cc : Track transform animation changes on transform tree

cc/layers/layer.h

Index: cc/layers/layer.h
diff --git a/cc/layers/layer.h b/cc/layers/layer.h
index f39dfe1efc8d2faaf1413a1dfc7178e65f771fb6..36a5019a4a56a8c4ad4671364f86f0b342dfd9de 100644
--- a/cc/layers/layer.h
+++ b/cc/layers/layer.h
@@ -495,6 +495,7 @@ class CC_EXPORT Layer : public base::RefCounted<Layer> {
   void OnOpacityAnimated(float opacity);
   void OnTransformAnimated(const gfx::Transform& transform);
   void OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset);
+  void OnTransformIsCurrentlyAnimatingChanged(bool is_animating);
   void OnTransformIsPotentiallyAnimatingChanged(bool is_animating);
   void OnOpacityIsCurrentlyAnimatingChanged(bool is_currently_animating);
   void OnOpacityIsPotentiallyAnimatingChanged(bool has_potential_animation);