Replace elementHasLegalLinkAttribute() helper with virtual function

Source/core/html/HTMLBodyElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2004, 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.
@@ skipping 35 matching lines @@
 private:
     explicit HTMLBodyElement(Document&);
 
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual bool isPresentationAttribute(const QualifiedName&) const OVERRIDE;
     virtual void collectStyleForPresentationAttribute(const QualifiedName&, const AtomicString&, MutableStylePropertySet*) OVERRIDE;
 
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
 
     virtual bool isURLAttribute(const Attribute&) const OVERRIDE;
+    virtual bool hasLegalLinkAttribute(const QualifiedName&) const OVERRIDE;
 
     virtual bool supportsFocus() const OVERRIDE;
 
     virtual int scrollLeft() OVERRIDE;
     virtual void setScrollLeft(int) OVERRIDE;
 
     virtual int scrollTop() OVERRIDE;
     virtual void setScrollTop(int) OVERRIDE;
 
     virtual int scrollHeight() OVERRIDE;
     virtual int scrollWidth() OVERRIDE;
 };
 
 } //namespace
 
 #endif