Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/RenderWidget.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2009, 2010 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,
@@ skipping 61 matching lines @@
 
     bool setWidgetGeometry(const LayoutRect&);
     bool updateWidgetGeometry();
 
     RefPtr<Widget> m_widget;
     FrameView* m_frameView;
     IntRect m_clipRect; // The rectangle needs to remain correct after scrolling, so it is stored in content view coordinates, and not clipped to window.
     int m_refCount;
 };
 
-inline RenderWidget* toRenderWidget(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isWidget());
-    return static_cast<RenderWidget*>(object);
-}
-
-inline const RenderWidget* toRenderWidget(const RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isWidget());
-    return static_cast<const RenderWidget*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toRenderWidget(const RenderWidget*);
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderWidget, isWidget());
 
 } // namespace WebCore
 
 #endif // RenderWidget_h