Change cc::ElementId to be a uint64_t

cc/animation/animation_host.h

 // Copyright 2015 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_ANIMATION_HOST_H_
 #define CC_ANIMATION_ANIMATION_HOST_H_
 
 #include <memory>
 #include <unordered_map>
 #include <vector>
@@ skipping 29 matching lines @@
 // There is just one AnimationHost for LayerTreeHost on main renderer thread
 // and just one AnimationHost for LayerTreeHostImpl on impl thread.
 // We synchronize them during the commit process in a one-way data flow process
 // (PushPropertiesTo).
 // An AnimationHost talks to its correspondent LayerTreeHost via
 // MutatorHostClient interface.
 class CC_ANIMATION_EXPORT AnimationHost
     : public NON_EXPORTED_BASE(MutatorHost) {
  public:
   using ElementToAnimationsMap =
-      std::unordered_map<ElementId,
-                         scoped_refptr<ElementAnimations>,
-                         ElementIdHash>;
+      std::unordered_map<ElementId::Id, scoped_refptr<ElementAnimations>>;

[wkorman, 2017/05/08 18:23:24]

My personal preference given our shift to support pdr@ pitch re: type safety,
and balancing readability/maintenance, would be to not leak ElementId::Id
outside of the class itself and just use ElementId and add operators / hash
funcs if needed. But I am ok trying it this way if we'd like.

   using PlayersList = std::vector<scoped_refptr<AnimationPlayer>>;
 
   static std::unique_ptr<AnimationHost> CreateMainInstance();
   static std::unique_ptr<AnimationHost> CreateForTesting(
       ThreadInstance thread_instance);
   ~AnimationHost() override;
 
   void AddAnimationTimeline(scoped_refptr<AnimationTimeline> timeline);
   void RemoveAnimationTimeline(scoped_refptr<AnimationTimeline> timeline);
   AnimationTimeline* GetTimelineById(int timeline_id) const;
@@ skipping 145 matching lines @@
 
   bool supports_scroll_animations_;
   bool needs_push_properties_;
 
   DISALLOW_COPY_AND_ASSIGN(AnimationHost);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_ANIMATION_HOST_H_