Move MessageLoop to base namespace.

media/base/pipeline.h

 // Copyright (c) 2012 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 MEDIA_BASE_PIPELINE_H_
 #define MEDIA_BASE_PIPELINE_H_
 
 #include <string>
 
 #include "base/gtest_prod_util.h"
 #include "base/synchronization/condition_variable.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/default_clock.h"
 #include "media/base/audio_renderer.h"
 #include "media/base/demuxer.h"
 #include "media/base/media_export.h"
 #include "media/base/pipeline_status.h"
 #include "media/base/ranges.h"
 #include "media/base/serial_runner.h"
 #include "ui/gfx/size.h"
 
-class MessageLoop;
-
 namespace base {
 class MessageLoopProxy;
 class TimeDelta;
 }
 
 namespace media {
 
 class Clock;
 class FilterCollection;
 class MediaLog;
@@ skipping 440 matching lines @@
   scoped_ptr<SerialRunner> pending_callbacks_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(Pipeline);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_PIPELINE_H_