Cleanup: Remove unneeded forward declarations in webkit/plugins/.

webkit/plugins/ppapi/ppb_widget_impl.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WEBKIT_PLUGINS_PPAPI_PPB_WIDGET_IMPL_H_
 #define WEBKIT_PLUGINS_PPAPI_PPB_WIDGET_IMPL_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "ppapi/c/pp_rect.h"
 #include "ppapi/shared_impl/resource.h"
 #include "ppapi/thunk/ppb_widget_api.h"
 
-struct PPB_Widget_Dev;
-
 namespace gfx {
 class Rect;
 }
 namespace ppapi {
 struct InputEventData;
 }
 
 namespace webkit {
 namespace ppapi {
 
@@ skipping 28 matching lines @@
  private:
   PP_Rect location_;
 
   DISALLOW_COPY_AND_ASSIGN(PPB_Widget_Impl);
 };
 
 }  // namespace ppapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_PPAPI_PPB_WIDGET_IMPL_H_