Run smooth scroll animations on the compositor when possible

cc/layers/layer.h

Index: cc/layers/layer.h
diff --git a/cc/layers/layer.h b/cc/layers/layer.h
index 06669d31877a4d8fcf8c0da0031c6ae5c241fe9c..0b188ca5b85f542ba0644c4343bd78358691c0d4 100644
--- a/cc/layers/layer.h
+++ b/cc/layers/layer.h
@@ -413,6 +413,7 @@ class CC_EXPORT Layer : public base::RefCounted<Layer>,
   void PauseAnimation(int animation_id, double time_offset);
   void RemoveAnimation(int animation_id);
   void RemoveAnimation(int animation_id, Animation::TargetProperty property);
+  void AbortAnimation(int animation_id);
   LayerAnimationController* layer_animation_controller() const {
     return layer_animation_controller_.get();
   }