogAttribute aId, int16 values [], size_t length)
-{
-    if (!m_file) return;
-    if (xmlTraceLogElements[eId].mFlags & m_mask)
-    {
-        if(m_inElement && xmlTraceLogElements[m_elementStack[m_depth-1]].mFlags & m_mask)
-        {
-            fprintf(m_file, ">");
-            m_inElement = false;
-        }
-        // line break after 5 columns
-        for (size_t i = 0; i < length; i++)
-        {
-            if (i % 5 == 0)
-            {
-                fprintf(m_file, "\n");
-                for (size_t j = 0; j < m_depth; j++)
-                {
-                    fprintf(m_file, " ");
-                }
-            }
-            fprintf(m_file, "<%s index=\"%d\" %s=\"%d\"/>", xmlTraceLogElements[eId].mName, int(i),
-                xmlTraceLogAttributes[aId], (int)values[i]);
-        }
-    }
-}
-
-void XmlTraceLog::writeText(const char * utf8)
-{
-    if (!m_file) return;
-    if (m_inElement)
-    {
-        if (xmlTraceLogElements[m_elementStack[m_depth-1]].mFlags & m_mask)
-        {
-            fprintf(m_file, ">");
-        }
-        m_inElement = false;
-    }
-    if (xmlTraceLogElements[m_elementStack[m_depth-1]].mFlags & m_mask)
-    {
-        escapeIfNeeded(utf8);
-    }
-    m_lastNodeText = true;
-}
-
-void XmlTraceLog::writeUnicode(const uint32 code)
-{
-    if (!m_file) return;
-    if (m_inElement)
-    {
-        if (xmlTraceLogElements[m_elementStack[m_depth-1]].mFlags & m_mask)
-        {
-            fprintf(m_file, ">");
-        }
-        m_inElement = false;
-    }
-    if (xmlTraceLogElements[m_elementStack[m_depth-1]].mFlags & m_mask)
-    {
-        fprintf(m_file, "&#x%02x;", code);
-    }
-    m_lastNodeText = true;
-}
-
-void XmlTraceLog::escapeIfNeeded(const char * data)
-{
-    size_t length = strlen(data);
-    for (size_t i = 0; i < length; i++)
-    {
-        switch (data[i])
-        {
-            case '<':
-                fprintf(m_file, "&lt;");
-                break;
-            case '>':
-                fprintf(m_file, "&gt;");
-                break;
-            case '&':
-                fprintf(m_file, "&amp;");
-                break;
-            case '"':
-                fprintf(m_file, "&#34;");
-                break;
-            default:
-                fprintf(m_file, "%c", data[i]);
-        }
-    }
-}
-
-static const int MAX_MSG_LEN = 1024;
-
-void XmlTraceLog::error(const char * msg, ...)
-{
-    if (!m_file) return;
-    openElement(ElementError);
-    va_list args;
-    va_start(args, msg);
-    char buffer[MAX_MSG_LEN];
-#ifndef NDEBUG
-    int len =
-#endif
-        vsnprintf(buffer, MAX_MSG_LEN, msg, args);
-    assert(len + 1 < MAX_MSG_LEN);
-    writeText(buffer);
-    va_end(args);
-    closeElement(ElementError);
-}
-
-void XmlTraceLog::warning(const char * msg, ...)
-{
-    if (!m_file) return;
-    openElement(ElementWarning);
-    va_list args;
-    va_start(args, msg);
-    char buffer[MAX_MSG_LEN];
-#ifndef NDEBUG
-    int len =
-#endif
-        vsnprintf(buffer, MAX_MSG_LEN, msg, args);
-    assert(len + 1 < MAX_MSG_LEN);
-    writeText(buffer);
-    va_end(args);
-    closeElement(ElementWarning);
-}
-
-#endif		//!DISABLE_TRACING
diff --git a/gfx/graphite2/src/XmlTraceLogTags.cpp b/gfx/graphite2/src/XmlTraceLogTags.cpp
deleted file mode 100644
index b6ec970ac233..000000000000
--- a/gfx/graphite2/src/XmlTraceLogTags.cpp
+++ /dev/null
@@ -1,169 +0,0 @@
-/*  GRAPHITE2 LICENSING
-
-    Copyright 2010, SIL International
-    All rights reserved.
-
-    This library is free software; you can redistribute it and/or modify
-    it under the terms of the GNU Lesser General Public License as published
-    by the Free Software Foundation; either version 2.1 of License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Lesser General Public License for more details.
-
-    You should also have received a copy of the GNU Lesser General Public
-    License along with this library in the file named "LICENSE".
-    If not, write to the Free Software Foundation, 51 Franklin Street, 
-    Suite 500, Boston, MA 02110-1335, USA or visit their web page on the 
-    internet at http://www.fsf.org/licenses/lgpl.html.
-
-Alternatively, the contents of this file may be used under the terms of the
-Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
-License, as published by the Free Software Foundation, either version 2
-of the License or (at your option) any later version.
-*/
-#include "Main.h"
-#include "XmlTraceLogTags.h"
-
-
-using namespace graphite2;
-
-#ifndef DISABLE_TRACING
-
-
-// start this at same line number as in XmlTraceLogTags.h
-const XmlTraceLogTag graphite2::xmlTraceLogElements[NumElements] = {
-    XmlTraceLogTag("Graphite2Log", GRLOG_ALL),
-    XmlTraceLogTag("Face", GRLOG_FACE | GRLOG_PASS),
-    XmlTraceLogTag("Glyphs", GRLOG_FACE),
-    XmlTraceLogTag("GlyphFace", GRLOG_FACE),
-    XmlTraceLogTag("Attr", GRLOG_FACE),
-    XmlTraceLogTag("Silf", GRLOG_FACE | GRLOG_PASS),
-    XmlTraceLogTag("SilfSub", GRLOG_FACE | GRLOG_PASS),
-    XmlTraceLogTag("Pass", GRLOG_FACE | GRLOG_PASS),
-    XmlTraceLogTag("Pseudo", GRLOG_FACE | GRLOG_PASS),
-    XmlTraceLogTag("ClassMap", GRLOG_FACE | GRLOG_PASS),
-    XmlTraceLogTag("LookupClass", GRLOG_FACE | GRLOG_PASS),
-    XmlTraceLogTag("Lookup", GRLOG_FACE | GRLOG_PASS),
-    XmlTraceLogTag("Range", GRLOG_PASS),
-    XmlTraceLogTag("RuleMap", GRLOG_PASS),
-    XmlTraceLogTag("Rule", GRLOG_PASS),
-    XmlTraceLogTag("StartState", GRLOG_PASS),
-    XmlTraceLogTag("StateTransitions", GRLOG_PASS),
-    XmlTraceLogTag("TR", GRLOG_PASS),
-    XmlTraceLogTag("TD", GRLOG_PASS),
-    XmlTraceLogTag("Constraint", GRLOG_PASS),
-    XmlTraceLogTag("Constraints", GRLOG_PASS),
-    XmlTraceLogTag("Actions", GRLOG_PASS),
-    XmlTraceLogTag("Action", GRLOG_PASS),
-    XmlTraceLogTag("Features", GRLOG_PASS),
-    XmlTraceLogTag("Feature", GRLOG_PASS),
-    XmlTraceLogTag("FeatureSetting", GRLOG_PASS),
-    XmlTraceLogTag("Segment", GRLOG_SEGMENT),
-    XmlTraceLogTag("Slot", GRLOG_SEGMENT),
-    XmlTraceLogTag("Text", GRLOG_SEGMENT),
-    XmlTraceLogTag("OpCode", GRLOG_OPCODE),
-    XmlTraceLogTag("TestRule", GRLOG_OPCODE),
-    XmlTraceLogTag("DoRule", GRLOG_OPCODE),
-    XmlTraceLogTag("RunPass", GRLOG_OPCODE),
-    XmlTraceLogTag("Params", GRLOG_OPCODE),
-    XmlTraceLogTag("Push", GRLOG_OPCODE),
-    XmlTraceLogTag("SubSeg", GRLOG_SEGMENT),
-    XmlTraceLogTag("SegCache", GRLOG_CACHE),
-    XmlTraceLogTag("SegCacheEntry", GRLOG_CACHE),
-    XmlTraceLogTag("Glyph", GRLOG_CACHE),
-    XmlTraceLogTag("PassResult", GRLOG_OPCODE),
-
-    XmlTraceLogTag("Error", GRLOG_ALL),
-    XmlTraceLogTag("Warning", GRLOG_ALL)
-    // Nothing corresponds to NumElements
-};
-
-
-
-// start this at same line number as in XmlTraceLogTags.h
-const char * graphite2::xmlTraceLogAttributes[NumAttributes] = {
-    "index",
-    "version",
-    "major",
-    "minor",
-    "num",
-    "glyphId",
-    "advance",
-    "advanceX",
-    "advanceY",
-    "attrId",
-    "attrVal",
-    "compilerMajor",
-    "compilerMinor",
-    "numPasses",//AttrNumPasses,
-    "subPass",//AttrSubPass,
-    "posPass",//AttrPosPass,
-    "justPass",//AttrJustPass,
-    "bidiPass",//AttrBidiPass,
-    "preContext",//AttrPreContext,
-    "postContext",//AttrPostContext,
-    "pseudoGlyph",//AttrPseudoGlyph,
-    "breakWeight",//AttrBreakWeight,
-    "directionality",//AttrDirectionality,
-    "numJustLevels",//AttrNumJustLevels,
-    "numLigCompAttr",//AttrLigComp,
-    "numUserDefinedAttr",//AttrUserDefn,
-    "maxNumLigComp",//AttrNumLigComp,
-    "numCriticalFeatures",//AttrNumCritFeatures,
-    "numScripts",//AttrNumScripts
-    "lineBreakglyph",//,AttrLBGlyph,
-    "numPseudo",
-    "numClasses",
-    "numLinear",
-    "passId",//AttrPassId,
-    "flags",//AttrFlags,
-    "maxRuleLoop",//AttrMaxRuleLoop,
-    "maxRuleContext",//AttrMaxRuleContext,
-    "maxBackup",//AttrMaxBackup,
-    "numRules",//AttrNumRules,
-    "numRows",//AttrNumRows,
-    "numTransitionStates",//AttrNumTransition,
-    "numSuccessStates",//AttrNumSuccess,
-    "numColumns",//AttrNumColumns,
-    "numRanges",//AttrNumRanges,
-    "minPrecontext",//AttrMinPrecontext,
-    "maxPrecontext",//AttrMaxPrecontext,
-    "firstId",
-    "lastId",
-    "colId",
-    "successId",
-    "ruleId",
-    "contextLength",
-    "state",
-    "value",
-    "sortKey",
-    "precontext",
-    "action",
-    "actionCode",
-    "arg1",
-    "arg2",
-    "arg3",
-    "arg4",
-    "arg5",
-    "arg6",
-    "arg7",
-    "arg8",
-    "label",
-    "length",
-    "x",
-    "y",
-    "before",
-    "after",
-    "encoding",
-    "name",
-    "result",
-    "default",
-    "accessCount",
-    "lastAccess",
-    "misses"
-};
-
-#endif
diff --git a/gfx/graphite2/src/inc/Bidi.h b/gfx/graphite2/src/inc/Bidi.h
deleted file mode 100644
index 9593c7e149a8..000000000000
--- a/gfx/graphite2/src/inc/Bidi.h
+++ /dev/null
@@ -1,126 +0,0 @@
-/*  GRAPHITE2 LICENSING
-
-    Copyright 2013, SIL International
-    All rights reserved.
-
-    This library is free software; you can redistribute it and/or modify
-    it under the terms of the GNU Lesser General Public License as published
-    by the Free Software Foundation; either version 2.1 of License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Lesser General Public License for more details.
-
-    You should also have received a copy of the GNU Lesser General Public
-    License along with this library in the file named "LICENSE".
-    If not, write to the Free Software Foundation, 51 Franklin Street,
-    Suite 500, Boston, MA 02110-1335, USA or visit their web page on the
-    internet at http://www.fsf.org/licenses/lgpl.html.
-
-Alternatively, the contents of this file may be used under the terms of the
-Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
-License, as published by the Free Software Foundation, either version 2
-of the License or (at your option) any later version.
-*/
-#pragma once
-
-namespace graphite2
-{
-
-class BracketPair
-{
-public:
-    BracketPair(uint16 g, Slot *s, uint8 b, BracketPair *p, BracketPair *l) : _open(s), _close(0), _parent(p), _next(0), _prev(l), _gid(g), _mask(0), _before(b) {};
-    uint16 gid() const { return _gid; }
-    Slot *open() const { return _open; }
-    Slot *close() const { return _close; }
-    uint8 mask() const { return _mask; }
-    int8 before() const { return _before; }
-    BracketPair *parent() const { return _parent; }
-    void close(Slot *s) { _close = s; }
-    BracketPair *next() const { return _next; }
-    BracketPair *prev() const { return _prev; }
-    void next(BracketPair *n) { _next = n; }
-    void orin(uint8 m) { _mask |= m; }
-private:
-    Slot        *   _open;          // Slot of opening paren
-    Slot        *   _close;         // Slot of closing paren
-    BracketPair *   _parent;        // pair this pair is in or NULL
-    BracketPair *   _next;          // next pair along the string
-    BracketPair *   _prev;          // pair that closed last before we opened
-    uint16          _gid;           // gid of closing paren
-    uint8           _mask;          // bitmap (2 bits) of directions within the pair
-    int8            _before;        // most recent strong type (L, R, OPP, CPP)
-};
-
-class BracketPairStack
-{
-public:
-    BracketPairStack(int s) : _stack(grzeroalloc<BracketPair>(s)), _ip(_stack - 1), _top(0), _last(0), _lastclose(0), _size(s) {}
-    ~BracketPairStack() { free(_stack); }
-
-public:
-    BracketPair *scan(uint16 gid);
-    void close(BracketPair *tos, Slot *s);
-    BracketPair *push(uint16 gid, Slot *pos, uint8 before, int prevopen);
-    void orin(uint8 mask);
-    void clear() { _ip = _stack - 1; _top = 0; _last = 0; _lastclose = 0; }
-    int size() const { return _size; }
-    BracketPair *start() const { return _stack; }
-
-    CLASS_NEW_DELETE
-
-private:
-
-    BracketPair *_stack;        // start of storage
-    BracketPair *_ip;           // where to add the next pair
-    BracketPair *_top;          // current parent
-    BracketPair *_last;         // end of next() chain
-    BracketPair *_lastclose;    // last pair to close
-    int          _size;         // capacity
-};
-
-inline BracketPair *BracketPairStack::scan(uint16 gid)
-{
-    BracketPair *res = _top;
-    while (res >= _stack)
-    {
-        if (res->gid() == gid)
-            return res;
-        res = res->parent();
-    }
-    return 0;
-}
-
-inline void BracketPairStack::close(BracketPair *tos, Slot *s) 
-{
-    for ( ; _last && _last != tos && !_last->close(); _last = _last->parent())
-    { }
-    tos->close(s);
-    _last->next(NULL);
-    _lastclose = tos;
-    _top = tos->parent();
-}
-
-inline BracketPair *BracketPairStack::push(uint16 gid, Slot *pos, uint8 before, int prevopen)
-{
-    if (++_ip - _stack < _size && _stack)
-    {
-        ::new (_ip) BracketPair(gid, pos, before, _top, prevopen ? _last : _lastclose);
-        if (_last) _last->next(_ip);
-        _last = _ip;
-    }
-    _top = _ip;
-    return _ip;
-}
-
-inline void BracketPairStack::orin(uint8 mask)
-{
-    BracketPair *t = _top;
-    for ( ; t; t = t->parent())
-        t->orin(mask);
-}
-
-}
diff --git a/gfx/graphite2/src/inc/Collider.h b/gfx/graphite2/src/inc/Collider.h
index bcbf3a224903..84008128ab45 100644
--- a/gfx/graphite2/src/inc/Collider.h
+++ b/gfx/graphite2/src/inc/Collider.h
@@ -54,7 +54,8 @@ public:
         COLL_KERN = 16,     // collisions with this glyph are fixed by adding kerning space after it
         COLL_ISCOL = 32,    // this glyph has a collision
         COLL_KNOWN = 64,    // we've figured out what's happening with this glyph
-        COLL_TEMPLOCK = 128,    // Lock glyphs that have been given priority positioning
+        COLL_ISSPACE = 128,		// treat this glyph as a space with regard to kerning
+        COLL_TEMPLOCK = 256,    // Lock glyphs that have been given priority positioning
         ////COLL_JUMPABLE = 128,    // moving glyphs may jump this stationary glyph in any direction - DELETE
         ////COLL_OVERLAP = 256,    // use maxoverlap to restrict - DELETE
     };
@@ -93,6 +94,7 @@ public:
     SLOTCOLSETUINTPROP(seqValignWt, setSeqValignWt)
 
     float getKern(int dir) const;
+    bool ignore() const;
     
 private:
     Rect        _limit;
@@ -191,7 +193,7 @@ public:
             const Position &currShift, const Position &offsetPrev, int dir,
             float ymin, float ymax, json * const dbgout);
     bool mergeSlot(Segment *seg, Slot *slot, const Position &currShift, float currSpace, int dir, json * const dbgout);
-    Position resolve(Segment *seg, Slot *slot, int dir, float margin, json * const dbgout);
+    Position resolve(Segment *seg, Slot *slot, int dir, json * const dbgout);
     void shift(const Position &mv, int dir);
 
     CLASS_NEW_DELETE;
diff --git a/gfx/graphite2/src/inc/GlyphFaceCache.h b/gfx/graphite2/src/inc/GlyphFaceCache.h
deleted file mode 100644
index 4afdfbe017fb..000000000000
--- a/gfx/graphite2/src/inc/GlyphFaceCache.h
+++ /dev/null
@@ -1,103 +0,0 @@
-/*  GRAPHITE2 LICENSING
-
-    Copyright 2010, SIL International
-    All rights reserved.
-
-    This library is free software; you can redistribute it and/or modify
-    it under the terms of the GNU Lesser General Public License as published
-    by the Free Software Foundation; either version 2.1 of License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Lesser General Public License for more details.
-
-    You should also have received a copy of the GNU Lesser General Public
-    License along with this library in the file named "LICENSE".
-    If not, write to the Free Software Foundation, 51 Franklin Street, 
-    Suite 500, Boston, MA 02110-1335, USA or visit their web page on the 
-    internet at http://www.fsf.org/licenses/lgpl.html.
-
-Alternatively, the contents of this file may be used under the terms of the
-Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
-License, as published by the Free Software Foundation, either version 2
-of the License or (at your option) any later version.
-*/
-#pragma once
-
-#include "inc/GlyphFace.h"
-#include "graphite2/Font.h"
-
-namespace graphite2 {
-
-class Segment;
-class Face;
-class FeatureVal;
-
-
-class GlyphFaceCacheHeader
-{
-public:
-    bool initialize(const Face & face, const bool dumb_font);    //return result indicates success. Do not use if failed.
-    unsigned short numGlyphs() const { return m_nGlyphs; }
-    unsigned short numAttrs() const { return m_numAttrs; }
-
-private:
-friend class Face;
-friend class GlyphFace;
-    const byte* m_pHead,
-    		  * m_pHHea,
-    		  * m_pHmtx,
-    		  * m_pGlat,
-    		  * m_pGloc,
-    		  * m_pGlyf,
-    		  * m_pLoca;
-    size_t		m_lHmtx,
-    			m_lGlat,
-    			m_lGlyf,
-    			m_lLoca;
-
-    uint32			m_fGlat;
-    unsigned short 	m_numAttrs,					// number of glyph attributes per glyph
-    				m_nGlyphsWithGraphics,		//i.e. boundary box and advance
-    				m_nGlyphsWithAttributes,
-    				m_nGlyphs;					// number of glyphs in the font. Max of the above 2.
-    bool 			m_locFlagsUse32Bit;
-};
-
-class GlyphFaceCache : public GlyphFaceCacheHeader
-{
-public:
-    static GlyphFaceCache* makeCache(const GlyphFaceCacheHeader& hdr /*, EGlyphCacheStrategy requested */);
-
-    GlyphFaceCache(const GlyphFaceCacheHeader& hdr);
-    ~GlyphFaceCache();
-
-    const GlyphFace *glyphSafe(unsigned short glyphid) const { return glyphid<numGlyphs()?glyph(glyphid):NULL; }
-    uint16 glyphAttr(uint16 gid, uint8 gattr) const { if (gattr>=numAttrs()) return 0; const GlyphFace*p=glyphSafe(gid); return p?p->getAttr(gattr):0; }
-
-    void * operator new (size_t s, const GlyphFaceCacheHeader& hdr)
-    {
-        return malloc(s + sizeof(GlyphFace*)*hdr.numGlyphs());
-    }
-    // delete in case an exception is thrown in constructor
-    void operator delete(void* p, const GlyphFaceCacheHeader& ) throw()
-    {
-        free(p);
-    }
-
-    const GlyphFace *glyph(unsigned short glyphid) const;      //result may be changed by subsequent call with a different glyphid
-    void loadAllGlyphs();
-
-    CLASS_NEW_DELETE
-    
-private:
-    GlyphFace **glyphPtrDirect(unsigned short glyphid) const { return (GlyphFace **)((const char*)(this)+sizeof(GlyphFaceCache)+sizeof(GlyphFace*)*glyphid);}
-
-private:      //defensive
-    GlyphFaceCache(const GlyphFaceCache&);
-    GlyphFaceCache& operator=(const GlyphFaceCache&);
-};
-
-} // namespace graphite2
diff --git a/gfx/graphite2/src/inc/Pass.h b/gfx/graphite2/src/inc/Pass.h
index 82da2caf15e4..074d501d95b5 100644
--- a/gfx/graphite2/src/inc/Pass.h
+++ b/gfx/graphite2/src/inc/Pass.h
@@ -74,7 +74,7 @@ private:
     uint16  glyphToCol(const uint16 gid) const;
     bool    runFSM(FiniteStateMachine & fsm, Slot * slot) const;
     void    dumpRuleEventConsidered(const FiniteStateMachine & fsm, const RuleEntry & re) const;
-    void    dumpRuleEventOutput(const FiniteStateMachine & fsm, vm::Machine & m, const Rule & r, Slot * os) const;
+    void    dumpRuleEventOutput(const FiniteStateMachine & fsm, const Rule & r, Slot * os) const;
     void    adjustSlot(int delta, Slot * & slot_out, SlotMap &) const;
     bool    collisionShift(Segment *seg, int dir, json * const dbgout) const;
     bool    collisionKern(Segment *seg, int dir, json * const dbgout) const;
diff --git a/gfx/graphite2/src/inc/Shrinker.h b/gfx/graphite2/src/inc/Shrinker.h
deleted file mode 100644
index e4db2f135a6a..000000000000
--- a/gfx/graphite2/src/inc/Shrinker.h
+++ /dev/null
@@ -1,119 +0,0 @@
-/*  Copyright (c) 2012, Siyuan Fu <fusiyuan2010@gmail.com>
-    Copyright (c) 2015, SIL International
-    All rights reserved.
-    
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions are met:
-    
-    1. Redistributions of source code must retain the above copyright notice,
-       this list of conditions and the following disclaimer.
-    
-    2. Redistributions in binary form must reproduce the above copyright
-       notice, this list of conditions and the following disclaimer in the
-       documentation and/or other materials provided with the distribution.
-    
-    3. Neither the name of the copyright holder nor the names of its
-       contributors may be used to endorse or promote products derived from
-       this software without specific prior written permission.
-    
-    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
-    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
-    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
-    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
-    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
-    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
-    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
-    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
-    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
-    POSSIBILITY OF SUCH DAMAGE.
-*/
-
-#pragma once
-
-#include <cassert>
-#include <cstddef>
-#include <cstring>
-
-#include <iterator>
-
-//the code from LZ4
-#if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
-# define expect(expr,value)    (__builtin_expect ((expr),(value)) )
-#else
-# define expect(expr,value)    (expr)
-#endif
-#define likely(expr)     expect((expr) != 0, 1)
-#define unlikely(expr)   expect((expr) != 0, 0)
-////////////////////
-
-
-namespace
-{
-
-#if defined(_MSC_VER)
-typedef unsigned __int8 u8;
-typedef unsigned __int16 u16;
-typedef unsigned __int32 u32;
-typedef unsigned __int64 u64;
-#else
-#include <stdint.h>
-typedef uint8_t u8;
-typedef uint16_t u16;
-typedef uint32_t u32;
-typedef uint64_t u64;
-#endif
-
-ptrdiff_t const     MINMATCH  = 4;
-
-template<int S>
-inline 
-void unaligned_copy(void * d, void const * s) {
-  ::memcpy(d, s, S);
-}
-
-inline
-u8 * memcpy_nooverlap(u8 * d, u8 const * s, size_t n) {
-    size_t const WS = sizeof(unsigned long);
-    u8 const * e = s + n;
-    do 
-    {
-        unaligned_copy<WS>(d, s);
-        d += WS;
-        s += WS;
-    }
-    while (s < e);
-    d-=(s-e);
-    
-    return d;
-}
-
-
-inline
-u8 * memcpy_nooverlap_surpass(u8 * d, u8 const * s, size_t n) {
-    size_t const WS = sizeof(unsigned long);
-    size_t wn = n/WS;
-    while (wn--) 
-    {
-        unaligned_copy<WS>(d, s);
-        d += WS;
-        s += WS;
-    }
-    n &= WS-1;
-    while (n--) {*d++ = *s++; }
-    
-    return d;
-}
-
-
-inline 
-u8 * memcpy_(u8 * d, u8 const * s, size_t n) {
-    if (likely(d>s+sizeof(unsigned long)))
-        return memcpy_nooverlap(d,s,n);
-    else while (n--) *d++ = *s++;
-    return d;
-}
-
-} // end of anonymous namespace
-
-
diff --git a/gfx/graphite2/src/moz.build b/gfx/graphite2/src/moz.build
old mode 100644
new mode 100755
index d918f8ee9ff2..7fb0f2614304
--- a/gfx/graphite2/src/moz.build
+++ b/gfx/graphite2/src/moz.build
@@ -23,7 +23,6 @@ else:
 
 # This should contain all of the _SOURCES from files.mk, except *_machine.cpp
 UNIFIED_SOURCES += [
-    'Bidi.cpp',
     'CachedFace.cpp',
     'CmapCache.cpp',
     'Code.cpp',
diff --git a/gfx/layers/LayersLogging.cpp b/gfx/layers/LayersLogging.cpp
index 6cdbc22c840e..8af482785d88 100644
--- a/gfx/layers/LayersLogging.cpp
+++ b/gfx/layers/LayersLogging.cpp
@@ -348,6 +348,8 @@ AppendToString(std::stringstream& aStream, gfx::SurfaceType aType,
     aStream << "SurfaceType::RECORDING"; break;
   case SurfaceType::TILED:
     aStream << "SurfaceType::TILED"; break;
+  case SurfaceType::DATA_SHARED:
+    aStream << "SurfaceType::DATA_SHARED"; break;
   default:
     NS_ERROR("unknown surface type");
     aStream << "???";
diff --git a/gfx/layers/SourceSurfaceSharedData.cpp b/gfx/layers/SourceSurfaceSharedData.cpp
new file mode 100644
index 000000000000..e0471baea944
--- /dev/null
+++ b/gfx/layers/SourceSurfaceSharedData.cpp
@@ -0,0 +1,140 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "SourceSurfaceSharedData.h"
+
+#include "mozilla/Likely.h"
+#include "mozilla/Types.h" // for decltype
+
+namespace mozilla {
+namespace gfx {
+
+bool
+SourceSurfaceSharedData::Init(const IntSize &aSize,
+                              int32_t aStride,
+                              SurfaceFormat aFormat)
+{
+  mSize = aSize;
+  mStride = aStride;
+  mFormat = aFormat;
+
+  size_t len = GetAlignedDataLength();
+  mBuf = new SharedMemoryBasic();
+  if (NS_WARN_IF(!mBuf->Create(len)) ||
+      NS_WARN_IF(!mBuf->Map(len))) {
+    mBuf = nullptr;
+    return false;
+  }
+
+  return true;
+}
+
+void
+SourceSurfaceSharedData::GuaranteePersistance()
+{
+  // Shared memory is not unmapped until we release SourceSurfaceSharedData.
+}
+
+void
+SourceSurfaceSharedData::AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
+                                                size_t& aHeapSizeOut,
+                                                size_t& aNonHeapSizeOut) const
+{
+  if (mBuf) {
+    aNonHeapSizeOut += GetAlignedDataLength();
+  }
+}
+
+uint8_t*
+SourceSurfaceSharedData::GetDataInternal() const
+{
+  mMutex.AssertCurrentThreadOwns();
+
+  // If we have an old buffer lingering, it is because we get reallocated to
+  // get a new handle to share, but there were still active mappings.
+  if (MOZ_UNLIKELY(mOldBuf)) {
+    MOZ_ASSERT(mMapCount > 0);
+    MOZ_ASSERT(mFinalized);
+    return static_cast<uint8_t*>(mOldBuf->memory());
+  }
+  return static_cast<uint8_t*>(mBuf->memory());
+}
+
+nsresult
+SourceSurfaceSharedData::ShareToProcess(base::ProcessId aPid,
+                                        SharedMemoryBasic::Handle& aHandle)
+{
+  MutexAutoLock lock(mMutex);
+
+  if (mClosed) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  bool shared = mBuf->ShareToProcess(aPid, &aHandle);
+  if (MOZ_UNLIKELY(!shared)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+void
+SourceSurfaceSharedData::CloseHandleInternal()
+{
+  mMutex.AssertCurrentThreadOwns();
+
+  if (mClosed) {
+    return;
+  }
+
+  if (mFinalized && mShared) {
+    mBuf->CloseHandle();
+    mClosed = true;
+  }
+}
+
+bool
+SourceSurfaceSharedData::ReallocHandle()
+{
+  MutexAutoLock lock(mMutex);
+  MOZ_ASSERT(mClosed);
+  MOZ_ASSERT(mFinalized);
+
+  size_t len = GetAlignedDataLength();
+  RefPtr<SharedMemoryBasic> buf = new SharedMemoryBasic();
+  if (NS_WARN_IF(!buf->Create(len)) ||
+      NS_WARN_IF(!buf->Map(len))) {
+    return false;
+  }
+
+  size_t copyLen = GetDataLength();
+  memcpy(buf->memory(), mBuf->memory(), copyLen);
+  buf->Protect(static_cast<char*>(buf->memory()), len, RightsRead);
+
+  if (mMapCount > 0 && !mOldBuf) {
+    mOldBuf = Move(mBuf);
+  }
+  mBuf = Move(buf);
+  mClosed = false;
+  mShared = false;
+  return true;
+}
+
+void
+SourceSurfaceSharedData::Finalize()
+{
+  MutexAutoLock lock(mMutex);
+  MOZ_ASSERT(!mClosed);
+  MOZ_ASSERT(!mFinalized);
+
+  size_t len = GetAlignedDataLength();
+  mBuf->Protect(static_cast<char*>(mBuf->memory()), len, RightsRead);
+
+  mFinalized = true;
+  CloseHandleInternal();
+}
+
+} // namespace gfx
+} // namespace mozilla
diff --git a/gfx/layers/SourceSurfaceSharedData.h b/gfx/layers/SourceSurfaceSharedData.h
new file mode 100644
index 000000000000..9a26ed26f5cd
--- /dev/null
+++ b/gfx/layers/SourceSurfaceSharedData.h
@@ -0,0 +1,168 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_GFX_SOURCESURFACESHAREDDATA_H_
+#define MOZILLA_GFX_SOURCESURFACESHAREDDATA_H_
+
+#include "mozilla/gfx/2D.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/ipc/SharedMemoryBasic.h"
+
+namespace mozilla {
+namespace gfx {
+
+/**
+ * This class is used to wrap shared (as in process) data buffers used by a
+ * source surface.
+ */
+class SourceSurfaceSharedData final : public DataSourceSurface
+{
+  typedef mozilla::ipc::SharedMemoryBasic SharedMemoryBasic;
+
+public:
+  MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(SourceSurfaceSharedData, override)
+
+  SourceSurfaceSharedData()
+    : mMutex("SourceSurfaceSharedData")
+    , mStride(0)
+    , mMapCount(0)
+    , mFormat(SurfaceFormat::UNKNOWN)
+    , mClosed(false)
+    , mFinalized(false)
+    , mShared(false)
+  {
+  }
+
+  bool Init(const IntSize &aSize,
+            int32_t aStride,
+            SurfaceFormat aFormat);
+
+  uint8_t* GetData() override
+  {
+    MutexAutoLock lock(mMutex);
+    return GetDataInternal();
+  }
+
+  int32_t Stride() override { return mStride; }
+
+  SurfaceType GetType() const override { return SurfaceType::DATA_SHARED; }
+  IntSize GetSize() const override { return mSize; }
+  SurfaceFormat GetFormat() const override { return mFormat; }
+
+  void GuaranteePersistance() override;
+
+  void AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
+                              size_t& aHeapSizeOut,
+                              size_t& aNonHeapSizeOut) const override;
+
+  bool OnHeap() const override
+  {
+    return false;
+  }
+
+  /**
+   * Although Map (and Moz2D in general) isn't normally threadsafe,
+   * we want to allow it for SourceSurfaceSharedData since it should
+   * always be fine (for reading at least).
+   *
+   * This is the same as the base class implementation except using
+   * mMapCount instead of mIsMapped since that breaks for multithread.
+   *
+   * Additionally if a reallocation happened while there were active
+   * mappings, then we guarantee that GetData will continue to return
+   * the same data pointer by retaining the old shared buffer until
+   * the last mapping is freed via Unmap.
+   */
+  bool Map(MapType, MappedSurface *aMappedSurface) override
+  {
+    MutexAutoLock lock(mMutex);
+    ++mMapCount;
+    aMappedSurface->mData = GetDataInternal();
+    aMappedSurface->mStride = mStride;
+    return true;
+  }
+
+  void Unmap() override
+  {
+    MutexAutoLock lock(mMutex);
+    MOZ_ASSERT(mMapCount > 0);
+    if (--mMapCount == 0) {
+      mOldBuf = nullptr;
+    }
+  }
+
+  /**
+   * Get a handle to share to another process for this buffer. Returns:
+   *   NS_OK -- success, aHandle is valid.
+   *   NS_ERROR_NOT_AVAILABLE -- handle was closed, need to reallocate.
+   *   NS_ERROR_FAILURE -- failed to create a handle to share.
+   */
+  nsresult ShareToProcess(base::ProcessId aPid,
+                          SharedMemoryBasic::Handle& aHandle);
+
+  /**
+   * Indicates the buffer is not expected to be shared with any more processes.
+   * May release the handle if possible (see CloseHandleInternal). */
+  void FinishedSharing()
+  {
+    MutexAutoLock lock(mMutex);
+    mShared = true;
+    CloseHandleInternal();
+  }
+
+  /**
+   * Allocate a new shared memory buffer so that we can get a new handle for
+   * sharing to new processes. ShareToProcess must have failed with
+   * NS_ERROR_NOT_AVAILABLE in order for this to be safe to call. Returns true
+   * if the operation succeeds. If it fails, there is no state change.
+   */
+  bool ReallocHandle();
+
+  /**
+   * Indicates we have finished writing to the buffer and it may be marked as
+   * read only. May release the handle if possible (see CloseHandleInternal).
+   */
+  void Finalize();
+
+private:
+  ~SourceSurfaceSharedData() override
+  {
+    MOZ_ASSERT(mMapCount == 0);
+  }
+
+  uint8_t* GetDataInternal() const;
+
+  size_t GetDataLength() const
+  {
+    return static_cast<size_t>(mStride) * mSize.height;
+  }
+
+  size_t GetAlignedDataLength() const
+  {
+    return mozilla::ipc::SharedMemory::PageAlignedSize(GetDataLength());
+  }
+
+  /**
+   * Attempt to close the handle. Only if the buffer has been both finalized
+   * and we have completed sharing will it be released.
+   */
+  void CloseHandleInternal();
+
+  Mutex mMutex;
+  int32_t mStride;
+  int32_t mMapCount;
+  IntSize mSize;
+  RefPtr<SharedMemoryBasic> mBuf;
+  RefPtr<SharedMemoryBasic> mOldBuf;
+  SurfaceFormat mFormat;
+  bool mClosed : 1;
+  bool mFinalized : 1;
+  bool mShared : 1;
+};
+
+} // namespace gfx
+} // namespace mozilla
+
+#endif /* MOZILLA_GFX_SOURCESURFACESHAREDDATA_H_ */
diff --git a/gfx/layers/SourceSurfaceVolatileData.cpp b/gfx/layers/SourceSurfaceVolatileData.cpp
new file mode 100644
index 000000000000..ac3b7a0e1060
--- /dev/null
+++ b/gfx/layers/SourceSurfaceVolatileData.cpp
@@ -0,0 +1,52 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "SourceSurfaceVolatileData.h"
+
+#include "gfxAlphaRecovery.h"
+#include "mozilla/Likely.h"
+#include "mozilla/Types.h" // for decltype
+
+namespace mozilla {
+namespace gfx {
+
+bool
+SourceSurfaceVolatileData::Init(const IntSize &aSize,
+                                int32_t aStride,
+                                SurfaceFormat aFormat)
+{
+  mSize = aSize;
+  mStride = aStride;
+  mFormat = aFormat;
+
+  size_t alignment = size_t(1) << gfxAlphaRecovery::GoodAlignmentLog2();
+  mVBuf = new VolatileBuffer();
+  if (MOZ_UNLIKELY(!mVBuf->Init(aStride * aSize.height, alignment))) {
+    mVBuf = nullptr;
+    return false;
+  }
+
+  return true;
+}
+
+void
+SourceSurfaceVolatileData::GuaranteePersistance()
+{
+  MOZ_ASSERT_UNREACHABLE("Should use SourceSurfaceRawData wrapper!");
+}
+
+void
+SourceSurfaceVolatileData::AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
+                                                  size_t& aHeapSizeOut,
+                                                  size_t& aNonHeapSizeOut) const
+{
+  if (mVBuf) {
+    aHeapSizeOut += mVBuf->HeapSizeOfExcludingThis(aMallocSizeOf);
+    aNonHeapSizeOut += mVBuf->NonHeapSizeOfExcludingThis();
+  }
+}
+
+} // namespace gfx
+} // namespace mozilla
diff --git a/gfx/layers/SourceSurfaceVolatileData.h b/gfx/layers/SourceSurfaceVolatileData.h
new file mode 100644
index 000000000000..7641733621a6
--- /dev/null
+++ b/gfx/layers/SourceSurfaceVolatileData.h
@@ -0,0 +1,108 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_GFX_SOURCESURFACEVOLATILEDATA_H_
+#define MOZILLA_GFX_SOURCESURFACEVOLATILEDATA_H_
+
+#include "mozilla/gfx/2D.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/VolatileBuffer.h"
+
+namespace mozilla {
+namespace gfx {
+
+/**
+ * This class is used to wrap volatile data buffers used for source surfaces.
+ * The Map and Unmap semantics are used to guarantee that the volatile data
+ * buffer is not freed by the operating system while the surface is in active
+ * use. If GetData is expected to return a non-null value without a
+ * corresponding Map call (and verification of the result), the surface data
+ * should be wrapped in a temporary SourceSurfaceRawData with a ScopedMap
+ * closure.
+ */
+class SourceSurfaceVolatileData : public DataSourceSurface
+{
+public:
+  MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(SourceSurfaceVolatileData, override)
+
+  SourceSurfaceVolatileData()
+    : mMutex("SourceSurfaceVolatileData")
+    , mStride(0)
+    , mMapCount(0)
+    , mFormat(SurfaceFormat::UNKNOWN)
+  {
+  }
+
+  bool Init(const IntSize &aSize,
+            int32_t aStride,
+            SurfaceFormat aFormat);
+
+  uint8_t *GetData() override { return mVBufPtr; }
+  int32_t Stride() override { return mStride; }
+
+  SurfaceType GetType() const override { return SurfaceType::DATA; }
+  IntSize GetSize() const override { return mSize; }
+  SurfaceFormat GetFormat() const override { return mFormat; }
+
+  void GuaranteePersistance() override;
+
+  void AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
+                              size_t& aHeapSizeOut,
+                              size_t& aNonHeapSizeOut) const override;
+
+  bool OnHeap() const override
+  {
+    return mVBuf->OnHeap();
+  }
+
+  // Althought Map (and Moz2D in general) isn't normally threadsafe,
+  // we want to allow it for SourceSurfaceVolatileData since it should
+  // always be fine (for reading at least).
+  //
+  // This is the same as the base class implementation except using
+  // mMapCount instead of mIsMapped since that breaks for multithread.
+  bool Map(MapType, MappedSurface *aMappedSurface) override
+  {
+    MutexAutoLock lock(mMutex);
+    if (mMapCount == 0) {
+      mVBufPtr = mVBuf;
+    }
+    if (mVBufPtr.WasBufferPurged()) {
+      return false;
+    }
+    aMappedSurface->mData = mVBufPtr;
+    aMappedSurface->mStride = mStride;
+    ++mMapCount;
+    return true;
+  }
+
+  void Unmap() override
+  {
+    MutexAutoLock lock(mMutex);
+    MOZ_ASSERT(mMapCount > 0);
+    if (--mMapCount == 0) {
+      mVBufPtr = nullptr;
+    }
+  }
+
+private:
+  ~SourceSurfaceVolatileData() override
+  {
+    MOZ_ASSERT(mMapCount == 0);
+  }
+
+  Mutex mMutex;
+  int32_t mStride;
+  int32_t mMapCount;
+  IntSize mSize;
+  RefPtr<VolatileBuffer> mVBuf;
+  VolatileBufferPtr<uint8_t> mVBufPtr;
+  SurfaceFormat mFormat;
+};
+
+} // namespace gfx
+} // namespace mozilla
+
+#endif /* MOZILLA_GFX_SOURCESURFACEVOLATILEDATA_H_ */
diff --git a/gfx/layers/apz/src/GestureEventListener.cpp b/gfx/layers/apz/src/GestureEventListener.cpp
index 7fd07f3ff741..e4024127d0eb 100644
--- a/gfx/layers/apz/src/GestureEventListener.cpp
+++ b/gfx/layers/apz/src/GestureEventListener.cpp
@@ -8,6 +8,7 @@
 #include <math.h>                       // for fabsf
 #include <stddef.h>                     // for size_t
 #include "AsyncPanZoomController.h"     // for AsyncPanZoomController
+#include "InputBlockState.h"            // for TouchBlockState
 #include "base/task.h"                  // for CancelableTask, etc
 #include "gfxPrefs.h"                   // for gfxPrefs
 #include "mozilla/SizePrintfMacros.h"   // for PRIuSIZE
diff --git a/gfx/layers/moz.build b/gfx/layers/moz.build
index 92080206e946..7df56be0bfce 100644
--- a/gfx/layers/moz.build
+++ b/gfx/layers/moz.build
@@ -201,6 +201,8 @@ EXPORTS.mozilla.layers += [
     'opengl/TextureHostOGL.h',
     'PersistentBufferProvider.h',
     'RenderTrace.h',
+    'SourceSurfaceSharedData.h',
+    'SourceSurfaceVolatileData.h',
     'TextureWrapperImage.h',
     'TransactionIdAllocator.h',
 ]
@@ -373,6 +375,8 @@ UNIFIED_SOURCES += [
     'RenderTrace.cpp',
     'RotatedBuffer.cpp',
     'ShareableCanvasLayer.cpp',
+    'SourceSurfaceSharedData.cpp',
+    'SourceSurfaceVolatileData.cpp',
     'TextureWrapperImage.cpp',
 ]
 
diff --git a/gfx/tests/crashtests/crashtests.list b/gfx/tests/crashtests/crashtests.list
index e7a29ca0ac74..c57b7935651c 100644
--- a/gfx/tests/crashtests/crashtests.list
+++ b/gfx/tests/crashtests/crashtests.list
@@ -114,7 +114,7 @@ load 798853.html # bug 868792
 load 805760-1.html
 skip-if(Android) load 815489.html # bug 1216304
 load 836225-1.html
-asserts-if(stylo,2) load 839745-1.html # bug 1324669
+load 839745-1.html
 load 856784-1.html
 load 893572-1.html
 load 893572-2.html
@@ -122,7 +122,7 @@ load 893572-3.html
 load 893572-4.html
 pref(layers.force-active,true) load 914457-1.html
 load 944579.svg
-asserts-if(stylo,2) load 944579.html # bug 1324669
+load 944579.html
 asserts-if(stylo,1) pref(security.fileuri.strict_origin_policy,false) load 950000.html # bug 1324700
 load 1034403-1.html
 load 1205900.html
@@ -130,6 +130,6 @@ load 1134549-1.svg
 load balinese-letter-spacing.html
 load 1216832-1.html
 load 1225125-1.html
-asserts-if(stylo,2) load 1308394.html # bug 1324669
+load 1308394.html
 skip-if(stylo) load 1317403-1.html # bug 1331533
 load 1325159-1.html
diff --git a/gfx/thebes/gfxFont.cpp b/gfx/thebes/gfxFont.cpp
index 59965bbcb3bb..8171bb4db470 100644
--- a/gfx/thebes/gfxFont.cpp
+++ b/gfx/thebes/gfxFont.cpp
@@ -47,7 +47,6 @@
 
 #include "harfbuzz/hb.h"
 #include "harfbuzz/hb-ot.h"
-#include "graphite2/Font.h"
 
 #include <algorithm>
 #include <limits>
diff --git a/gfx/thebes/gfxUtils.cpp b/gfx/thebes/gfxUtils.cpp
index f958a56932da..d36bbf770a40 100644
--- a/gfx/thebes/gfxUtils.cpp
+++ b/gfx/thebes/gfxUtils.cpp
@@ -885,7 +885,7 @@ gfxUtils::CopySurfaceToDataSourceSurfaceWithFormat(SourceSurface* aSurface,
 
   Rect bounds(0, 0, aSurface->GetSize().width, aSurface->GetSize().height);
 
-  if (aSurface->GetType() != SurfaceType::DATA) {
+  if (!aSurface->IsDataSourceSurface()) {
     // If the surface is NOT of type DATA then its data is not mapped into main
     // memory. Format conversion is probably faster on the GPU, and by doing it
     // there we can avoid any expensive uploads/readbacks except for (possibly)
diff --git a/image/SurfaceCache.cpp b/image/SurfaceCache.cpp
index ee2fa0ee600c..dd8982ce97f2 100644
--- a/image/SurfaceCache.cpp
+++ b/image/SurfaceCache.cpp
@@ -15,9 +15,9 @@
 #include "mozilla/DebugOnly.h"
 #include "mozilla/Likely.h"
 #include "mozilla/Move.h"
-#include "mozilla/Mutex.h"
 #include "mozilla/Pair.h"
 #include "mozilla/RefPtr.h"
+#include "mozilla/StaticMutex.h"
 #include "mozilla/StaticPtr.h"
 #include "mozilla/Tuple.h"
 #include "nsIMemoryReporter.h"
@@ -55,6 +55,9 @@ class SurfaceCacheImpl;
 // The single surface cache instance.
 static StaticRefPtr<SurfaceCacheImpl> sInstance;
 
+// The mutex protecting the surface cache.
+static StaticMutex sInstanceMutex;
+
 ///////////////////////////////////////////////////////////////////////////////
 // SurfaceCache Implementation
 ///////////////////////////////////////////////////////////////////////////////
@@ -391,7 +394,6 @@ public:
                    uint32_t aSurfaceCacheSize)
     : mExpirationTracker(aSurfaceCacheExpirationTimeMS)
     , mMemoryPressureObserver(new MemoryPressureObserver)
-    , mMutex("SurfaceCache")
     , mDiscardFactor(aSurfaceCacheDiscardFactor)
     , mMaxCost(aSurfaceCacheSize)
     , mAvailableCost(aSurfaceCacheSize)
@@ -418,8 +420,6 @@ private:
 public:
   void InitMemoryReporter() { RegisterWeakMemoryReporter(this); }
 
-  Mutex& GetMutex() { return mMutex; }
-
   InsertOutcome Insert(NotNull<ISurfaceProvider*> aProvider,
                        bool                       aSetAvailable)
   {
@@ -786,7 +786,7 @@ public:
                  nsISupports*             aData,
                  bool                     aAnonymize) override
   {
-    MutexAutoLock lock(mMutex);
+    StaticMutexAutoLock lock(sInstanceMutex);
 
     // We have explicit memory reporting for the surface cache which is more
     // accurate than the cost metrics we report here, but these metrics are
@@ -894,8 +894,8 @@ private:
   protected:
     virtual void NotifyExpired(CachedSurface* aSurface) override
     {
+      StaticMutexAutoLock lock(sInstanceMutex);
       if (sInstance) {
-        MutexAutoLock lock(sInstance->GetMutex());
         sInstance->Remove(WrapNotNull(aSurface));
       }
     }
@@ -909,8 +909,8 @@ private:
                        const char* aTopic,
                        const char16_t*) override
     {
+      StaticMutexAutoLock lock(sInstanceMutex);
       if (sInstance && strcmp(aTopic, "memory-pressure") == 0) {
-        MutexAutoLock lock(sInstance->GetMutex());
         sInstance->DiscardForMemoryPressure();
       }
       return NS_OK;
@@ -925,7 +925,6 @@ private:
     ImageSurfaceCache> mImageCaches;
   SurfaceTracker                          mExpirationTracker;
   RefPtr<MemoryPressureObserver>        mMemoryPressureObserver;
-  Mutex                                   mMutex;
   const uint32_t                          mDiscardFactor;
   const Cost                              mMaxCost;
   Cost                                    mAvailableCost;
@@ -999,6 +998,7 @@ SurfaceCache::Initialize()
 /* static */ void
 SurfaceCache::Shutdown()
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_ASSERT(sInstance, "No singleton - was Shutdown() called twice?");
   sInstance = nullptr;
@@ -1008,11 +1008,11 @@ SurfaceCache::Shutdown()
 SurfaceCache::Lookup(const ImageKey         aImageKey,
                      const SurfaceKey&      aSurfaceKey)
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (!sInstance) {
     return LookupResult(MatchType::NOT_FOUND);
   }
 
-  MutexAutoLock lock(sInstance->GetMutex());
   return sInstance->Lookup(aImageKey, aSurfaceKey);
 }
 
@@ -1020,28 +1020,29 @@ SurfaceCache::Lookup(const ImageKey         aImageKey,
 SurfaceCache::LookupBestMatch(const ImageKey         aImageKey,
                               const SurfaceKey&      aSurfaceKey)
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (!sInstance) {
     return LookupResult(MatchType::NOT_FOUND);
   }
 
-  MutexAutoLock lock(sInstance->GetMutex());
   return sInstance->LookupBestMatch(aImageKey, aSurfaceKey);
 }
 
 /* static */ InsertOutcome
 SurfaceCache::Insert(NotNull<ISurfaceProvider*> aProvider)
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (!sInstance) {
     return InsertOutcome::FAILURE;
   }
 
-  MutexAutoLock lock(sInstance->GetMutex());
   return sInstance->Insert(aProvider, /* aSetAvailable = */ false);
 }
 
 /* static */ bool
 SurfaceCache::CanHold(const IntSize& aSize, uint32_t aBytesPerPixel /* = 4 */)
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (!sInstance) {
     return false;
   }
@@ -1053,6 +1054,7 @@ SurfaceCache::CanHold(const IntSize& aSize, uint32_t aBytesPerPixel /* = 4 */)
 /* static */ bool
 SurfaceCache::CanHold(size_t aSize)
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (!sInstance) {
     return false;
   }
@@ -1063,19 +1065,19 @@ SurfaceCache::CanHold(size_t aSize)
 /* static */ void
 SurfaceCache::SurfaceAvailable(NotNull<ISurfaceProvider*> aProvider)
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (!sInstance) {
     return;
   }
 
-  MutexAutoLock lock(sInstance->GetMutex());
   sInstance->SurfaceAvailable(aProvider);
 }
 
 /* static */ void
 SurfaceCache::LockImage(const ImageKey aImageKey)
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (sInstance) {
-    MutexAutoLock lock(sInstance->GetMutex());
     return sInstance->LockImage(aImageKey);
   }
 }
@@ -1083,8 +1085,8 @@ SurfaceCache::LockImage(const ImageKey aImageKey)
 /* static */ void
 SurfaceCache::UnlockImage(const ImageKey aImageKey)
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (sInstance) {
-    MutexAutoLock lock(sInstance->GetMutex());
     return sInstance->UnlockImage(aImageKey);
   }
 }
@@ -1092,8 +1094,8 @@ SurfaceCache::UnlockImage(const ImageKey aImageKey)
 /* static */ void
 SurfaceCache::UnlockEntries(const ImageKey aImageKey)
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (sInstance) {
-    MutexAutoLock lock(sInstance->GetMutex());
     return sInstance->UnlockEntries(aImageKey);
   }
 }
@@ -1101,8 +1103,8 @@ SurfaceCache::UnlockEntries(const ImageKey aImageKey)
 /* static */ void
 SurfaceCache::RemoveImage(const ImageKey aImageKey)
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (sInstance) {
-    MutexAutoLock lock(sInstance->GetMutex());
     sInstance->RemoveImage(aImageKey);
   }
 }
@@ -1110,8 +1112,8 @@ SurfaceCache::RemoveImage(const ImageKey aImageKey)
 /* static */ void
 SurfaceCache::DiscardAll()
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (sInstance) {
-    MutexAutoLock lock(sInstance->GetMutex());
     sInstance->DiscardAll();
   }
 }
@@ -1121,22 +1123,22 @@ SurfaceCache::CollectSizeOfSurfaces(const ImageKey                  aImageKey,
                                     nsTArray<SurfaceMemoryCounter>& aCounters,
                                     MallocSizeOf                    aMallocSizeOf)
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (!sInstance) {
     return;
   }
 
-  MutexAutoLock lock(sInstance->GetMutex());
   return sInstance->CollectSizeOfSurfaces(aImageKey, aCounters, aMallocSizeOf);
 }
 
 /* static */ size_t
 SurfaceCache::MaximumCapacity()
 {
+  StaticMutexAutoLock lock(sInstanceMutex);
   if (!sInstance) {
     return 0;
   }
 
-  MutexAutoLock lock(sInstance->GetMutex());
   return sInstance->MaximumCapacity();
 }
 
diff --git a/image/test/gtest/TestDecodeToSurface.cpp b/image/test/gtest/TestDecodeToSurface.cpp
index 278cdb1fdc89..dd22d4308d9b 100644
--- a/image/test/gtest/TestDecodeToSurface.cpp
+++ b/image/test/gtest/TestDecodeToSurface.cpp
@@ -47,7 +47,7 @@ public:
                                 imgIContainer::DECODE_FLAGS_DEFAULT);
     ASSERT_TRUE(mSurface != nullptr);
 
-    EXPECT_EQ(SurfaceType::DATA, mSurface->GetType());
+    EXPECT_TRUE(mSurface->IsDataSourceSurface());
     EXPECT_TRUE(mSurface->GetFormat() == SurfaceFormat::B8G8R8X8 ||
                 mSurface->GetFormat() == SurfaceFormat::B8G8R8A8);
     EXPECT_EQ(mTestCase.mSize, mSurface->GetSize());
diff --git a/image/test/gtest/TestDecoders.cpp b/image/test/gtest/TestDecoders.cpp
index 0eba5b34a53c..d39b8e404a60 100644
--- a/image/test/gtest/TestDecoders.cpp
+++ b/image/test/gtest/TestDecoders.cpp
@@ -64,7 +64,7 @@ CheckDecoderState(const ImageTestCase& aTestCase, Decoder* aDecoder)
   RefPtr<SourceSurface> surface = currentFrame->GetSourceSurface();
 
   // Verify that the resulting surfaces matches our expectations.
-  EXPECT_EQ(SurfaceType::DATA, surface->GetType());
+  EXPECT_TRUE(surface->IsDataSourceSurface());
   EXPECT_TRUE(surface->GetFormat() == SurfaceFormat::B8G8R8X8 ||
               surface->GetFormat() == SurfaceFormat::B8G8R8A8);
   EXPECT_EQ(aTestCase.mOutputSize, surface->GetSize());
diff --git a/js/src/builtin/Intl.cpp b/js/src/builtin/Intl.cpp
index f905a1487d02..a81b98871793 100644
--- a/js/src/builtin/Intl.cpp
+++ b/js/src/builtin/Intl.cpp
@@ -3503,7 +3503,6 @@ js::GlobalObject::addPluralRulesConstructor(JSContext* cx, HandleObject intl)
         const HeapSlot& slot = global->getReservedSlotRef(PLURAL_RULES_PROTO);
         if (!slot.isUndefined()) {
             MOZ_ASSERT(slot.isObject());
-            MOZ_ASSERT(slot.toObject().is<PluralRulesObject>());
             JS_ReportErrorASCII(cx,
                                 "the PluralRules constructor can't be added "
                                 "multiple times in the same global");
diff --git a/js/src/jit-test/tests/auto-regress/bug1334573.js b/js/src/jit-test/tests/auto-regress/bug1334573.js
new file mode 100644
index 000000000000..caa89b118296
--- /dev/null
+++ b/js/src/jit-test/tests/auto-regress/bug1334573.js
@@ -0,0 +1,6 @@
+// |jit-test| error:Error
+
+if (this.Intl) {
+    addIntlExtras(Intl);
+    addIntlExtras(Intl);
+}
diff --git a/layout/base/crashtests/crashtests.list b/layout/base/crashtests/crashtests.list
index d6f4606fb636..1c3041e9fac4 100644
--- a/layout/base/crashtests/crashtests.list
+++ b/layout/base/crashtests/crashtests.list
@@ -222,7 +222,7 @@ load 406675-1.html
 load 408292.html
 load 408299.html
 load 408450-1.xhtml
-asserts-if(stylo,2) load 409461-1.xhtml # bug 1324669
+load 409461-1.xhtml
 load 409513.html
 load 410967.html
 load 411870-1.html
@@ -243,7 +243,7 @@ load 422276.html
 asserts(0-1) load 423107-1.xhtml # bug 866955
 load 425981-1.html
 asserts-if(stylo,1) load 428113.xhtml # bug 1329454
-asserts-if(stylo,1) load 428138-1.html # bug 1324669
+load 428138-1.html
 load 428448-1.html
 load 429088-1.html
 load 429088-2.html
@@ -325,7 +325,7 @@ load 499741-1.xhtml
 load 499841-1.xhtml
 load 499858-1.xhtml
 load 500467-1.html
-asserts-if(stylo,2) load 501878-1.html # bug 1324669
+load 501878-1.html
 asserts-if(stylo,4) load 503936-1.html # bug 1324658
 load 507119.html
 load 514104-1.xul
@@ -376,7 +376,7 @@ load 597924-1.html
 load 606432-1.html
 load 609821-1.xhtml
 load 613817-1.svg
-asserts-if(stylo,2) load 615146-1.html # bug 1324669
+load 615146-1.html
 load 615781-1.xhtml
 load 616495-single-side-composite-color-border.html
 load 629035-1.html
@@ -462,7 +462,7 @@ load 1001237.html
 load 1009036.html
 asserts-if(stylo,1) load 1043163-1.html # bug 1324647
 load 1061028.html
-asserts-if(stylo,2-3) load 1107508-1.html # bug 1324669
+load 1107508-1.html
 load 1116104.html
 load 1127198-1.html
 load 1140198.html
diff --git a/layout/forms/crashtests/crashtests.list b/layout/forms/crashtests/crashtests.list
index c89d8755aac5..33446b596e9e 100644
--- a/layout/forms/crashtests/crashtests.list
+++ b/layout/forms/crashtests/crashtests.list
@@ -63,7 +63,7 @@ load 960277-2.html
 load 997709-1.html
 load 1102791.html
 skip-if(stylo) load 1140216.html # bug 1323693
-asserts-if(stylo,11) load 1182414.html # bug 1324687
+asserts-if(stylo,9) load 1182414.html # bug 1324687
 load 1212688.html
 load 1228670.xhtml
 asserts-if(stylo,4-5) load 1279354.html # bug 1324671
diff --git a/layout/generic/crashtests/crashtests.list b/layout/generic/crashtests/crashtests.list
index b601dfdb3aeb..5a2feff85f4a 100644
--- a/layout/generic/crashtests/crashtests.list
+++ b/layout/generic/crashtests/crashtests.list
@@ -186,8 +186,8 @@ load 400190.html
 skip-if(stylo) load 400223-1.html # bug 1323652
 load 400232-1.html
 load 400244-1.html
-asserts-if(stylo,2) load 400768-1.xhtml # bug 1324669
-asserts-if(stylo,2) load 400768-2.xhtml # bug 1324669
+load 400768-1.xhtml
+load 400768-2.xhtml
 load 401042-1.xhtml
 load 402380-1.html
 load 402380-2.html
@@ -242,7 +242,7 @@ load 416165.html
 load 416264-1.html
 load 416476-1.html
 load 417109-1.xhtml
-asserts-if(stylo,2) load 417848-1.xhtml # bug 1324669
+load 417848-1.xhtml
 load 417902-1.html
 load 417902-2.html
 load 418532-1.html
@@ -282,7 +282,7 @@ load 436822-1.html
 load 436823.html
 load 436969-1.html
 skip-if(stylo) load 437156-1.html # bug 1323652
-asserts-if(stylo,2) load 437565-1.xhtml # bug 1324669
+load 437565-1.xhtml
 load 437565-2.xhtml
 load 437565-3.xhtml
 load 438259-1.html
@@ -424,7 +424,7 @@ load 586806-3.html
 load 586973-1.html
 load 589002-1.html
 load 590404.html
-asserts-if(stylo,2) load 591141.html # bug 1324669
+load 591141.html
 load 592118.html
 load 594808-1.html
 asserts-if(stylo,4) load 595435-1.xhtml # bug 1324640
@@ -439,7 +439,7 @@ load 604843.html
 load 605340.html
 load 606642.xhtml
 load 613455-1.svg
-asserts-if(stylo,2) load 613629-1.xhtml # bug 1324669
+load 613629-1.xhtml
 load 616052-1.html
 load 619021.html
 load 621424-1.html
@@ -465,7 +465,7 @@ load 679933-1.html
 load 681489-1.html
 load 682649-1.html
 load 683702-1.xhtml
-asserts-if(stylo,2) load 683712.html # bug 1324669
+load 683712.html
 load 688996-1.html
 load 688996-2.html
 load 691210.html
@@ -552,7 +552,7 @@ load 893523.html
 asserts(0-3) load 898871.html # bug 479160 - mostly OSX, sometimes Windows
 asserts(0-3) load 914501.html # bug 1144852 - all platforms
 load 914891.html
-asserts-if(stylo,2) load 915475.xhtml # bug 1324669
+load 915475.xhtml
 load 927558.html
 load 943509-1.html
 asserts(2-8) asserts-if(stylo,0) load 944909-1.html
@@ -572,8 +572,8 @@ asserts(1-2) asserts-if(stylo,0) load 1015563-1.html
 asserts(1-2) asserts-if(stylo,0) load 1015563-2.html
 asserts(0-300) load 1015844.html # bug 574889
 pref(font.size.inflation.minTwips,200) load 1032450.html
-asserts-if(stylo,0-3) load 1032613-1.svg # bug 1324669
-asserts-if(stylo,2-6) load 1032613-2.html # bug 1324669
+load 1032613-1.svg
+load 1032613-2.html
 load 1037903.html
 asserts-if(stylo,1) load 1039454-1.html # bug 1324647
 load 1042489.html
diff --git a/layout/reftests/bidi/reftest-stylo.list b/layout/reftests/bidi/reftest-stylo.list
index a6c53d081502..b2798f2a8311 100644
--- a/layout/reftests/bidi/reftest-stylo.list
+++ b/layout/reftests/bidi/reftest-stylo.list
@@ -80,8 +80,8 @@ fails == 267459-1.html 267459-1.html
 fails == 267459-2.html 267459-2.html
 == 299065-1.html 299065-1.html
 == 305643-1.html 305643-1.html
-fails == 332655-1.html 332655-1.html
-fails == 332655-2.html 332655-2.html
+fails asserts-if(stylo,7) == 332655-1.html 332655-1.html # bug 1335314
+fails asserts-if(stylo,7) == 332655-2.html 332655-2.html # bug 1335314
 fails == 381279-1.html 381279-1.html
 fails == 386339.html 386339.html
 fails == 409375.html 409375.html
diff --git a/layout/reftests/bugs/reftest-stylo.list b/layout/reftests/bugs/reftest-stylo.list
index 38007dba546c..45f4f92dd9c2 100644
--- a/layout/reftests/bugs/reftest-stylo.list
+++ b/layout/reftests/bugs/reftest-stylo.list
@@ -201,8 +201,8 @@ fails == 210094-1b.html 210094-1b.html
 fails == 210094-1c.html 210094-1c.html
 fails == 210876-1.html 210876-1.html
 == 211931-1.html 211931-1.html
-fails == 212563-1.html 212563-1.html
-== 212563-2.html 212563-2.html
+fails asserts-if(stylo,1) == 212563-1.html 212563-1.html # bug 1324683
+asserts-if(stylo,1) == 212563-2.html 212563-2.html # bug 1324683
 fails == 213834-1.html 213834-1.html
 fails == 214077-1a.html 214077-1a.html
 fails == 214077-1b.html 214077-1b.html
@@ -574,7 +574,7 @@ fails == 364989-1.html 364989-1.html
 fails == 365173-1.html 365173-1.html
 == 366207-1.xul 366207-1.xul
 == 366616-1.xul 366616-1.xul
-fails == 367220-1.html 367220-1.html
+fails asserts-if(stylo,30) == 367220-1.html 367220-1.html # bug 1324704
 == 367247-s-visible.html 367247-s-visible.html
 == 367247-s-hidden.html 367247-s-hidden.html
 == 367247-s-auto.html 367247-s-auto.html
@@ -605,7 +605,7 @@ fails == 368020-2.html 368020-2.html
 fails == 368020-3.html 368020-3.html
 fails pref(layout.css.box-decoration-break.enabled,true) == 368020-5.html 368020-5.html
 == 368155-1.xhtml 368155-1.xhtml
-fails asserts(4) == 368155-negative-margins-1.html 368155-negative-margins-1.html
+fails asserts(4-8) == 368155-negative-margins-1.html 368155-negative-margins-1.html
 # we can't test this because there's antialiasing involved, and our comparison
 # is too exact
 # == 368247-1.html 368247-1.html
@@ -617,7 +617,7 @@ fails == 368504-2.html 368504-2.html
 == 368504-4.html 368504-4.html
 == 368504-5.html 368504-5.html
 fails == 368504-6.html 368504-6.html
-fails == 368622-1.html 368622-1.html
+fails asserts-if(stylo,2) == 368622-1.html 368622-1.html # bug 1324704
 fails == 368651-1.html 368651-1.html
 == 369361-1.html 369361-1.html
 == 369361-2.html 369361-2.html
@@ -679,7 +679,7 @@ fails == 376375-1.html 376375-1.html
 == 376532-1.html 376532-1.html
 == 376532-2.html 376532-2.html
 == 376532-3.html 376532-3.html
-fails == 377603-1.html 377603-1.html
+fails asserts-if(stylo,2) == 377603-1.html 377603-1.html # bug 1324661
 == 377918.html 377918.html
 == 378535-1.html 378535-1.html
 fails == 378933-1.html 378933-1.html
@@ -771,7 +771,7 @@ fails == 386470-1b.html 386470-1b.html
 fails == 389074-1.html 389074-1.html
 # == 389224-1.html 389224-1.html
 # == 389224-2.html 389224-2.html
-fails == 389468-1.html 389468-1.html
+fails asserts-if(stylo,5) == 389468-1.html 389468-1.html # bug 1324661
 == 389623-1.html 389623-1.html
 == 389636-1.html 389636-1.html
 # == 389924-1a.html 389924-1a.html
@@ -1014,7 +1014,7 @@ fails == 420790-1.xhtml 420790-1.xhtml
 == 421419-1.html 421419-1.html
 == 421436-1a.html 421436-1a.html
 == 421436-1b.html 421436-1b.html
-fails == 421632-1.html 421632-1.html
+fails asserts-if(stylo,4) == 421632-1.html 421632-1.html # bug 1335314
 fails == 421710-1.html 421710-1.html
 fails-if(Android) fails-if(usesRepeatResampling) == 421885-1.xml 421885-1.xml
 == 421955-1.html 421955-1.html
@@ -1049,7 +1049,7 @@ fails == 424766-1.html 424766-1.html
 fails == 425972-2.html 425972-2.html
 # == 425972-1.html 425972-1.html
 fails == 426629-1.html 426629-1.html
-asserts(3) == 427017-1.xhtml 427017-1.xhtml
+asserts(3-6) == 427017-1.xhtml 427017-1.xhtml
 == 427129-scrollframe.html 427129-scrollframe.html
 == 427129-table.html 427129-table.html
 == 427129-image.html 427129-image.html
@@ -1160,7 +1160,7 @@ fails == 444015-1.html 444015-1.html
 fails == 444928-1.html 444928-1.html
 fails == 444928-2.html 444928-2.html
 fails == 444928-3.html 444928-3.html
-fails random == 445004-1.html 445004-1.html
+fails random asserts-if(stylo,2) == 445004-1.html 445004-1.html # bug 1324683
 == 445142-1a.html 445142-1a.html
 == 445142-1b.html 445142-1b.html
 == 445142-1c.html 445142-1c.html
@@ -1176,11 +1176,11 @@ fails-if(usesRepeatResampling) fails-if(Android) == 446100-1g.html 446100-1g.htm
 == 446100-1h.html 446100-1h.html
 fails == 447749-1.html 447749-1.html
 fuzzy(127,2) == 448193.html 448193.html
-fails == 449149-1a.html 449149-1a.html
-fails == 449149-1b.html 449149-1b.html
+fails asserts-if(stylo,8) == 449149-1a.html 449149-1a.html # bug 1324671
+fails asserts-if(stylo,8) == 449149-1b.html 449149-1b.html # bug 1324671
 # Retry the above with XBL scopes
-fails test-pref(dom.use_xbl_scopes_for_remote_xul,true) == 449149-1a.html 449149-1a.html
-fails test-pref(dom.use_xbl_scopes_for_remote_xul,true) == 449149-1b.html 449149-1b.html
+fails test-pref(dom.use_xbl_scopes_for_remote_xul,true) asserts-if(stylo,8) == 449149-1a.html 449149-1a.html # bug 1324671
+fails test-pref(dom.use_xbl_scopes_for_remote_xul,true) asserts-if(stylo,8) == 449149-1b.html 449149-1b.html # bug 1324671
 == 449149-2.html 449149-2.html
 == 449171-1.html 449171-1.html
 fails == 449362-1.html 449362-1.html
@@ -1327,8 +1327,8 @@ fails == 482592-1a.xhtml 482592-1a.xhtml
 fails == 482592-1b.xhtml 482592-1b.xhtml
 == 482659-1a.html 482659-1a.html
 == 482659-1b.html 482659-1b.html
-== 482659-1c.html 482659-1c.html
-== 482659-1d.html 482659-1d.html
+asserts-if(stylo,1) == 482659-1c.html 482659-1c.html # bug 1324683
+asserts-if(stylo,1) == 482659-1d.html 482659-1d.html # bug 1324683
 == 483565.xul 483565.xul
 == 484256-1.html 484256-1.html
 == 484256-2.html 484256-2.html
@@ -1362,7 +1362,7 @@ pref(browser.display.focus_ring_width,1) == 491180-2.html 491180-2.html
 == 491323-1.xul 491323-1.xul
 == 492239-1.xul 492239-1.xul
 == 492661-1.html 492661-1.html
-== 493968-1.html 493968-1.html
+asserts-if(stylo,1) == 493968-1.html 493968-1.html # bug 1324702
 == 494667-1.html 494667-1.html
 == 494667-2.html 494667-2.html
 == 495274-1.html 495274-1.html
@@ -1403,7 +1403,7 @@ fails == 502795-1.html 502795-1.html
 # Reftest for bug 503531 marked as failing; should be re-enabled when
 # bug 607548 gets resolved.
 # needs-focus fails == 503531-1.html 503531-1.html
-== 504032-1.html 504032-1.html
+asserts-if(stylo,1) == 504032-1.html 504032-1.html # bug 1324702
 == 505743-1.html 505743-1.html
 fails == 506481-1.html 506481-1.html
 fails == 507187-1.html 507187-1.html
@@ -1623,7 +1623,7 @@ fails == 605157-1.xhtml 605157-1.xhtml
 fails == 608636-1.html 608636-1.html
 == 608756-1a.html 608756-1a.html
 == 608756-1b.html 608756-1b.html
-== 608756-2.html 608756-2.html
+asserts-if(stylo,4) == 608756-2.html 608756-2.html # bug 1324633
 == 609272-1.html 609272-1.html
 # == 613433-1.html 613433-1.html
 # == 613433-1.html 613433-1.html
@@ -1767,7 +1767,7 @@ fails == 827799-1.html 827799-1.html
 == 841192-1.html 841192-1.html
 fails == 844178.html 844178.html
 == 846144-1.html 846144-1.html
-== 847850-1.html 847850-1.html
+asserts-if(stylo,1) == 847850-1.html 847850-1.html # bug 1324671
 fails == 848421-1.html 848421-1.html
 fails == 849407-1.html 849407-1.html
 == 849996-1.html 849996-1.html
@@ -1808,7 +1808,7 @@ fails == 960277-1.html 960277-1.html
 == 961887-1.html 961887-1.html
 == 961887-2.html 961887-2.html
 == 961887-3.html 961887-3.html
-fails == 966992-1.html 966992-1.html
+fails asserts-if(stylo,1) == 966992-1.html 966992-1.html # bug 1324671
 fails == 966510-1.html 966510-1.html
 fails == 966510-2.html 966510-2.html
 fuzzy-if(skiaContent,1,123) == 978911-1.svg 978911-1.svg
diff --git a/layout/reftests/canvas/reftest-stylo.list b/layout/reftests/canvas/reftest-stylo.list
index 352417e4473d..a8ba00777a75 100644
--- a/layout/reftests/canvas/reftest-stylo.list
+++ b/layout/reftests/canvas/reftest-stylo.list
@@ -9,51 +9,51 @@ fails == image-rendering-test.html image-rendering-test.html
 
 fails == size-change-1.html size-change-1.html
 
-== subpixel-1.html subpixel-1.html
+asserts-if(stylo,1) == subpixel-1.html subpixel-1.html # bug 1324700
 
-== text-ltr-left.html text-ltr-left.html
-== text-ltr-right.html text-ltr-right.html
-== text-rtl-left.html text-rtl-left.html
-== text-rtl-right.html text-rtl-right.html
+asserts-if(stylo,1) == text-ltr-left.html text-ltr-left.html # bug 1324700
+asserts-if(stylo,1) == text-ltr-right.html text-ltr-right.html # bug 1324700
+asserts-if(stylo,1) == text-rtl-left.html text-rtl-left.html # bug 1324700
+asserts-if(stylo,1) == text-rtl-right.html text-rtl-right.html # bug 1324700
 
-== text-ltr-start.html text-ltr-start.html
-== text-ltr-end.html text-ltr-end.html
-== text-ltr-left.html text-ltr-left.html
-== text-rtl-start.html text-rtl-start.html
-== text-rtl-end.html text-rtl-end.html
-== text-rtl-left.html text-rtl-left.html
+asserts-if(stylo,1) == text-ltr-start.html text-ltr-start.html # bug 1324700
+asserts-if(stylo,1) == text-ltr-end.html text-ltr-end.html # bug 1324700
+asserts-if(stylo,1) == text-ltr-left.html text-ltr-left.html # bug 1324700
+asserts-if(stylo,1) == text-rtl-start.html text-rtl-start.html # bug 1324700
+asserts-if(stylo,1) == text-rtl-end.html text-rtl-end.html # bug 1324700
+asserts-if(stylo,1) == text-rtl-left.html text-rtl-left.html # bug 1324700
 
-== text-ltr-left.html text-ltr-left.html
+asserts-if(stylo,1) == text-ltr-left.html text-ltr-left.html # bug 1324700
 
-fails == text-ltr-alignment-test.html text-ltr-alignment-test.html
-fails == text-rtl-alignment-test.html text-rtl-alignment-test.html
+fails asserts-if(stylo,1) == text-ltr-alignment-test.html text-ltr-alignment-test.html # bug 1324700
+fails asserts-if(stylo,1) == text-rtl-alignment-test.html text-rtl-alignment-test.html # bug 1324700
 
-== text-horzline-with-bottom.html text-horzline-with-bottom.html
-fails-if(azureSkia&&OSX>=1008) == text-horzline-with-top.html text-horzline-with-top.html
+asserts-if(stylo,1) == text-horzline-with-bottom.html text-horzline-with-bottom.html # bug 1324700
+fails-if(azureSkia&&OSX>=1008) asserts-if(stylo,1) == text-horzline-with-top.html text-horzline-with-top.html # bug 1324700
 
 # == text-big-stroke.html text-big-stroke.html
 # == text-big-stroke.html text-big-stroke.html
 
-fails == text-context-state-test.html text-context-state-test.html
-fails == text-font-inherit.html text-font-inherit.html
-fails == text-space-replace-test.html text-space-replace-test.html
+fails asserts-if(stylo,1) == text-context-state-test.html text-context-state-test.html # bug 1324700
+fails asserts-if(stylo,1) == text-font-inherit.html text-font-inherit.html # bug 1324700
+fails asserts-if(stylo,1) == text-space-replace-test.html text-space-replace-test.html # bug 1324700
 
-fails == text-no-frame-test.html text-no-frame-test.html
-fails == text-no-frame-2-test.html text-no-frame-2-test.html
-fails == text-not-in-doc-test.html text-not-in-doc-test.html
+fails asserts-if(stylo,1) == text-no-frame-test.html text-no-frame-test.html # bug 1324700
+fails asserts-if(stylo,1) == text-no-frame-2-test.html text-no-frame-2-test.html # bug 1324700
+fails asserts-if(stylo,1) == text-not-in-doc-test.html text-not-in-doc-test.html # bug 1324700
 
 # == text-bidi-ltr-test.html text-bidi-ltr-test.html
 # == text-bidi-ltr-test.html text-bidi-ltr-test.html
-fails == text-bidi-rtl-test.html text-bidi-rtl-test.html
+fails asserts-if(stylo,1) == text-bidi-rtl-test.html text-bidi-rtl-test.html # bug 1324700
 
-fails == text-font-lang.html text-font-lang.html
+fails asserts-if(stylo,4) == text-font-lang.html text-font-lang.html # bug 1324700
 
-fails == text-measure.html text-measure.html
-fails == text-small-caps-1.html text-small-caps-1.html
+fails asserts-if(stylo,1) == text-measure.html text-measure.html # bug 1324700
+fails asserts-if(stylo,1) == text-small-caps-1.html text-small-caps-1.html # bug 1324700
 
-fails == text-subpixel-1.html text-subpixel-1.html
+fails asserts-if(stylo,1) == text-subpixel-1.html text-subpixel-1.html # bug 1324700
 
-fails == strokeText-path.html strokeText-path.html
+fails asserts-if(stylo,1) == strokeText-path.html strokeText-path.html # bug 1324700
 
 # check that emoji character renders as something non-blank (for Apple Color Emoji font, bug 715798)
 # apparently fails on some 10.7 systems for unknown reasons, bug 804522.
@@ -62,7 +62,7 @@ fails == strokeText-path.html strokeText-path.html
 ## if they have an Emoji font installed when running the tests.)
 ## WAS: random-if(OSX==1007) == text-emoji.html text-emoji.html
 # With Skia canvas on OS X (bug 932958) it fails even on 10.8 and 10.10.
-random-if(cocoaWidget&&azureSkia) random-if(!cocoaWidget||OSX==1006||OSX==1007) == text-emoji.html text-emoji.html
+random-if(cocoaWidget&&azureSkia) random-if(!cocoaWidget||OSX==1006||OSX==1007) asserts-if(stylo,1) == text-emoji.html text-emoji.html # bug 1324700
 
 # azure quartz uses CGDrawLinearGradient instead of DrawShading
 # so we have less control over degenerate behaviour as tested by this
@@ -87,7 +87,7 @@ random-if(cocoaWidget&&azureSkia) random-if(!cocoaWidget||OSX==1006||OSX==1007)
 fails-if(azureQuartz&&OSX==1006) == 672646-alpha-radial-gradient.html 672646-alpha-radial-gradient.html
 fails == 674003-alpha-radial-gradient-superlum.html 674003-alpha-radial-gradient-superlum.html
 
-fails == 693610-1.html 693610-1.html
+fails asserts-if(stylo,1) == 693610-1.html 693610-1.html # bug 1324700
 
 == 726951-shadow-clips.html 726951-shadow-clips.html
 
@@ -100,15 +100,15 @@ fuzzy-if(azureSkia,1,15) fuzzy-if(skiaContent,1,20) == transformed-gradient.html
 # You get a little bit of rounding fuzz on OSX from transforming the paths between user space and device space
 == 784573-1.html 784573-1.html
 
-fails == 802658-1.html 802658-1.html
+fails asserts-if(stylo,1) == 802658-1.html 802658-1.html # bug 1324700
 == 1074733-1.html 1074733-1.html
-fails == 1107096-invisibles.html 1107096-invisibles.html
+fails asserts-if(stylo,1) == 1107096-invisibles.html 1107096-invisibles.html # bug 1324700
 == 1151821-1.html 1151821-1.html
 == 1201272-1.html 1201272-1.html
 == 1224976-1.html 1224976-1.html
 == 1238795-1.html 1238795-1.html
 == 1303534-1.html 1303534-1.html
 
-fails == 1304353-text-global-alpha-1.html 1304353-text-global-alpha-1.html
-fails == 1304353-text-global-alpha-2.html 1304353-text-global-alpha-2.html
-fails == 1304353-text-global-composite-op-1.html 1304353-text-global-composite-op-1.html
+fails asserts-if(stylo,1) == 1304353-text-global-alpha-1.html 1304353-text-global-alpha-1.html # bug 1324700
+fails asserts-if(stylo,1) == 1304353-text-global-alpha-2.html 1304353-text-global-alpha-2.html # bug 1324700
+fails asserts-if(stylo,1) == 1304353-text-global-composite-op-1.html 1304353-text-global-composite-op-1.html # bug 1324700
diff --git a/layout/reftests/css-animations/reftest-stylo.list b/layout/reftests/css-animations/reftest-stylo.list
index 86be4fbc0c62..994e75dfea93 100644
--- a/layout/reftests/css-animations/reftest-stylo.list
+++ b/layout/reftests/css-animations/reftest-stylo.list
@@ -15,9 +15,9 @@ fails == animate-preserves3d.html animate-preserves3d.html
 # test-pref(layers.offmainthreadcomposition.async-animations,false) == stacking-context-transform-none-animation.html stacking-context-transform-none-animation.html
 # == no-stacking-context-opacity-removing-animation-in-delay.html no-stacking-context-opacity-removing-animation-in-delay.html
 == no-stacking-context-transform-removing-animation-in-delay.html no-stacking-context-transform-removing-animation-in-delay.html
-== stacking-context-lose-opacity-1.html stacking-context-lose-opacity-1.html
+# == stacking-context-lose-opacity-1.html stacking-context-lose-opacity-1.html
 fails == stacking-context-lose-transform-none.html stacking-context-lose-transform-none.html
-== stacking-context-opacity-win-in-delay.html stacking-context-opacity-win-in-delay.html
+# == stacking-context-opacity-win-in-delay.html stacking-context-opacity-win-in-delay.html
 == stacking-context-opacity-win-in-delay-on-main-thread.html stacking-context-opacity-win-in-delay-on-main-thread.html
 == stacking-context-opacity-wins-over-transition.html stacking-context-opacity-wins-over-transition.html
 fails == stacking-context-transform-win-in-delay.html stacking-context-transform-win-in-delay.html
diff --git a/layout/reftests/css-grid/reftest-stylo.list b/layout/reftests/css-grid/reftest-stylo.list
index 915dbbefd34f..a1f491187c32 100644
--- a/layout/reftests/css-grid/reftest-stylo.list
+++ b/layout/reftests/css-grid/reftest-stylo.list
@@ -175,7 +175,7 @@ fails == grid-repeat-auto-fill-fit-008.html grid-repeat-auto-fill-fit-008.html
 fails == grid-repeat-auto-fill-fit-009.html grid-repeat-auto-fill-fit-009.html
 fails == grid-repeat-auto-fill-fit-010.html grid-repeat-auto-fill-fit-010.html
 fails == grid-repeat-auto-fill-fit-011.html grid-repeat-auto-fill-fit-011.html
-fails == grid-item-blockifying-001.html grid-item-blockifying-001.html
+fails asserts-if(stylo,144) == grid-item-blockifying-001.html grid-item-blockifying-001.html # bug 1335339
 fails == grid-fragmentation-001.html grid-fragmentation-001.html
 fails == grid-fragmentation-002.html grid-fragmentation-002.html
 fails == grid-fragmentation-003.html grid-fragmentation-003.html
@@ -196,7 +196,7 @@ fails == grid-fragmentation-017.html grid-fragmentation-017.html
 fails == grid-fragmentation-018.html grid-fragmentation-018.html
 fails == grid-fragmentation-019.html grid-fragmentation-019.html
 fails == grid-fragmentation-020.html grid-fragmentation-020.html
-fails == grid-fragmentation-021.html grid-fragmentation-021.html
+fails asserts-if(stylo,93) == grid-fragmentation-021.html grid-fragmentation-021.html # bug 1324704
 fails == grid-fragmentation-022.html grid-fragmentation-022.html
 fails == grid-fragmentation-023.html grid-fragmentation-023.html
 fails == grid-fragmentation-024.html grid-fragmentation-024.html
diff --git a/layout/reftests/forms/button/reftest-stylo.list b/layout/reftests/forms/button/reftest-stylo.list
index 96e0e00bfbac..c60879d440dd 100644
--- a/layout/reftests/forms/button/reftest-stylo.list
+++ b/layout/reftests/forms/button/reftest-stylo.list
@@ -39,4 +39,4 @@ fails == disabled-6.html disabled-6.html
 # == width-auto-size-rtl.html width-auto-size-rtl.html
 # == width-exact-fit-rtl.html width-exact-fit-rtl.html
 fails == display-grid-flex-columnset.html display-grid-flex-columnset.html
-== 1317351.html 1317351.html
+asserts-if(stylo,1) == 1317351.html 1317351.html # bug 1324671
diff --git a/layout/reftests/forms/input/color/reftest-stylo.list b/layout/reftests/forms/input/color/reftest-stylo.list
index 7b04b3e56b33..4735fd4ad887 100644
--- a/layout/reftests/forms/input/color/reftest-stylo.list
+++ b/layout/reftests/forms/input/color/reftest-stylo.list
@@ -1,15 +1,15 @@
 # DO NOT EDIT! This is a auto-generated temporary list for Stylo testing
 # Simple test. Should fail on platforms where input type color isn't activated
 # yet. The missing platform is Android (bug 875750).
-fails == input-color-1.html input-color-1.html
+fails asserts-if(stylo,4) == input-color-1.html input-color-1.html # bug 1324671
 
 default-preferences pref(dom.forms.color,true)
 
 # Despite the "default-preferences" line above, Android is still
 # excluded from some style in forms.css, which makes the following tests fail.
-fails == margin-padding-1.html margin-padding-1.html
-fails == block-invalidate-1.html block-invalidate-1.html
-fails == block-invalidate-2.html block-invalidate-2.html
-fails == transformations-1.html transformations-1.html
-fails == custom-style-1.html custom-style-1.html
-fails == custom-style-2.html custom-style-2.html
+fails asserts-if(stylo,16) == margin-padding-1.html margin-padding-1.html # bug 1324671
+fails asserts-if(stylo,1) == block-invalidate-1.html block-invalidate-1.html # bug 1324671
+fails asserts-if(stylo,1) == block-invalidate-2.html block-invalidate-2.html # bug 1324671
+fails asserts-if(stylo,14) == transformations-1.html transformations-1.html # bug 1324671
+fails asserts-if(stylo,1) == custom-style-1.html custom-style-1.html # bug 1324671
+fails asserts-if(stylo,1) == custom-style-2.html custom-style-2.html # bug 1324671
diff --git a/layout/reftests/forms/placeholder/reftest-stylo.list b/layout/reftests/forms/placeholder/reftest-stylo.list
index 35cc1b201779..3b2e9bb217b5 100644
--- a/layout/reftests/forms/placeholder/reftest-stylo.list
+++ b/layout/reftests/forms/placeholder/reftest-stylo.list
@@ -9,28 +9,28 @@
 # ::value (bug 648643), depending of the ::value behaviour (it could change the
 # caret colour and the text colour or just the text colour).
 
-fails == placeholder-1-text.html placeholder-1-text.html
-fails == placeholder-1-password.html placeholder-1-password.html
-fails == placeholder-1-textarea.html placeholder-1-textarea.html
+fails asserts-if(stylo,1) == placeholder-1-text.html placeholder-1-text.html # bug 1324671
+fails asserts-if(stylo,1) == placeholder-1-password.html placeholder-1-password.html # bug 1324671
+fails asserts-if(stylo,1) == placeholder-1-textarea.html placeholder-1-textarea.html # bug 1324671
 fails == placeholder-2.html placeholder-2.html
 fails == placeholder-2-textarea.html placeholder-2-textarea.html
-fails == placeholder-3.html placeholder-3.html
-fails == placeholder-4.html placeholder-4.html
-fails == placeholder-5.html placeholder-5.html
-fails == placeholder-6.html placeholder-6.html
-fails == placeholder-6-textarea.html placeholder-6-textarea.html
+fails asserts-if(stylo,1) == placeholder-3.html placeholder-3.html # bug 1324671
+fails asserts-if(stylo,1) == placeholder-4.html placeholder-4.html # bug 1324671
+fails asserts-if(stylo,1) == placeholder-5.html placeholder-5.html # bug 1324671
+fails asserts-if(stylo,1) == placeholder-6.html placeholder-6.html # bug 1324671
+fails asserts-if(stylo,1) == placeholder-6-textarea.html placeholder-6-textarea.html # bug 1324671
 # needs-focus == placeholder-7.html placeholder-7.html
 # needs-focus == placeholder-8.html placeholder-8.html
 # needs-focus == placeholder-9.html placeholder-9.html
-fails needs-focus == placeholder-10.html placeholder-10.html
-fails == placeholder-11.html placeholder-11.html
-fails == placeholder-12.html placeholder-12.html
+fails needs-focus asserts-if(stylo,1) == placeholder-10.html placeholder-10.html # bug 1324671
+fails asserts-if(stylo,1) == placeholder-11.html placeholder-11.html # bug 1324671
+fails asserts-if(stylo,1) == placeholder-12.html placeholder-12.html # bug 1324671
 fails == placeholder-13.html placeholder-13.html
 fails == placeholder-14.html placeholder-14.html
-fails == placeholder-18.html placeholder-18.html
+fails asserts-if(stylo,1) == placeholder-18.html placeholder-18.html # bug 1324671
 random-if(winWidget) == placeholder-19.xul placeholder-19.xul
 # needs-focus == placeholder-20.html placeholder-20.html
 # needs-focus == placeholder-21.html placeholder-21.html
-fails needs-focus == placeholder-22.html placeholder-22.html
+fails asserts-if(stylo,1) needs-focus == placeholder-22.html placeholder-22.html # bug 1324671
 # == placeholder-rtl.html placeholder-rtl.html
-fails pref(dom.placeholder.show_on_focus,false) needs-focus == placeholder-focus-pref.html placeholder-focus-pref.html
+fails pref(dom.placeholder.show_on_focus,false) asserts-if(stylo,1) needs-focus == placeholder-focus-pref.html placeholder-focus-pref.html # bug 1324671
diff --git a/layout/reftests/forms/progress/reftest-stylo.list b/layout/reftests/forms/progress/reftest-stylo.list
index 579dc823d7ec..0f7e8a46094e 100644
--- a/layout/reftests/forms/progress/reftest-stylo.list
+++ b/layout/reftests/forms/progress/reftest-stylo.list
@@ -28,7 +28,7 @@
 
 # Tests for block and inline orientation in combination with writing-mode
 # == progress-orient-horizontal.html progress-orient-horizontal.html
-fails-if(!cocoaWidget||OSX==1010) == progress-orient-vertical.html progress-orient-vertical.html
+fails-if(!cocoaWidget||OSX==1010) asserts-if(stylo,1) == progress-orient-vertical.html progress-orient-vertical.html # bug 1324671
 # == progress-orient-block.html progress-orient-block.html
 # == progress-orient-inline.html progress-orient-inline.html
 # == progress-vlr.html progress-vlr.html
diff --git a/layout/reftests/scoped-style/reftest-stylo.list b/layout/reftests/scoped-style/reftest-stylo.list
index d319a2ea5d10..3cbcc9e90fa0 100644
--- a/layout/reftests/scoped-style/reftest-stylo.list
+++ b/layout/reftests/scoped-style/reftest-stylo.list
@@ -34,12 +34,12 @@ fails == scoped-style-dynamic-001.html scoped-style-dynamic-001.html
 fails == scoped-style-dynamic-002.html scoped-style-dynamic-002.html
 fails == scoped-style-dynamic-003.html scoped-style-dynamic-003.html
 fails == scoped-style-dynamic-004.html scoped-style-dynamic-004.html
-== scoped-style-dynamic-005.html scoped-style-dynamic-005.html
-fails == scoped-style-dynamic-006.html scoped-style-dynamic-006.html
+asserts-if(stylo,1) == scoped-style-dynamic-005.html scoped-style-dynamic-005.html # bug 1335340
+fails asserts-if(stylo,1) == scoped-style-dynamic-006.html scoped-style-dynamic-006.html # bug 1335340
 fails == scoped-style-dynamic-007.html scoped-style-dynamic-007.html
 fails == scoped-style-dynamic-008.html scoped-style-dynamic-008.html
-fails == scoped-style-dynamic-009.html scoped-style-dynamic-009.html
-== scoped-style-dynamic-010.html scoped-style-dynamic-010.html
+fails asserts-if(stylo,1) == scoped-style-dynamic-009.html scoped-style-dynamic-009.html # bug 1335340
+asserts-if(stylo,1) == scoped-style-dynamic-010.html scoped-style-dynamic-010.html # bug 1335340
 fails == scoped-style-dynamic-011.html scoped-style-dynamic-011.html
 == scoped-style-dynamic-012.svg scoped-style-dynamic-012.svg
 == scoped-style-dynamic-013.svg scoped-style-dynamic-013.svg
diff --git a/layout/reftests/selection/reftest-stylo.list b/layout/reftests/selection/reftest-stylo.list
index 9f1fd5a09e37..4231f7a0ecf2 100644
--- a/layout/reftests/selection/reftest-stylo.list
+++ b/layout/reftests/selection/reftest-stylo.list
@@ -33,6 +33,6 @@ fails == themed-widget.html themed-widget.html
 == addrange-1.html addrange-1.html
 == addrange-2.html addrange-2.html
 fails == splitText-normalize.html splitText-normalize.html
-fails == modify-range.html modify-range.html
+fails asserts-if(stylo,13) == modify-range.html modify-range.html # bug 1324683
 fails == dom-mutations.html dom-mutations.html
 == trailing-space-1.html trailing-space-1.html
diff --git a/layout/reftests/table-bordercollapse/reftest-stylo.list b/layout/reftests/table-bordercollapse/reftest-stylo.list
index 9cf961ef522e..dcac51148088 100644
--- a/layout/reftests/table-bordercollapse/reftest-stylo.list
+++ b/layout/reftests/table-bordercollapse/reftest-stylo.list
@@ -16,9 +16,9 @@
 == bc_dyn_cg1.html bc_dyn_cg1.html
 == bc_dyn_cg2.html bc_dyn_cg2.html
 == bc_dyn_cg3.html bc_dyn_cg3.html
-fails == bc_dyn_table1.html bc_dyn_table1.html
-fails == bc_dyn_table2.html bc_dyn_table2.html
-fails == bc_dyn_table3.html bc_dyn_table3.html
+fails asserts-if(stylo,2) == bc_dyn_table1.html bc_dyn_table1.html # bug 1324661
+fails asserts-if(stylo,2) == bc_dyn_table2.html bc_dyn_table2.html # bug 1324661
+fails asserts-if(stylo,2) == bc_dyn_table3.html bc_dyn_table3.html # bug 1324661
 == bc_borderoffset1.html bc_borderoffset1.html
 == bc_borderoffset2.html bc_borderoffset2.html
 == frame_above_rules_all.html frame_above_rules_all.html
diff --git a/layout/reftests/text-overflow/reftest-stylo.list b/layout/reftests/text-overflow/reftest-stylo.list
index b4a4cb7aa37e..183906a45fb2 100644
--- a/layout/reftests/text-overflow/reftest-stylo.list
+++ b/layout/reftests/text-overflow/reftest-stylo.list
@@ -6,7 +6,7 @@ fails HTTP(..) == marker-string.html marker-string.html
 # == bidi-simple.html bidi-simple.html
 fails == bidi-simple-scrolled.html bidi-simple-scrolled.html
 fails == scroll-rounding.html scroll-rounding.html
-fuzzy(2,453) fuzzy-if(skiaContent,9,2100) fails-if(gtkWidget) HTTP(..) == anonymous-block.html anonymous-block.html
+fuzzy(2,453) fuzzy-if(skiaContent,9,2100) fails-if(gtkWidget) asserts-if(stylo,4) HTTP(..) == anonymous-block.html anonymous-block.html # bug 1324671
 fails HTTP(..) == false-marker-overlap.html false-marker-overlap.html
 fails HTTP(..) == visibility-hidden.html visibility-hidden.html
 # == block-padding.html block-padding.html
diff --git a/layout/reftests/web-animations/reftest-stylo.list b/layout/reftests/web-animations/reftest-stylo.list
index 9542e6404cb8..89dc0109b12d 100644
--- a/layout/reftests/web-animations/reftest-stylo.list
+++ b/layout/reftests/web-animations/reftest-stylo.list
@@ -1,7 +1,7 @@
 # DO NOT EDIT! This is a auto-generated temporary list for Stylo testing
 test-pref(dom.animations-api.core.enabled,true) == 1246046-1.html 1246046-1.html
 test-pref(dom.animations-api.core.enabled,true) == 1267937-1.html 1267937-1.html
-fails test-pref(dom.animations-api.core.enabled,true) == 1298742-1.html 1298742-1.html
+fails test-pref(dom.animations-api.core.enabled,true) asserts-if(stylo,8) == 1298742-1.html 1298742-1.html # bug 1335342
 fails test-pref(dom.animations-api.core.enabled,true) == stacking-context-transform-none-animation-before-appending-element.html stacking-context-transform-none-animation-before-appending-element.html
 # test-pref(dom.animations-api.core.enabled,true) == stacking-context-opacity-changing-keyframe.html stacking-context-opacity-changing-keyframe.html
 # test-pref(dom.animations-api.core.enabled,true) == stacking-context-opacity-changing-keyframe-in-delay.html stacking-context-opacity-changing-keyframe-in-delay.html
diff --git a/layout/reftests/writing-mode/reftest-stylo.list b/layout/reftests/writing-mode/reftest-stylo.list
index 25c97476c540..42fe64f0cbe7 100644
--- a/layout/reftests/writing-mode/reftest-stylo.list
+++ b/layout/reftests/writing-mode/reftest-stylo.list
@@ -16,8 +16,8 @@ fails == 1083848-3-inline-background-repeat.html 1083848-3-inline-background-rep
 # == 1090159-1.html 1090159-1.html
 # == 1090168-1.html 1090168-1.html
 # == 1090168-1.html 1090168-1.html
-fails == 1090168-2.html 1090168-2.html
-fails == 1090168-3.html 1090168-3.html
+fails asserts-if(stylo,1) == 1090168-2.html 1090168-2.html # bug 1324700
+fails asserts-if(stylo,1) == 1090168-3.html 1090168-3.html # bug 1324700
 # == 1091058-1.html 1091058-1.html
 fails == 1094434-1.html 1094434-1.html
 fails == 1094434-2.html 1094434-2.html
@@ -69,7 +69,7 @@ fails == ua-style-sheet-size-2.html ua-style-sheet-size-2.html
 # == ua-style-sheet-checkbox-radio-1.html ua-style-sheet-checkbox-radio-1.html
 # == ua-style-sheet-button-1.html ua-style-sheet-button-1.html
 # == ua-style-sheet-button-1.html ua-style-sheet-button-1.html
-fails == ua-style-sheet-input-color-1.html ua-style-sheet-input-color-1.html
+fails asserts-if(stylo,6) == ua-style-sheet-input-color-1.html ua-style-sheet-input-color-1.html # bug 1324671
 # fuzzy-if(gtkWidget,1,15) == ua-style-sheet-input-number-1.html ua-style-sheet-input-number-1.html
 
 # HTTP(..) == 1127488-align-default-horizontal-tb-ltr.html 1127488-align-default-horizontal-tb-ltr.html
diff --git a/layout/reftests/writing-mode/tables/reftest-stylo.list b/layout/reftests/writing-mode/tables/reftest-stylo.list
index a46f40315a79..9cf06977ec32 100644
--- a/layout/reftests/writing-mode/tables/reftest-stylo.list
+++ b/layout/reftests/writing-mode/tables/reftest-stylo.list
@@ -8,7 +8,7 @@
 == vertical-table-colspan-1.html vertical-table-colspan-1.html
 == vertical-table-colspan-2.html vertical-table-colspan-2.html
 == vertical-table-specified-width-1.html vertical-table-specified-width-1.html
-asserts(1) == vertical-table-specified-width-2.html vertical-table-specified-width-2.html
+asserts(1-2) == vertical-table-specified-width-2.html vertical-table-specified-width-2.html
 == vertical-border-collapse-1.html vertical-border-collapse-1.html
 == vertical-border-collapse-2.html vertical-border-collapse-2.html
 
diff --git a/layout/style/crashtests/crashtests.list b/layout/style/crashtests/crashtests.list
index 31d68e9835cf..b358087cf703 100644
--- a/layout/style/crashtests/crashtests.list
+++ b/layout/style/crashtests/crashtests.list
@@ -76,7 +76,7 @@ load 621596-1.html
 load 622314-1.xhtml
 load 637242.xhtml
 load 645142.html
-fails-if(stylo) asserts-if(stylo,3-4) == 645951-1.html 645951-1-ref.html # bug 1324621
+fails-if(stylo) == 645951-1.html 645951-1-ref.html
 load 652976-1.svg
 load 665209-1.html
 load 671799-1.html
@@ -84,7 +84,7 @@ load 671799-2.html
 skip-if(stylo) load 690990-1.html # bug 1323708
 load 696188-1.html
 load 696869-1.html
-asserts-if(stylo,4) load 700116.html # bug 1324635
+asserts-if(stylo,2) load 700116.html # bug 1324635
 load 729126-1.html
 load 729126-2.html
 load 786108-1.html
@@ -154,8 +154,8 @@ pref(layout.css.background-clip-text.enabled,true) load 1275026.html
 load 1278463-1.html
 skip-if(stylo) pref(dom.animations-api.core.enabled,true) load 1277908-1.html # bug 1323652
 skip-if(stylo) load 1277908-2.html # bug 1323652
-asserts-if(stylo,2-62) load 1282076-1.html # bug 1324669
-asserts-if(stylo,2) pref(dom.animations-api.core.enabled,true) load 1282076-2.html # bug 1324686
+load 1282076-1.html
+pref(dom.animations-api.core.enabled,true) load 1282076-2.html
 pref(dom.animations-api.core.enabled,true) load 1290994-1.html
 pref(dom.animations-api.core.enabled,true) load 1290994-2.html
 pref(dom.animations-api.core.enabled,true) load 1290994-3.html
@@ -165,7 +165,7 @@ load 1315889-1.html
 load 1315894-1.html
 skip-if(stylo) load 1319072-1.html # bug 1323733
 HTTP load 1320423-1.html
-asserts-if(stylo,5-28) load 1321357-1.html # bug 1324669
+load 1321357-1.html
 load 1328535-1.html
 load 1331272.html
-asserts-if(stylo,4) HTTP load 1333001-1.html
+asserts-if(stylo,1) HTTP load 1333001-1.html # bug 1324702
diff --git a/layout/svg/crashtests/crashtests.list b/layout/svg/crashtests/crashtests.list
index 4fd1cdc746a5..bd07ad6d8ce7 100644
--- a/layout/svg/crashtests/crashtests.list
+++ b/layout/svg/crashtests/crashtests.list
@@ -20,34 +20,34 @@ load 327711-1.svg
 load 328137-1.svg
 load 329848-1.svg
 load 337408-1.xul
-asserts-if(stylo,2) load 338301-1.xhtml # bug 1324669
-asserts-if(stylo,2) load 338312-1.xhtml # bug 1324669
+load 338301-1.xhtml
+load 338312-1.xhtml
 load 340083-1.svg
 asserts-if(stylo,1) load 340945-1.svg # bug 1324647
 load 342923-1.html
-asserts-if(stylo,2) load 343221-1.xhtml # bug 1324669
+load 343221-1.xhtml
 load 344749-1.svg
 load 344887-1.svg
 load 344892-1.svg
 load 344898-1.svg
 load 344904-1.svg
 load 345418-1.svg
-asserts-if(stylo,2) load 348982-1.xhtml # bug 1324669
-asserts-if(stylo,1) load 354777-1.xhtml # bug 1324669
+load 348982-1.xhtml
+load 354777-1.xhtml
 load 359516-1.svg
 load 361015-1.svg
 asserts-if(stylo,0-2) load 361587-1.svg # bug 1324677
-asserts-if(stylo,2) load 363611-1.xhtml # bug 1324669
+load 363611-1.xhtml
 load 364688-1.svg
 load 366956-1.svg
 load 366956-2.svg
 load 367111-1.svg
-asserts-if(stylo,2) load 367368-1.xhtml # bug 1324669
+load 367368-1.xhtml
 load 369233-1.svg
 load 369438-1.svg
 load 369438-2.svg
-asserts-if(stylo,2) load 371463-1.xhtml # bug 1324669
-asserts-if(stylo,2) load 371563-1.xhtml # bug 1324669
+load 371463-1.xhtml
+load 371563-1.xhtml
 load 375775-1.svg
 load 378716.svg
 load 380691-1.svg
@@ -61,13 +61,13 @@ load 385552-1.svg
 load 385552-2.svg
 load 385840-1.svg
 load 385852-1.svg
-asserts-if(stylo,2) load 386475-1.xhtml # bug 1324669
+load 386475-1.xhtml
 load 386566-1.svg
 load 386690-1.svg
 load 387290-1.svg
 load 402408-1.svg
-asserts-if(stylo,2) load 404677-1.xhtml # bug 1324669
-asserts-if(stylo,2) load 409565-1.xhtml # bug 1324669
+load 404677-1.xhtml
+load 409565-1.xhtml
 load 409573-1.svg
 load 420697-1.svg
 load 420697-2.svg
@@ -106,7 +106,7 @@ load 590291-1.svg
 load 601999-1.html
 load 605626-1.svg
 asserts(2) asserts-if(stylo,0) load 606914.xhtml # bug 606914
-asserts-if(stylo,2) load 610594-1.html # bug 1324669
+load 610594-1.html
 load 610954-1.html
 load 612662-1.svg
 load 612662-2.svg
@@ -139,13 +139,13 @@ load 757704-1.svg
 load 757718-1.svg
 load 757751-1.svg
 load 767056-1.svg
-asserts-if(stylo,3) load 767535-1.xhtml # bug 1324669
-asserts-if(stylo,1-2) load 768087-1.html # bug 1324669
+load 767535-1.xhtml
+load 768087-1.html
 load 768351.svg
 load 778492-1.svg
 load 779971-1.svg
 load 780764-1.svg
-asserts-if(stylo,2) load 780963-1.html # bug 1324669
+load 780963-1.html
 load 782141-1.svg
 load 784061-1.svg
 load 788831-1.svg
@@ -181,7 +181,7 @@ load 897342-1.svg
 load 898909-1.svg
 load 898951-1.svg
 load 913990.html
-asserts-if(stylo,2) load 919371-1.xhtml # bug 1324669
+load 919371-1.xhtml
 load 950324-1.svg
 load 952270-1.svg
 load 963086-1.svg
@@ -195,7 +195,7 @@ load 1028512.svg
 load 1140080-1.svg
 load 1149542-1.svg
 load 1156581-1.svg
-asserts-if(stylo,1) load 1182496-1.html # bug 1324669
+load 1182496-1.html
 load 1209525-1.svg
 load 1223281-1.svg
 load extref-test-1.xhtml
diff --git a/parser/htmlparser/tests/crashtests/crashtests.list b/parser/htmlparser/tests/crashtests/crashtests.list
index 2d8a3002973c..9e4b389eabd6 100644
--- a/parser/htmlparser/tests/crashtests/crashtests.list
+++ b/parser/htmlparser/tests/crashtests/crashtests.list
@@ -45,7 +45,7 @@ load 525229-1.html
 load 536097-1.html
 load 555462.html
 load 563514-1.html
-asserts-if(stylo,2) load 574884-1.html # bug 1324669
+load 574884-1.html
 load 574884-2.html
 load 591330-1.html
 load 650501-1.xhtml
diff --git a/parser/htmlparser/tests/reftest/reftest-stylo.list b/parser/htmlparser/tests/reftest/reftest-stylo.list
index e50ed9d36c99..5f590dc40fae 100644
--- a/parser/htmlparser/tests/reftest/reftest-stylo.list
+++ b/parser/htmlparser/tests/reftest/reftest-stylo.list
@@ -1,6 +1,6 @@
 # DO NOT EDIT! This is a auto-generated temporary list for Stylo testing
 == bug535530-1.html bug535530-1.html
-fails == view-source:bug535530-2.html view-source:bug535530-2.html
+fails asserts-if(stylo,15) == view-source:bug535530-2.html view-source:bug535530-2.html # bug 1335312
 == bug566280-1.html bug566280-1.html
 == bug569229-1.xml bug569229-1.xml
 fails == bug577418-1.html bug577418-1.html
@@ -8,20 +8,20 @@ fails == bug577418-1.html bug577418-1.html
 fails == bug582940-1.html bug582940-1.html
 == bug592656-1.html bug592656-1.html
 fails == bug599320-1.html bug599320-1.html
-== bug608373-1.html bug608373-1.html
-fails == view-source:bug482921-1.html view-source:bug482921-1.html
-fails == view-source:bug482921-2.xhtml view-source:bug482921-2.xhtml
+asserts-if(stylo,1) == bug608373-1.html bug608373-1.html # bug 1324683
+fails asserts-if(stylo,25) == view-source:bug482921-1.html view-source:bug482921-1.html # bug 1324704
+fails asserts-if(stylo,26) == view-source:bug482921-2.xhtml view-source:bug482921-2.xhtml # bug 1324704
 == bug659763-1.html bug659763-1.html
 == bug659763-2.html bug659763-2.html
 == bug659763-3.html bug659763-3.html
 == bug659763-4.html bug659763-4.html
 == bug659763-5.html bug659763-5.html
 == bug659763-6.html bug659763-6.html
-fails == view-source:bug673094-1.html view-source:bug673094-1.html
+fails asserts-if(stylo,10) == view-source:bug673094-1.html view-source:bug673094-1.html # bug 1324704
 == bug696651-1.html bug696651-1.html
 == bug696651-2.html bug696651-2.html
-fails == view-source:bug700260-1.html view-source:bug700260-1.html
-fails == view-source:bug704667-1.html view-source:bug704667-1.html
-fails == view-source:bug731234-1.html view-source:bug731234-1.html
+fails asserts-if(stylo,4) == view-source:bug700260-1.html view-source:bug700260-1.html # bug 1324704
+fails asserts-if(stylo,2) == view-source:bug704667-1.html view-source:bug704667-1.html # bug 1324704
+fails asserts-if(stylo,28) == view-source:bug731234-1.html view-source:bug731234-1.html # bug 1324704
 == bug820508-1.html bug820508-1.html
-fails == view-source:bug910588-1.html view-source:bug910588-1.html
+fails asserts-if(stylo,2) == view-source:bug910588-1.html view-source:bug910588-1.html # bug 1324704
diff --git a/taskcluster/ci/build/linux.yml b/taskcluster/ci/build/linux.yml
index 145d5af37d07..b8d209e2e0ba 100644
--- a/taskcluster/ci/build/linux.yml
+++ b/taskcluster/ci/build/linux.yml
@@ -348,3 +348,29 @@ linux64-ccov/opt:
         custom-build-variant-cfg: code-coverage
         tooltool-downloads: public
         need-xvfb: true
+
+linux64-add-on-devel/opt:
+    description: "Linux64 add-on-devel"
+    index:
+        product: firefox
+        job-name: linux64-add-on-devel
+    treeherder:
+        platform: linux64-add-on-devel/opt
+        symbol: tc(B)
+        tier: 2
+    worker-type: aws-provisioner-v1/gecko-{level}-b-linux
+    worker:
+        implementation: docker-worker
+        max-run-time: 36000
+    run:
+        using: mozharness
+        actions: [get-secrets build check-test generate-build-stats update]
+        config:
+            - builds/releng_base_linux_64_builds.py
+            - balrog/production.py
+        script: "mozharness/scripts/fx_desktop_build.py"
+        secrets: true
+        custom-build-variant-cfg: add-on-devel
+        tooltool-downloads: public
+        need-xvfb: true
+    run-on-projects: [ 'mozilla-beta', 'mozilla-release', 'mozilla-esr45' ]
diff --git a/taskcluster/taskgraph/transforms/gecko_v2_whitelist.py b/taskcluster/taskgraph/transforms/gecko_v2_whitelist.py
index bbf0049adc4c..24a337d22e49 100644
--- a/taskcluster/taskgraph/transforms/gecko_v2_whitelist.py
+++ b/taskcluster/taskgraph/transforms/gecko_v2_whitelist.py
@@ -51,6 +51,7 @@ JOB_NAME_WHITELIST = set([
     'linux32-nightly-opt',
     'linux32-l10n-opt',
     'linux32-nightly-l10n-opt',
+    'linux64-add-on-devel',
     'macosx64-clang-tidy',
     'macosx64-debug',
     'macosx64-opt',
diff --git a/toolkit/components/telemetry/Histograms.json b/toolkit/components/telemetry/Histograms.json
index 6eb8100bf868..72734878512e 100644
--- a/toolkit/components/telemetry/Histograms.json
+++ b/toolkit/components/telemetry/Histograms.json
@@ -10721,5 +10721,29 @@
     "n_buckets": 10,
     "bug_numbers": [1331804],
     "description": "The time a given main thread runnable took to run (in milliseconds). The key comes from the runnables nsINamed::name value."
+  },
+  "MOZ_BLOB_IN_XHR": {
+    "alert_emails": ["amarchesini@mozilla.com"],
+    "expires_in_version": "58",
+    "kind": "boolean",
+    "bug_numbers": [1335365],
+    "releaseChannelCollection": "opt-out",
+    "description": "XMLHttpRequest.responseType set to moz-blob"
+  },
+  "MOZ_CHUNKED_TEXT_IN_XHR": {
+    "alert_emails": ["amarchesini@mozilla.com"],
+    "expires_in_version": "58",
+    "kind": "boolean",
+    "bug_numbers": [1335365],
+    "releaseChannelCollection": "opt-out",
+    "description": "XMLHttpRequest.responseType set to moz-chunked-text"
+  },
+  "MOZ_CHUNKED_ARRAYBUFFER_IN_XHR": {
+    "alert_emails": ["amarchesini@mozilla.com"],
+    "expires_in_version": "58",
+    "kind": "boolean",
+    "bug_numbers": [1335365],
+    "releaseChannelCollection": "opt-out",
+    "description": "XMLHttpRequest.responseType set to moz-chunked-arraybuffer"
   }
 }
diff --git a/toolkit/components/telemetry/TelemetryScalar.cpp b/toolkit/components/telemetry/TelemetryScalar.cpp
index 58bf61c2fabb..fb8589b49acd 100644
--- a/toolkit/components/telemetry/TelemetryScalar.cpp
+++ b/toolkit/components/telemetry/TelemetryScalar.cpp
@@ -94,6 +94,7 @@ enum class ScalarResult : uint8_t {
   InvalidType,
   InvalidValue,
   // Keyed Scalar Errors
+  KeyIsEmpty,
   KeyTooLong,
   TooManyKeys,
   // String Scalar Errors
@@ -693,6 +694,10 @@ KeyedScalar::GetValue(nsTArray<KeyValuePair>& aValues) const
 ScalarResult
 KeyedScalar::GetScalarForKey(const nsAString& aKey, ScalarBase** aRet)
 {
+  if (aKey.IsEmpty()) {
+    return ScalarResult::KeyIsEmpty;
+  }
+
   if (aKey.Length() >= kMaximumKeyStringLength) {
     return ScalarResult::KeyTooLong;
   }
@@ -821,6 +826,9 @@ internal_LogScalarError(const nsACString& aScalarName, ScalarResult aSr)
     case ScalarResult::StringTooLong:
       errorMessage.Append(NS_LITERAL_STRING(" - Truncating scalar value to 50 characters."));
       break;
+    case ScalarResult::KeyIsEmpty:
+      errorMessage.Append(NS_LITERAL_STRING(" - The key must not be empty."));
+      break;
     case ScalarResult::KeyTooLong:
       errorMessage.Append(NS_LITERAL_STRING(" - The key length must be limited to 70 characters."));
       break;
diff --git a/toolkit/components/telemetry/TelemetrySession.jsm b/toolkit/components/telemetry/TelemetrySession.jsm
index 2dd9169b1128..933ec80beb36 100644
--- a/toolkit/components/telemetry/TelemetrySession.jsm
+++ b/toolkit/components/telemetry/TelemetrySession.jsm
@@ -734,8 +734,6 @@ var Impl = {
    * @return simple measurements as a dictionary.
    */
   getSimpleMeasurements: function getSimpleMeasurements(forSavedSession, isSubsession, clearSubsession) {
-    this._log.trace("getSimpleMeasurements");
-
     let si = Services.startup.getStartupInfo();
 
     // Measurements common to chrome and content processes.
@@ -889,9 +887,6 @@ var Impl = {
   },
 
   getHistograms: function getHistograms(subsession, clearSubsession) {
-    this._log.trace("getHistograms - subsession: " + subsession +
-                    ", clearSubsession: " + clearSubsession);
-
     let registered =
       Telemetry.registeredHistograms(this.getDatasetType(), []);
     if (this._testing == false) {
@@ -919,8 +914,6 @@ var Impl = {
   },
 
   getAddonHistograms: function getAddonHistograms() {
-    this._log.trace("getAddonHistograms");
-
     let ahs = Telemetry.addonHistogramSnapshots;
     let ret = {};
 
@@ -938,9 +931,6 @@ var Impl = {
   },
 
   getKeyedHistograms(subsession, clearSubsession) {
-    this._log.trace("getKeyedHistograms - subsession: " + subsession +
-                    ", clearSubsession: " + clearSubsession);
-
     let registered =
       Telemetry.registeredKeyedHistograms(this.getDatasetType(), []);
     if (this._testing == false) {
@@ -989,9 +979,6 @@ var Impl = {
    *            {'content': { 'scalarName': ... }, 'gpu': { ... } }
    */
   getScalars(subsession, clearSubsession, keyed) {
-    this._log.trace("getScalars - subsession: " + subsession + ", clearSubsession: " +
-                    clearSubsession + ", keyed: " + keyed);
-
     if (!subsession) {
       // We only support scalars for subsessions.
       this._log.trace("getScalars - We only support scalars in subsessions.");
@@ -1007,7 +994,6 @@ var Impl = {
     for (let processName in scalarsSnapshot) {
       for (let name in scalarsSnapshot[processName]) {
         if (name.startsWith("telemetry.test") && this._testing == false) {
-          this._log.trace("getScalars - Skipping test scalar: " + name);
           continue;
         }
         // Finally arrange the data in the returned object.
@@ -1040,8 +1026,6 @@ var Impl = {
   },
 
   getThreadHangStats: function getThreadHangStats(stats) {
-    this._log.trace("getThreadHangStats");
-
     stats.forEach((thread) => {
       thread.activity = this.packHistogram(thread.activity);
       thread.hangs.forEach((hang) => {
@@ -1060,8 +1044,6 @@ var Impl = {
    * @return The metadata as a JS object
    */
   getMetadata: function getMetadata(reason) {
-    this._log.trace("getMetadata - Reason " + reason);
-
     const sessionStartDate = Utils.toLocalTimeISOString(Utils.truncateToDays(this._sessionStartDate));
     const subsessionStartDate = Utils.toLocalTimeISOString(Utils.truncateToDays(this._subsessionStartDate));
     const monotonicNow = Policy.monotonicNow();
@@ -1112,12 +1094,9 @@ var Impl = {
    */
   gatherMemory: function gatherMemory() {
     if (!Telemetry.canRecordExtended) {
-      this._log.trace("gatherMemory - Extended data recording disabled, skipping.");
       return;
     }
 
-    this._log.trace("gatherMemory");
-
     let mgr;
     try {
       mgr = Cc["@mozilla.org/memory-reporter-manager;1"].
@@ -1610,7 +1589,6 @@ var Impl = {
   },
 
   getFlashVersion: function getFlashVersion() {
-    this._log.trace("getFlashVersion");
     let host = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
     let tags = host.getPluginTags();
 
@@ -1780,8 +1758,7 @@ var Impl = {
   },
 
 
-  testSavePendingPing: function testSaveHistograms() {
-    this._log.trace("testSaveHistograms");
+  testSavePendingPing() {
     let payload = this.getSessionPayload(REASON_SAVED_SESSION, false);
     let options = {
       addClientId: true,
diff --git a/toolkit/components/telemetry/TelemetryStorage.jsm b/toolkit/components/telemetry/TelemetryStorage.jsm
index 14a86ad09cb9..1f31af32e11c 100644
--- a/toolkit/components/telemetry/TelemetryStorage.jsm
+++ b/toolkit/components/telemetry/TelemetryStorage.jsm
@@ -690,8 +690,6 @@ var TelemetryStorageImpl = {
    * @return {promise<object>} Promise that is resolved with the ping data.
    */
   loadArchivedPing: Task.async(function*(id) {
-    this._log.trace("loadArchivedPing - id: " + id);
-
     const data = this._archivedPings.get(id);
     if (!data) {
       this._log.trace("loadArchivedPing - no ping with id: " + id);
@@ -1733,7 +1731,6 @@ var TelemetryStorageImpl = {
   }),
 
   isDeletionPing(aPingId) {
-    this._log.trace("isDeletionPing - id: " + aPingId);
     let pingInfo = this._pendingPings.get(aPingId);
     if (!pingInfo) {
       return false;
diff --git a/toolkit/components/telemetry/tests/unit/test_TelemetryScalars.js b/toolkit/components/telemetry/tests/unit/test_TelemetryScalars.js
index 15cd60a0f666..d0da88e2a4fb 100644
--- a/toolkit/components/telemetry/tests/unit/test_TelemetryScalars.js
+++ b/toolkit/components/telemetry/tests/unit/test_TelemetryScalars.js
@@ -473,6 +473,9 @@ add_task(function* test_keyed_keys_length() {
   Telemetry.keyedScalarSet(KEYED_UINT_SCALAR, LONG_KEY_STRING, 1);
   Telemetry.keyedScalarSetMaximum(KEYED_UINT_SCALAR, LONG_KEY_STRING, 10);
 
+  // Also attempt to set the value for an empty key.
+  Telemetry.keyedScalarSet(KEYED_UINT_SCALAR, "", 1);
+
   // Make sure the key with the right length contains the expected value.
   let keyedScalars =
     getParentProcessScalars(Ci.nsITelemetry.DATASET_RELEASE_CHANNEL_OPTIN, true);
@@ -484,6 +487,8 @@ add_task(function* test_keyed_keys_length() {
                "The key must contain the expected value.");
   Assert.ok(!(LONG_KEY_STRING in keyedScalars[KEYED_UINT_SCALAR]),
             "The data for the long key should not have been recorded.");
+  Assert.ok(!("" in keyedScalars[KEYED_UINT_SCALAR]),
+            "The data for the empty key should not have been recorded.");
 });
 
 add_task(function* test_keyed_max_keys() {