Use a direct include of the message_loop header in content/, part 4.

content/renderer/media/webmediaplayer_ms.cc

 // Copyright 2013 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 "content/renderer/media/webmediaplayer_ms.h"
 
 #include <limits>
 
 #include "base/bind.h"
 #include "base/callback.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "cc/layers/video_layer.h"
 #include "content/renderer/media/media_stream_audio_renderer.h"
 #include "content/renderer/media/media_stream_client.h"
 #include "content/renderer/media/video_frame_provider.h"
 #include "content/renderer/media/webmediaplayer_delegate.h"
 #include "content/renderer/media/webmediaplayer_util.h"
 #include "media/base/media_log.h"
 #include "media/base/video_frame.h"
 #include "third_party/WebKit/public/platform/WebRect.h"
@@ skipping 411 matching lines @@
   GetClient()->readyStateChanged();
 }
 
 WebKit::WebMediaPlayerClient* WebMediaPlayerMS::GetClient() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(client_);
   return client_;
 }
 
 }  // namespace content