Revert of Use element id's for animations

cc/test/animation_timelines_test_common.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_TEST_ANIMATION_TIMELINES_TEST_COMMON_H_
 #define CC_TEST_ANIMATION_TIMELINES_TEST_COMMON_H_
 
 #include <memory>
 #include <unordered_map>
 
@@ skipping 174 matching lines @@
                                       ElementListType list_type,
                                       int transform_x,
                                       int transform_y) const;
 
   TestLayer* FindTestLayer(ElementId element_id,
                            ElementListType list_type) const;
 
  private:
   std::unique_ptr<AnimationHost> host_;
 
-  using ElementIdToTestLayer =
-      std::unordered_map<ElementId, std::unique_ptr<TestLayer>, ElementIdHash>;
-  ElementIdToTestLayer layers_in_active_tree_;
-  ElementIdToTestLayer layers_in_pending_tree_;
+  using LayerIdToTestLayer =
+      std::unordered_map<int, std::unique_ptr<TestLayer>>;
+  LayerIdToTestLayer layers_in_active_tree_;
+  LayerIdToTestLayer layers_in_pending_tree_;
 
   gfx::ScrollOffset scroll_offset_;
   bool mutators_need_commit_;
 };
 
 class TestAnimationDelegate : public AnimationDelegate {
  public:
   TestAnimationDelegate();
 
   void NotifyAnimationStarted(base::TimeTicks monotonic_time,
@@ skipping 48 matching lines @@
   void CreateTestImplLayer(ElementListType element_list_type);
 
   scoped_refptr<ElementAnimations> element_animations() const;
   scoped_refptr<ElementAnimations> element_animations_impl() const;
 
   void ReleaseRefPtrs();
 
   void AnimateLayersTransferEvents(base::TimeTicks time,
                                    unsigned expect_events);
 
-  AnimationPlayer* GetPlayerForElementId(ElementId element_id);
+  AnimationPlayer* GetPlayerForLayerId(ElementId element_id);
   AnimationPlayer* GetImplPlayerForLayerId(ElementId element_id);
 
   int NextTestLayerId();
 
   TestHostClient client_;
   TestHostClient client_impl_;
 
   AnimationHost* host_;
   AnimationHost* host_impl_;
 
   const int timeline_id_;
   const int player_id_;
-  ElementId element_id_;
+  int element_id_;
 
   int next_test_layer_id_;
 
   scoped_refptr<AnimationTimeline> timeline_;
   scoped_refptr<AnimationPlayer> player_;
 
   scoped_refptr<AnimationTimeline> timeline_impl_;
   scoped_refptr<AnimationPlayer> player_impl_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_ANIMATION_TIMELINES_TEST_COMMON_H_