Web Animations: Allow animations with delay to start on compositor

Source/core/rendering/RenderBox.h

Index: Source/core/rendering/RenderBox.h
diff --git a/Source/core/rendering/RenderBox.h b/Source/core/rendering/RenderBox.h
index 112c7b1adb4d5c6a11eb98baea69757766dd36dd..6f61fdfce516fd28cdb8cfb8e4b438d25164adc2 100644
--- a/Source/core/rendering/RenderBox.h
+++ b/Source/core/rendering/RenderBox.h
@@ -23,6 +23,7 @@
 #ifndef RenderBox_h
 #define RenderBox_h
 
+#include "core/animation/ActiveAnimations.h"
 #include "core/rendering/RenderBoxModelObject.h"
 #include "core/rendering/RenderOverflow.h"
 #include "core/rendering/shapes/ShapeOutsideInfo.h"
@@ -71,7 +72,7 @@ public:
     // position:static elements that are not flex-items get their z-index coerced to auto.
     virtual LayerType layerTypeRequired() const OVERRIDE
     {
-        if (isRoot() || isPositioned() || createsGroup() || hasClipPath() || hasTransform() || hasHiddenBackface() || hasReflection() || style()->specifiesColumns() || !style()->hasAutoZIndex() || style()->hasWillChangeCompositingHint())
+        if (isRoot() || isPositioned() || createsGroup() || hasClipPath() || hasTransform() || hasHiddenBackface() || hasReflection() || style()->specifiesColumns() || !style()->hasAutoZIndex() || style()->hasWillChangeCompositingHint() || shouldCompositeForActiveAnimations(*this))

[Julien - ping for review, 2014/03/10 18:11:59]

Note that other renderers override this (e.g. RenderTableRow, RenderInline,
RenderBoxModelObject, ...) and they would need to be updated too.

[dstockwell, 2014/03/11 03:21:30]

Added. Looked at all the overrides, seems to be just the ones you listed that
are necessary.

             return NormalLayer;
         if (hasOverflowClip())
             return OverflowClipLayer;