Clean forward declaration in public

public/web/WebPermissionClient.h

 /*
  * Copyright (C) 2011 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 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WebPermissionClient_h
 #define WebPermissionClient_h
 
 #include "public/platform/WebPermissionCallbacks.h"
 
 namespace blink {
 
-class WebDocument;
 class WebSecurityOrigin;
 class WebString;
 class WebURL;
 
 class WebPermissionClient {
 public:
     // Controls whether access to Web Databases is allowed for this frame.
     virtual bool allowDatabase(const WebString& name, const WebString& displayName, unsigned long estimatedSize) { return true; }
 
     // Controls whether access to File System is allowed for this frame.
@@ skipping 65 matching lines @@
     // Notifies the client that the frame would have executed script if script were enabled.
     virtual void didNotAllowScript() { }
 
 protected:
     ~WebPermissionClient() { }
 };
 
 } // namespace blink
 
 #endif