Add missing closing namespace comments to wtf.

third_party/WebKit/Source/wtf/TreeNode.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 179 matching lines @@
         return 0;
 
     typename TreeNode<T>::NodeType* next = current->next();
     if (!next)
         return current->parent();
     while (next->firstChild())
         next = next->firstChild();
     return next;
 }
 
-}
+} // namespace WTF
 
 using WTF::TreeNode;
 using WTF::traverseNext;
 using WTF::traverseNextPostOrder;
 
 #endif