cc: Remove FakeThread, use SingleThreadTaskRunner in scheduling classes.

cc/base/thread.h

 // 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.
 
 #ifndef CC_BASE_THREAD_H_
 #define CC_BASE_THREAD_H_
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/time.h"
 #include "cc/base/cc_export.h"
 
+namespace base { class SingleThreadTaskRunner; }
+
 namespace cc {
 
 // Thread provides basic infrastructure for messaging with the compositor in a
 // platform-neutral way.
 class CC_EXPORT Thread {
  public:
   virtual ~Thread() {}
 
   // Executes the callback on context's thread asynchronously.
   virtual void PostTask(base::Closure cb) = 0;
 
   // Executes the task after the specified delay.
   virtual void PostDelayedTask(base::Closure cb, base::TimeDelta delay) = 0;
 
   virtual bool BelongsToCurrentThread() const = 0;
+
+  virtual base::SingleThreadTaskRunner* TaskRunner() = 0;
 };
 
 }  // namespace cc
 
 #endif  // CC_BASE_THREAD_H_