Revert of Use element id's for animations

ui/compositor/layer.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.h"
 
 #include <algorithm>
 #include <memory>
 #include <utility>
 
@@ skipping 494 matching lines @@
 
   for (size_t i = 0; i < children_.size(); ++i) {
     DCHECK(children_[i]->cc_layer_);
     cc_layer_->AddChild(children_[i]->cc_layer_);
   }
   cc_layer_->SetLayerClient(this);
   cc_layer_->SetTransformOrigin(gfx::Point3F());
   cc_layer_->SetContentsOpaque(fills_bounds_opaquely_);
   cc_layer_->SetIsDrawable(type_ != LAYER_NOT_DRAWN);
   cc_layer_->SetHideLayerAndSubtree(!visible_);
-  cc_layer_->SetElementId(cc::ElementId(cc_layer_->id(), 0));
 
   SetLayerFilters();
   SetLayerBackgroundFilters();
 }
 
 bool Layer::HasPendingThreadedAnimationsForTesting() const {
   return animator_->HasPendingThreadedAnimationsForTesting();
 }
 
 void Layer::SwitchCCLayerForTest() {
@@ skipping 456 matching lines @@
     nine_patch_layer_ = cc::NinePatchLayer::Create();
     cc_layer_ = nine_patch_layer_.get();
   } else {
     content_layer_ = cc::PictureLayer::Create(this);
     cc_layer_ = content_layer_.get();
   }
   cc_layer_->SetTransformOrigin(gfx::Point3F());
   cc_layer_->SetContentsOpaque(true);
   cc_layer_->SetIsDrawable(type_ != LAYER_NOT_DRAWN);
   cc_layer_->SetLayerClient(this);
-  cc_layer_->SetElementId(cc::ElementId(cc_layer_->id(), 0));
   RecomputePosition();
 }
 
 gfx::Transform Layer::transform() const {
   return cc_layer_->transform();
 }
 
 void Layer::RecomputeDrawsContentAndUVRect() {
   DCHECK(cc_layer_);
   gfx::Size size(bounds_.size());
@@ skipping 48 matching lines @@
   if (animator_) {
     animator_->ResetCompositor(compositor);
     animator_->RemoveFromCollection(collection);
   }
 
   for (auto* child : children_)
     child->ResetCompositorForAnimatorsInTree(compositor);
 }
 
 }  // namespace ui