Add more missing closing namespace comments.

third_party/WebKit/Source/core/xml/XPathNodeSet.cpp

 /*
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  *
  * 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 260 matching lines @@
 }
 
 Node* NodeSet::anyNode() const
 {
     if (isEmpty())
         return nullptr;
 
     return m_nodes.at(0).get();
 }
 
-}
-}
+} // namespace XPath
+} // namespace blink