TaskGraphRunner refactor

components/mus/gles2/raster_thread_helper.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_MUS_GLES2_RASTER_THREAD_HELPER_H_
 #define COMPONENTS_MUS_GLES2_RASTER_THREAD_HELPER_H_
 
 #include "base/memory/scoped_ptr.h"
 
 namespace cc {
 class TaskGraphRunner;
+class SingleThreadTaskGraphRunner;
 }
 
 namespace gles2 {
 
 class RasterThreadHelper {
  public:
   RasterThreadHelper();
   ~RasterThreadHelper();
 
-  cc::TaskGraphRunner* task_graph_runner() { return task_graph_runner_.get(); }
+  cc::TaskGraphRunner* task_graph_runner();
 
  private:
-  class RasterThread;
-
-  scoped_ptr<cc::TaskGraphRunner> task_graph_runner_;
-  scoped_ptr<RasterThread> raster_thread_;
+  scoped_ptr<cc::SingleThreadTaskGraphRunner> task_graph_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(RasterThreadHelper);
 };
 
 }  // namespace gles2
 
 #endif  // COMPONENTS_MUS_GLES2_RASTER_THREAD_HELPER_H_