TaskGraphRunner refactor

cc/test/layer_tree_test.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/test/layer_tree_test.h"
 
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/thread_task_runner_handle.h"
@@ skipping 1132 matching lines @@
   // Source frames start at 0, so this is invalid.
   return -1;
 }
 
 void LayerTreeTest::DestroyLayerTreeHost() {
   if (layer_tree_host_ && layer_tree_host_->root_layer())
     layer_tree_host_->root_layer()->SetLayerTreeHost(NULL);
   layer_tree_host_ = nullptr;
 }
 
+TaskGraphRunner* LayerTreeTest::task_graph_runner() const {
+  return task_graph_runner_.get();
+}
+
 LayerTreeHost* LayerTreeTest::layer_tree_host() {
   // We check for a null task_runner_provider here as we sometimes ask for the
   // layer tree host when the task_runner_provider does not exist, often for
   // checking settings after a test has completed. For example,
   // LTHPixelResourceTest::RunPixelResourceTest. See elsewhere in this file for
   // other examples.
   DCHECK(!task_runner_provider() || task_runner_provider()->IsMainThread() ||
          task_runner_provider()->IsMainThreadBlocked());
   return layer_tree_host_.get();
 }
 
 }  // namespace cc