Revert of Use element id's for animations

ui/compositor/layer_animator.cc

 // Copyright (c) 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.
 
 #include "ui/compositor/layer_animator.h"
 
 #include <stddef.h>
 
 #include <memory>
 
@@ skipping 138 matching lines @@
 
   cc::AnimationTimeline* timeline = compositor->GetAnimationTimeline();
   DCHECK(timeline);
 
   DCHECK(delegate_->GetCcLayer());
 
   // Register ElementAnimations so it will be picked up by
   // AnimationHost::RegisterPlayerForLayer via
   // AnimationHost::GetElementAnimationsForLayerId.
   if (element_animations_state_) {
-    DCHECK_EQ(element_animations_state_->element_id().primaryId,
+    DCHECK_EQ(element_animations_state_->element_id(),
               delegate_->GetCcLayer()->id());
     timeline->animation_host()->RegisterElementAnimations(
         element_animations_state_.get());
   }
 
   timeline->AttachPlayer(animation_player_);
 
   AttachLayerToAnimationPlayer(delegate_->GetCcLayer()->id());
 
   // Release ElementAnimations state.
   element_animations_state_ = nullptr;
 }
 
 void LayerAnimator::ResetCompositor(Compositor* compositor) {
   DCHECK(compositor);
 
   cc::AnimationTimeline* timeline = compositor->GetAnimationTimeline();
   DCHECK(timeline);
 
-  cc::ElementId element_id(animation_player_->element_id());
+  const int layer_id = animation_player_->element_id();
 
   // Store a reference to ElementAnimations (if any)
   // so it may be picked up in LayerAnimator::SetCompositor.
-  if (element_id) {
+  if (layer_id) {
     element_animations_state_ =
-        timeline->animation_host()->GetElementAnimationsForElementId(
-            element_id);
+        timeline->animation_host()->GetElementAnimationsForElementId(layer_id);
   }
 
   DetachLayerFromAnimationPlayer();
 
   timeline->DetachPlayer(animation_player_);
 }
 
 void LayerAnimator::AttachLayerToAnimationPlayer(int layer_id) {
-  // For ui, layer and element ids are equivalent.
-  cc::ElementId element_id(layer_id, 0);
   if (!animation_player_->element_id())
-    animation_player_->AttachElement(element_id);
+    animation_player_->AttachElement(layer_id);
   else
-    DCHECK_EQ(animation_player_->element_id(), element_id);
+    DCHECK_EQ(animation_player_->element_id(), layer_id);
 
   animation_player_->set_animation_delegate(this);
 }
 
 void LayerAnimator::DetachLayerFromAnimationPlayer() {
   animation_player_->set_animation_delegate(nullptr);
 
   if (animation_player_->element_id())
     animation_player_->DetachElement();
 }
@@ skipping 756 matching lines @@
     const base::WeakPtr<LayerAnimationSequence>& sequence)
     : sequence_(sequence) {
 }
 
 LayerAnimator::RunningAnimation::RunningAnimation(
     const RunningAnimation& other) = default;
 
 LayerAnimator::RunningAnimation::~RunningAnimation() { }
 
 }  // namespace ui