Bug 1343057 - Part 2: Disable AA for layers with animation in effect. r=mattwoodrow

--HG--
extra : rebase_source : 1de5a9f4a4e18ba8624433a43a22b8ac47a9cc91

layout/generic/nsFrame.cpp

@@ -1310,11 +1310,16 @@ nsIFrame::IsTransformed() const
   return ((mState & NS_FRAME_MAY_BE_TRANSFORMED) &&
           (StyleDisplay()->HasTransform(this) ||
            IsSVGTransformed() ||
-           (mContent &&
-            nsLayoutUtils::HasAnimationOfProperty(this,
-                                                  eCSSProperty_transform) &&
-            IsFrameOfType(eSupportsCSSTransforms) &&
-            mContent->GetPrimaryFrame() == this)));
+           HasAnimationOfTransform()));
+}
+
+bool
+nsIFrame::HasAnimationOfTransform() const
+{
+  return mContent &&
+    nsLayoutUtils::HasAnimationOfProperty(this, eCSSProperty_transform) &&
+    IsFrameOfType(eSupportsCSSTransforms) &&
+    mContent->GetPrimaryFrame() == this;
 }
 
 bool

layout/generic/nsIFrame.h

@@ -1641,6 +1641,11 @@ public:
    */
   bool IsTransformed() const;
 
+  /**
+   * True if this frame has any animation of transform in effect.
+   */
+  bool HasAnimationOfTransform() const;
+
   /**
    * Returns true if the frame is translucent or the frame has opacity
    * animations for the purposes of creating a stacking context.

layout/painting/FrameLayerBuilder.cpp

@@ -5541,7 +5541,10 @@ ChooseScaleAndSetTransform(FrameLayerBuilder* aLayerBuilder,
   if ((aLayerBuilder->IsBuildingRetainedLayers() &&
        (!canDraw2D || transform2d.HasNonIntegerTranslation())) ||
       aContainerFrame->Extend3DContext() ||
-      aContainerFrame->Combines3DTransformWithAncestors()) {
+      aContainerFrame->Combines3DTransformWithAncestors() ||
+      // For async transform animation, the value would be changed at
+      // any time, integer translation is not always true.
+      aContainerFrame->HasAnimationOfTransform()) {
     aOutgoingScale.mDisableSubpixelAntialiasingInDescendants = true;
   }
   return true;