Reduce forward declarations in core/rendering

Source/core/rendering/RenderEmbeddedObject.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef RenderEmbeddedObject_h
 #define RenderEmbeddedObject_h
 
 #include "core/rendering/RenderPart.h"
 
 namespace WebCore {
 
-class MouseEvent;
 class TextRun;
 
 // Renderer for embeds and objects, often, but not always, rendered via plug-ins.
 // For example, <embed src="foo.html"> does not invoke a plug-in.
 class RenderEmbeddedObject : public RenderPart {
 public:
     RenderEmbeddedObject(Element*);
     virtual ~RenderEmbeddedObject();
 
     enum PluginUnavailabilityReason {
@@ skipping 29 matching lines @@
     bool m_showsUnavailablePluginIndicator;
     PluginUnavailabilityReason m_pluginUnavailabilityReason;
     String m_unavailablePluginReplacementText;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderEmbeddedObject, isEmbeddedObject());
 
 } // namespace WebCore
 
 #endif // RenderEmbeddedObject_h