CC Animation: Use bitset instead of unordered_set in LayerAnimationController

cc/animation/layer_animation_controller.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_ANIMATION_LAYER_ANIMATION_CONTROLLER_H_
 #define CC_ANIMATION_LAYER_ANIMATION_CONTROLLER_H_
 
-#include <unordered_set>
+#include <bitset>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/time/time.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/layer_animation_event_observer.h"
+#include "cc/animation/target_property.h"
 #include "cc/base/cc_export.h"
 #include "ui/gfx/geometry/scroll_offset.h"
 #include "ui/gfx/transform.h"
 
 namespace gfx {
 class BoxF;
 class Transform;
 }
 
 namespace cc {
@@ skipping 140 matching lines @@
   bool needs_to_start_animations_for_testing() {
     return needs_to_start_animations_;
   }
 
  private:
   friend class base::RefCounted<LayerAnimationController>;
 
   explicit LayerAnimationController(int id);
   ~LayerAnimationController();
 
-  using TargetProperties = std::unordered_set<int>;
+  // A set of target properties. TargetProperty must be 0-based enum.
+  using TargetProperties =
+      std::bitset<TargetProperty::LAST_TARGET_PROPERTY + 1>;
 
   void PushNewAnimationsToImplThread(
       LayerAnimationController* controller_impl) const;
   void MarkAbortedAnimationsForDeletion(
       LayerAnimationController* controller_impl) const;
   void RemoveAnimationsCompletedOnMainThread(
       LayerAnimationController* controller_impl) const;
   void PushPropertiesToImplThread(LayerAnimationController* controller_impl);
 
   void StartAnimations(base::TimeTicks monotonic_time);
@@ skipping 58 matching lines @@
 
   bool potentially_animating_transform_for_active_observers_;
   bool potentially_animating_transform_for_pending_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerAnimationController);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_LAYER_ANIMATION_CONTROLLER_H_