Add more missing closing namespace comments.

third_party/WebKit/Source/core/page/DragClient.h

 /*
  * Copyright (C) 2007 Apple 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:
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 26 matching lines @@
 class LocalFrame;
 class IntPoint;
 
 class DragClient {
 public:
     virtual DragDestinationAction actionMaskForDrag(DragData*) = 0;
     virtual void startDrag(DragImage*, const IntPoint& dragImageOrigin, const IntPoint& eventPos, DataTransfer*, LocalFrame*, bool linkDrag = false) = 0;
     virtual ~DragClient() { }
 };
 
-}
+} // namespace blink
 
 #endif // !DragClient_h