Add more missing closing namespace comments.

third_party/WebKit/Source/core/fetch/DocumentResourceReference.h

 /*
  * Copyright (C) 2012 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:
  *
  * 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 24 matching lines @@
     USING_FAST_MALLOC(DocumentResourceReference);
 public:
     DocumentResourceReference(DocumentResource* document) : m_document(document) { m_document->addClient(this); }
     ~DocumentResourceReference() override { m_document->removeClient(this); }
     DocumentResource* document() { return m_document.get(); }
 private:
     String debugName() const override { return "DocumentResourceReference"; }
     ResourcePtr<DocumentResource> m_document;
 };
 
-};
+} // namespace blink;
 
 #endif