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

content/renderer/media/android/webmediaplayer_proxy_android.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/android/webmediaplayer_proxy_android.h"
 
 #include "base/bind.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "content/common/media/media_player_messages_android.h"
 #include "content/renderer/media/android/renderer_media_player_manager.h"
 #include "content/renderer/media/android/webmediaplayer_android.h"
 
 namespace content {
 
 WebMediaPlayerProxyAndroid::WebMediaPlayerProxyAndroid(
     RenderView* render_view,
     RendererMediaPlayerManager* manager)
     : RenderViewObserver(render_view), manager_(manager) {}
@@ skipping 277 matching lines @@
     int media_keys_id,
     const std::string& session_id,
     const std::vector<uint8>& message,
     const std::string& destination_url) {
   WebMediaPlayerAndroid* player = GetWebMediaPlayer(media_keys_id);
   if (player)
     player->OnKeyMessage(session_id, message, destination_url);
 }
 
 }  // namespace content