Replace elementHasLegalLinkAttribute() helper with virtual function

Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1032 matching lines @@
     // If there is currently no StyleResolver, we can't be sure that this attribute change won't affect style.
     shouldInvalidateStyle |= !styleResolver;
 
     if (shouldInvalidateStyle)
         setNeedsStyleRecalc(SubtreeStyleChange);
 
     if (AXObjectCache* cache = document().existingAXObjectCache())
         cache->handleAttributeChanged(name, this);
 }
 
+bool Element::hasLegalLinkAttribute(const QualifiedName&) const
+{
+    return false;
+}
+
 inline void Element::attributeChangedFromParserOrByCloning(const QualifiedName& name, const AtomicString& newValue, AttributeModificationReason reason)
 {
     if (name == isAttr)
         CustomElementRegistrationContext::setTypeExtension(this, newValue);
     attributeChanged(name, newValue, reason);
 }
 
 template <typename CharacterType>
 static inline bool classStringHasClassName(const CharacterType* characters, unsigned length)
 {
@@ skipping 2477 matching lines @@
     // Before doing so, we need to resolve issues in HTMLSelectElement::recalcListItems
     // and RenderMenuList::setText. See also https://bugs.webkit.org/show_bug.cgi?id=88405
     if (isHTMLOptionElement(*this) || isHTMLOptGroupElement(*this))
         return false;
     if (FullscreenElementStack::isActiveFullScreenElement(this))
         return false;
     return true;
 }
 
 } // namespace WebCore