cc: Make LayerAnimationController keep state for clearing scroll delta

cc/layers/layer.h

Index: cc/layers/layer.h
diff --git a/cc/layers/layer.h b/cc/layers/layer.h
index 91dbdeede45489e8ec919adeea6a314ec3efddc0..017df68429956cc0065a7b98c9a4a7e713f24979 100644
--- a/cc/layers/layer.h
+++ b/cc/layers/layer.h
@@ -607,7 +607,6 @@ class CC_EXPORT Layer : public base::RefCounted<Layer>,
   void OnTransformAnimated(const gfx::Transform& transform) override;
   void OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset) override;
   void OnAnimationWaitingForDeletion() override;
-  void OnScrollOffsetAnimationRemoved() override;
   bool IsActive() const override;
 
   // If this layer has a scroll parent, it removes |this| from its list of
@@ -660,7 +659,6 @@ class CC_EXPORT Layer : public base::RefCounted<Layer>,
   bool force_render_surface_ : 1;
   bool transform_is_invertible_ : 1;
   bool has_render_surface_ : 1;
-  bool clear_impl_scroll_delta_ : 1;
   Region non_fast_scrollable_region_;
   Region touch_event_handler_region_;
   gfx::PointF position_;