Clean forward declaration in public

public/web/WebDevToolsAgentClient.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 20 matching lines @@
 #ifndef WebDevToolsAgentClient_h
 #define WebDevToolsAgentClient_h
 
 #include "../platform/WebCString.h"
 #include "../platform/WebCommon.h"
 
 namespace blink {
 
 class WebString;
 struct WebDeviceEmulationParams;
-struct WebDevToolsMessageData;
-struct WebRect;
-struct WebSize;
 
 class WebDevToolsAgentClient {
 public:
     virtual void sendMessageToInspectorFrontend(const WebString&) { }
     virtual void sendDebuggerOutput(const WebString&) { }
 
     // Returns process id.
     virtual long processId() { return -1; }
 
     // Returns unique identifier of the entity within process.
@@ skipping 34 matching lines @@
     // Cancel emulation started via |enableDeviceEmulation| call.
     virtual void disableDeviceEmulation() { }
 
 protected:
     ~WebDevToolsAgentClient() { }
 };
 
 } // namespace blink
 
 #endif