Use a direct include of the message_loop header in media/.

media/audio/audio_output_dispatcher.cc

 // 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.
 
 #include "media/audio/audio_output_dispatcher.h"
 
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 
 namespace media {
 
 AudioOutputDispatcher::AudioOutputDispatcher(
     AudioManager* audio_manager,
     const AudioParameters& params,
     const std::string& input_device_id)
     : audio_manager_(audio_manager),
       message_loop_(base::MessageLoop::current()),
       params_(params),
       input_device_id_(input_device_id) {
   // We expect to be instantiated on the audio thread.  Otherwise the
   // message_loop_ member will point to the wrong message loop!
   DCHECK(audio_manager->GetMessageLoop()->BelongsToCurrentThread());
 }
 
 AudioOutputDispatcher::~AudioOutputDispatcher() {
   DCHECK_EQ(base::MessageLoop::current(), message_loop_);
 }
 
 }  // namespace media