Clean forward declaration in public

public/platform/WebData.h

 /*
  * Copyright (C) 2009 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 WebData_h
 #define WebData_h
 
 #include "WebCommon.h"
 #include "WebPrivatePtr.h"
 
 namespace blink {
 
 class SharedBuffer;
-class WebDataPrivate;
 
 // A container for raw bytes.  It is inexpensive to copy a WebData object.
 //
 // WARNING: It is not safe to pass a WebData across threads!!!
 //
 class BLINK_PLATFORM_EXPORT WebData {
 public:
     ~WebData() { reset(); }
 
     WebData() { }
@@ skipping 46 matching lines @@
     }
 #endif
 
 private:
     WebPrivatePtr<SharedBuffer> m_private;
 };
 
 } // namespace blink
 
 #endif