Refactor MutatorHostClient from LayerTreeHost to LayerTree.

cc/trees/tree_synchronizer_unittest.cc

 // Copyright 2011 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/trees/tree_synchronizer.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <set>
@@ skipping 65 matching lines @@
   explicit MockLayer(std::vector<int>* layer_impl_destruction_list)
       : layer_impl_destruction_list_(layer_impl_destruction_list) {}
   ~MockLayer() override {}
 
   std::vector<int>* layer_impl_destruction_list_;
 };
 
 void ExpectTreesAreIdentical(Layer* root_layer,
                              LayerImpl* root_layer_impl,
                              LayerTreeImpl* tree_impl) {
-  auto layer_iter = root_layer->layer_tree_host()->begin();
+  auto layer_iter = root_layer->GetLayerTree()->begin();
   auto layer_impl_iter = tree_impl->begin();
-  for (; layer_iter != root_layer->layer_tree_host()->end();
+  for (; layer_iter != root_layer->GetLayerTree()->end();
        ++layer_iter, ++layer_impl_iter) {
     Layer* layer = *layer_iter;
     LayerImpl* layer_impl = *layer_impl_iter;
     ASSERT_TRUE(layer);
     ASSERT_TRUE(layer_impl);
 
     EXPECT_EQ(layer->id(), layer_impl->id());
     EXPECT_EQ(layer_impl->layer_tree_impl(), tree_impl);
 
     EXPECT_EQ(layer->non_fast_scrollable_region(),
@@ skipping 600 matching lines @@
   host_->CommitAndCreatePendingTree();
   host_impl->ActivateSyncTree();
   EXPECT_EQ(
       CombinedAnimationScale(0.f, 0.f),
       host_impl->active_tree()->property_trees()->GetAnimationScales(
           transform_layer->transform_tree_index(), host_impl->active_tree()));
 }
 
 }  // namespace
 }  // namespace cc