Add more missing closing namespace comments.

third_party/WebKit/Source/platform/ContextMenuItem.h

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2010 Igalia S.L
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 73 matching lines @@
 private:
     ContextMenuItemType m_type;
     ContextMenuAction m_action;
     String m_title;
     String m_icon;
     bool m_enabled;
     bool m_checked;
     Vector<ContextMenuItem> m_subMenuItems;
 };
 
-}
+} // namespace blink
 
 #endif // ContextMenuItem_h