cc: LayerTreeHostImpl uses element id to tick animations

cc/layers/scrollbar_layer_unittest.cc

 // 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.
 
 #include <stddef.h>
 
 #include <unordered_map>
 
 #include "base/memory/ptr_util.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 610 matching lines @@
   node = layer_tree_impl->property_trees()->effect_tree.Node(
       scrollbar_layer->effect_tree_index());
   EXPECT_EQ(node->opacity, 0.f);
   host_impl->ActivateSyncTree();
   layer_tree_impl = host_impl->active_tree();
   node = layer_tree_impl->property_trees()->effect_tree.Node(
       scrollbar_layer->effect_tree_index());
   EXPECT_EQ(node->opacity, 0.f);
 
   // This tests that activation does not change the opacity of scrollbar layer.
-  LayerImpl* scrollbar_layer_impl =
-      layer_tree_impl->LayerById(scrollbar_layer->id());
-  layer_tree_impl->property_trees()->effect_tree.OnOpacityAnimated(
-      0.25f, scrollbar_layer_impl->effect_tree_index(), layer_tree_impl);
+  ScrollbarLayerImplBase* scrollbar_layer_impl =
+      static_cast<ScrollbarLayerImplBase*>(
+          layer_tree_impl->LayerById(scrollbar_layer->id()));
+  scrollbar_layer_impl->SetOverlayScrollbarLayerOpacityAnimated(0.25f);
   host_impl->CreatePendingTree();
   layer_impl_tree_root = layer_tree_host_->CommitAndCreatePendingTree();
   layer_tree_impl = layer_impl_tree_root->layer_tree_impl();
   EXPECT_TRUE(layer_tree_impl->IsPendingTree());
   node = layer_tree_impl->property_trees()->effect_tree.Node(
       scrollbar_layer->effect_tree_index());
   EXPECT_EQ(node->opacity, 0.f);
   host_impl->ActivateSyncTree();
   layer_tree_impl = host_impl->active_tree();
   node = layer_tree_impl->property_trees()->effect_tree.Node(
@@ skipping 522 matching lines @@
   TestScale(gfx::Rect(1240, 0, 15, 1333), 2.7754839f);
   TestScale(gfx::Rect(1240, 0, 15, 677), 2.46677136f);
 
   // Horizontal Scrollbars.
   TestScale(gfx::Rect(0, 1240, 1333, 15), 2.7754839f);
   TestScale(gfx::Rect(0, 1240, 677, 15), 2.46677136f);
 }
 
 }  // namespace
 }  // namespace cc