Add more missing closing namespace comments.

third_party/WebKit/Source/core/html/ImageDocument.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 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 442 matching lines @@
     }
 }
 
 bool ImageEventListener::operator==(const EventListener& listener) const
 {
     if (const ImageEventListener* imageEventListener = ImageEventListener::cast(&listener))
         return m_doc == imageEventListener->m_doc;
     return false;
 }
 
-}
+} // namespace blink