Replace elementHasLegalLinkAttribute() helper with virtual function

Source/core/html/HTMLFormElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 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 109 matching lines @@
 
     virtual bool rendererIsNeeded(const RenderStyle&) OVERRIDE;
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
     virtual void removedFrom(ContainerNode*) OVERRIDE;
     virtual void finishParsingChildren() OVERRIDE;
 
     virtual void handleLocalEvents(Event*) OVERRIDE;
 
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual bool isURLAttribute(const Attribute&) const OVERRIDE;
+    virtual bool hasLegalLinkAttribute(const QualifiedName&) const OVERRIDE;
 
     virtual bool shouldRegisterAsNamedItem() const OVERRIDE { return true; }
 
     virtual void copyNonAttributePropertiesFromElement(const Element&) OVERRIDE;
 
     void submitDialog(PassRefPtr<FormSubmission>);
     void submit(Event*, bool activateSubmitButton, bool processingUserGesture, FormSubmissionTrigger);
 
     void scheduleFormSubmission(PassRefPtr<FormSubmission>);
 
@@ skipping 39 matching lines @@
 
     void requestAutocompleteTimerFired(Timer<HTMLFormElement>*);
 
     Vector<RefPtr<Event> > m_pendingAutocompleteEvents;
     Timer<HTMLFormElement> m_requestAutocompleteTimer;
 };
 
 } // namespace WebCore
 
 #endif // HTMLFormElement_h