cc: Use Element Id to Record Animation Changes

cc/layers/layer.h

Index: cc/layers/layer.h
diff --git a/cc/layers/layer.h b/cc/layers/layer.h
index faee6ac7fd98bf6f17226aec8aca96dc130e9474..9ecbe42e6d01959cd50f65c95ad1a75aa1f8b210 100644
--- a/cc/layers/layer.h
+++ b/cc/layers/layer.h
@@ -501,9 +501,6 @@ class CC_EXPORT Layer : public base::RefCounted<Layer> {
   void OnTransformAnimated(const gfx::Transform& transform);
   void OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset);
 
-  void OnIsAnimatingChanged(const PropertyAnimationState& mask,
-                            const PropertyAnimationState& state);
-
   bool FilterIsAnimating() const;
   bool TransformIsAnimating() const;
   bool ScrollOffsetAnimationWasInterrupted() const;