Refactor MutatorHostClient from LayerTreeHost to LayerTree.

cc/trees/layer_tree_host_common_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/layer_tree_host_common.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 4853 matching lines @@
   scoped_refptr<Layer> replica_layer = Layer::Create();
 
   grand_child->SetReplicaLayer(replica_layer.get());
   child->AddChild(grand_child.get());
   child->SetMaskLayer(mask_layer.get());
   root->AddChild(child.get());
 
   host()->SetRootLayer(root);
 
   int nonexistent_id = -1;
-  EXPECT_EQ(root.get(), host()->LayerById(root->id()));
-  EXPECT_EQ(child.get(), host()->LayerById(child->id()));
-  EXPECT_EQ(grand_child.get(), host()->LayerById(grand_child->id()));
-  EXPECT_EQ(mask_layer.get(), host()->LayerById(mask_layer->id()));
-  EXPECT_EQ(replica_layer.get(), host()->LayerById(replica_layer->id()));
-  EXPECT_FALSE(host()->LayerById(nonexistent_id));
+  LayerTree* layer_tree = host()->GetLayerTree();
+  EXPECT_EQ(root.get(), layer_tree->LayerById(root->id()));
+  EXPECT_EQ(child.get(), layer_tree->LayerById(child->id()));
+  EXPECT_EQ(grand_child.get(), layer_tree->LayerById(grand_child->id()));
+  EXPECT_EQ(mask_layer.get(), layer_tree->LayerById(mask_layer->id()));
+  EXPECT_EQ(replica_layer.get(), layer_tree->LayerById(replica_layer->id()));
+  EXPECT_FALSE(layer_tree->LayerById(nonexistent_id));
 }
 
 TEST_F(LayerTreeHostCommonTest, TransparentChildRenderSurfaceCreation) {
   LayerImpl* root = root_layer_for_testing();
   LayerImpl* child = AddChild<LayerImpl>(root);
   LayerImpl* grand_child = AddChild<LayerImpl>(child);
 
   root->SetBounds(gfx::Size(100, 100));
   child->SetBounds(gfx::Size(10, 10));
   child->test_properties()->opacity = 0.5f;
@@ skipping 4822 matching lines @@
   EXPECT_EQ(scroll_child6.id, grand_child10->scroll_tree_index());
   EXPECT_EQ(scroll_root1.id, parent3->scroll_tree_index());
   EXPECT_EQ(scroll_child7.id, child8->scroll_tree_index());
   EXPECT_EQ(scroll_root1.id, parent4->scroll_tree_index());
   EXPECT_EQ(scroll_root1.id, child9->scroll_tree_index());
   EXPECT_EQ(scroll_root1.id, grand_child12->scroll_tree_index());
 }
 
 }  // namespace
 }  // namespace cc