Add more missing closing namespace comments.

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

 /*
  * Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 130 matching lines @@
 }
 
 bool HTMLSummaryElement::willRespondToMouseClickEvents()
 {
     if (isMainSummary() && layoutObject())
         return true;
 
     return HTMLElement::willRespondToMouseClickEvents();
 }
 
-}
+} // namespace blink