Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

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.
  *
@@ skipping 70 matching lines @@
     virtual const RenderObjectChildList* virtualChildren() const OVERRIDE FINAL { return children(); }
 
     bool m_hasFallbackContent; // FIXME: This belongs on HTMLObjectElement.
 
     bool m_showsUnavailablePluginIndicator;
     PluginUnavailabilityReason m_pluginUnavailabilityReason;
     String m_unavailablePluginReplacementText;
     RenderObjectChildList m_children;
 };
 
-inline RenderEmbeddedObject* toRenderEmbeddedObject(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isEmbeddedObject());
-    return static_cast<RenderEmbeddedObject*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toRenderEmbeddedObject(const RenderEmbeddedObject*);
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderEmbeddedObject, isEmbeddedObject());
 
 } // namespace WebCore
 
 #endif // RenderEmbeddedObject_h