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 588e4502e84e88dd2b8dcdfab26c7da13320cc4e..97f316bb0a13cc48d0e4908cc5384e98b630f489 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))
             return NormalLayer;
         if (hasOverflowClip())
             return OverflowClipLayer;