Make WeakPtr use SequenceChecker instead of ThreadChecker

webkit/media/webmediaplayer_ms.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 WEBKIT_MEDIA_WEBMEDIAPLAYER_MS_H_
 #define WEBKIT_MEDIA_WEBMEDIAPLAYER_MS_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
+#include "base/threading/thread_checker.h"
 #include "googleurl/src/gurl.h"
 #include "media/filters/skcanvas_video_renderer.h"
 #include "skia/ext/platform_canvas.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebMediaPlayer.h"
 
 namespace WebKit {
 class WebFrame;
 class WebMediaPlayerClient;
 class WebVideoFrame;
 }
@@ skipping 154 matching lines @@
   // Used to auto mute the local media streams when getting the first
   // SetVolume() from WebMediaPlayer.
   bool volume_modified_;
 
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerMS);
 };
 
 }  // namespace webkit_media
 
 #endif  // WEBKIT_MEDIA_WEBMEDIAPLAYER_MS_H_