Add more missing closing namespace comments.

third_party/WebKit/Source/modules/mediasource/HTMLVideoElementMediaSource.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 27 matching lines @@
 
 class HTMLVideoElement;
 class VideoPlaybackQuality;
 
 class HTMLVideoElementMediaSource {
     STATIC_ONLY(HTMLVideoElementMediaSource);
 public:
     static VideoPlaybackQuality* getVideoPlaybackQuality(HTMLVideoElement&);
 };
 
-}
+} // namespace blink
 
 #endif