Clean forward declaration in public

public/platform/WebURLLoadTiming.h

 /*
  * Copyright (C) 2010 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 19 matching lines @@
 
 #ifndef WebURLLoadTiming_h
 #define WebURLLoadTiming_h
 
 #include "WebCommon.h"
 #include "WebPrivatePtr.h"
 
 namespace blink {
 
 class ResourceLoadTiming;
-class WebString;
 
 class WebURLLoadTiming {
 public:
     ~WebURLLoadTiming() { reset(); }
 
     WebURLLoadTiming() { }
     WebURLLoadTiming(const WebURLLoadTiming& d) { assign(d); }
     WebURLLoadTiming& operator=(const WebURLLoadTiming& d)
     {
         assign(d);
@@ skipping 57 matching lines @@
     BLINK_PLATFORM_EXPORT operator WTF::PassRefPtr<ResourceLoadTiming>() const;
 #endif
 
 private:
     WebPrivatePtr<ResourceLoadTiming> m_private;
 };
 
 } // namespace blink
 
 #endif