Replace elementHasLegalLinkAttribute() helper with virtual function

Source/core/html/HTMLModElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2003, 2006, 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.
@@ skipping 27 matching lines @@
 PassRefPtr<HTMLModElement> HTMLModElement::create(const QualifiedName& tagName, Document& document)
 {
     return adoptRef(new HTMLModElement(tagName, document));
 }
 
 bool HTMLModElement::isURLAttribute(const Attribute& attribute) const
 {
     return attribute.name() == citeAttr || HTMLElement::isURLAttribute(attribute);
 }
 
+bool HTMLModElement::hasLegalLinkAttribute(const QualifiedName& name) const
+{
+    return name == citeAttr || HTMLElement::hasLegalLinkAttribute(name);
 }
+
+}