Use DEFINE_NODE_TYPE_CASTS instead of using manual toHTMLFooElement()

Source/core/html/HTMLObjectElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2008, 2009 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 96 matching lines @@
     virtual HTMLFormElement* virtualForm() const;
 
     virtual bool shouldRegisterAsNamedItem() const OVERRIDE { return isDocNamedItem(); }
     virtual bool shouldRegisterAsExtraNamedItem() const OVERRIDE { return isDocNamedItem(); }
 
     String m_classId;
     bool m_docNamedItem : 1;
     bool m_useFallbackContent : 1;
 };
 
-inline HTMLObjectElement* toHTMLObjectElement(Node* node)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!node || node->hasTagName(HTMLNames::objectTag));
-    return static_cast<HTMLObjectElement*>(node);
-}
+DEFINE_NODE_TYPE_CASTS(HTMLObjectElement, hasTagName(HTMLNames::objectTag));
 
 inline const HTMLObjectElement* toHTMLObjectElement(const FormAssociatedElement* element)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!element || !element->isFormControlElement());
     const HTMLObjectElement* objectElement = static_cast<const HTMLObjectElement*>(element);
     // We need to assert after the cast because FormAssociatedElement doesn't
     // have hasTagName.
     ASSERT_WITH_SECURITY_IMPLICATION(!objectElement || objectElement->hasTagName(HTMLNames::objectTag));
     return objectElement;
 }
 
 }
 
 #endif