Add more missing closing namespace comments.

third_party/WebKit/Source/core/dom/DOMNodeIds.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/dom/DOMNodeIds.h"
 
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
@@ skipping 16 matching lines @@
 {
     return WeakIdentifierMap<Node>::identifier(node);
 }
 
 // static
 Node* DOMNodeIds::nodeForId(int id)
 {
     return WeakIdentifierMap<Node>::lookup(id);
 }
 
-}
+} // namespace blink