Clean forward declaration in public

public/web/WebPlugin.h

 /*
  * Copyright (C) 2009, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2014 Opera Software ASA. 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.
@@ skipping 27 matching lines @@
 #include "WebDragOperation.h"
 #include "WebDragStatus.h"
 #include "WebWidget.h"
 #include <v8.h>
 
 struct NPObject;
 struct _NPP;
 
 namespace blink {
 
-class WebDataSource;
 class WebDragData;
 class WebInputEvent;
 class WebPluginContainer;
 class WebURLResponse;
 struct WebCompositionUnderline;
 struct WebCursorInfo;
-struct WebPluginParams;
 struct WebPrintParams;
 struct WebPrintPresetOptions;
 struct WebPoint;
 struct WebRect;
-struct WebTextInputInfo;
 struct WebURLError;
 template <typename T> class WebVector;
 
 class WebPlugin {
 public:
     virtual bool initialize(WebPluginContainer*) = 0;
     virtual void destroy() = 0;
 
     virtual WebPluginContainer* container() const { return 0; }
     virtual void containerDidDetachFromParent() { }
@@ skipping 110 matching lines @@
     virtual bool isPlaceholder() { return true; }
     virtual bool shouldPersist() const { return false; }
 
 protected:
     ~WebPlugin() { }
 };
 
 } // namespace blink
 
 #endif