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

cc/layers/layer.h

Index: cc/layers/layer.h
diff --git a/cc/layers/layer.h b/cc/layers/layer.h
index 762a56ce96f27fbb9f96bf8afec3103f9169b719..a8f1e07c2a815289f145d791ec043b0e51d73877 100644
--- a/cc/layers/layer.h
+++ b/cc/layers/layer.h
@@ -566,12 +566,9 @@ 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);
-  void OnFilterIsCurrentlyAnimatingChanged(bool is_currently_animating);
-  void OnFilterIsPotentiallyAnimatingChanged(bool has_potential_animation);
+
+  void OnIsAnimatingChanged(const PropertyAnimationState& mask,
+                            const PropertyAnimationState& state);
 
   bool FilterIsAnimating() const;
   bool TransformIsAnimating() const;