Replace elementHasLegalLinkAttribute() helper with virtual function

Source/core/html/HTMLTableElement.cpp

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2008, 2010, 2011 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
@@ skipping 518 matching lines @@
     }
     DEFINE_STATIC_REF(StylePropertySet, columnBorderStyle, (createGroupBorderStyle(false)));
     return columnBorderStyle;
 }
 
 bool HTMLTableElement::isURLAttribute(const Attribute& attribute) const
 {
     return attribute.name() == backgroundAttr || HTMLElement::isURLAttribute(attribute);
 }
 
+bool HTMLTableElement::hasLegalLinkAttribute(const QualifiedName& name) const
+{
+    return name == backgroundAttr || HTMLElement::hasLegalLinkAttribute(name);
+}
+
 PassRefPtr<HTMLCollection> HTMLTableElement::rows()
 {
     return ensureCachedHTMLCollection(TableRows);
 }
 
 PassRefPtr<HTMLCollection> HTMLTableElement::tBodies()
 {
     return ensureCachedHTMLCollection(TableTBodies);
 }
 
 const AtomicString& HTMLTableElement::rules() const
 {
     return getAttribute(rulesAttr);
 }
 
 const AtomicString& HTMLTableElement::summary() const
 {
     return getAttribute(summaryAttr);
 }
 
 }