CC Animation: Use std::bitset to update animation state.

cc/trees/layer_tree.h

Index: cc/trees/layer_tree.h
diff --git a/cc/trees/layer_tree.h b/cc/trees/layer_tree.h
index 9df09e6264ac5c2893c1daf1e43e01a381ca9c9c..1039e77b480440bdb748701fd30064d7b135f7a5 100644
--- a/cc/trees/layer_tree.h
+++ b/cc/trees/layer_tree.h
@@ -227,18 +227,12 @@ class CC_EXPORT LayerTree : public MutatorHostClient {
       ElementId element_id,
       ElementListType list_type,
       const gfx::ScrollOffset& scroll_offset) override;
-  void ElementTransformIsAnimatingChanged(ElementId element_id,
-                                          ElementListType list_type,
-                                          AnimationChangeType change_type,
-                                          bool is_animating) override;
-  void ElementOpacityIsAnimatingChanged(ElementId element_id,
-                                        ElementListType list_type,
-                                        AnimationChangeType change_type,
-                                        bool is_animating) override;
-  void ElementFilterIsAnimatingChanged(ElementId element_id,
-                                       ElementListType list_type,
-                                       AnimationChangeType change_type,
-                                       bool is_animating) override;
+
+  void ElementIsAnimatingChanged(ElementId element_id,
+                                 ElementListType list_type,
+                                 const PropertyAnimationState& mask,
+                                 const PropertyAnimationState& state) override;
+
   void ScrollOffsetAnimationFinished() override {}
   gfx::ScrollOffset GetScrollOffsetForAnimation(
       ElementId element_id) const override;