cc: Use property tree index accessors in Layer::On<Property>Animated

cc/layers/layer.cc

 // Copyright 2010 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 "cc/layers/layer.h"
 
 #include <algorithm>
 
 #include "base/atomic_sequence_num.h"
 #include "base/location.h"
@@ skipping 1390 matching lines @@
 // set directly rather than by calling Set<Property>.
 void Layer::OnFilterAnimated(const FilterOperations& filters) {
   filters_ = filters;
 }
 
 void Layer::OnOpacityAnimated(float opacity) {
   opacity_ = opacity;
   if (layer_tree_host_) {
     if (OpacityNode* node =
             layer_tree_host_->property_trees()->opacity_tree.Node(
-                opacity_tree_index_)) {
+                opacity_tree_index())) {
       if (node->owner_id == id())
         node->data = opacity;
     }
   }
 }
 
 void Layer::OnTransformAnimated(const gfx::Transform& transform) {
   if (transform_ == transform)
     return;
   transform_ = transform;
   transform_is_invertible_ = transform.IsInvertible();
   if (layer_tree_host_) {
     if (TransformNode* node =
             layer_tree_host_->property_trees()->transform_tree.Node(
-                transform_tree_index_)) {
+                transform_tree_index())) {
       if (node->owner_id == id()) {
         node->data.local = transform;
         node->data.needs_local_transform_update = true;
         node->data.is_animated = true;
         layer_tree_host_->property_trees()->transform_tree.set_needs_update(
             true);
       }
     }
   }
 }
@@ skipping 132 matching lines @@
 
 void Layer::DidBeginTracing() {
   // We'll be dumping layer trees as part of trace, so make sure
   // PushPropertiesTo() propagates layer debug info to the impl
   // side -- otherwise this won't happen for the the layers that
   // remain unchanged since tracing started.
   SetNeedsPushProperties();
 }
 
 }  // namespace cc