Add more missing closing namespace comments.

third_party/WebKit/Source/web/PrerendererClientImpl.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:
  *
  *     * 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 37 matching lines @@
     explicit PrerendererClientImpl(WebPrerendererClient*);
 
     void willAddPrerender(Prerender*) override;
 
     DEFINE_INLINE_VIRTUAL_TRACE() { PrerendererClient::trace(visitor); }
 
 private:
     WebPrerendererClient* m_client;
 };
 
-}
+} // namespace blink
 
 #endif // PrerendererClientImpl_h