Make Element::elementData() / ensureUniqueElementData() protected

Source/core/css/resolver/SharedStyleFinder.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 98 matching lines @@
 }
 
 static inline const AtomicString& typeAttributeValue(const Element& element)
 {
     // type is animatable in SVG so we need to go down the slow path here.
     return element.isSVGElement() ? element.getAttribute(typeAttr) : element.fastGetAttribute(typeAttr);
 }
 
 bool SharedStyleFinder::sharingCandidateHasIdenticalStyleAffectingAttributes(Element& candidate) const
 {
-    if (element().elementData() == candidate.elementData())
+    if (element().sharesSameElementData(candidate))
         return true;
     if (element().fastGetAttribute(XMLNames::langAttr) != candidate.fastGetAttribute(XMLNames::langAttr))
         return false;
     if (element().fastGetAttribute(langAttr) != candidate.fastGetAttribute(langAttr))
         return false;
 
     // These two checks must be here since RuleSet has a special case to allow style sharing between elements
     // with type and readonly attributes whereas other attribute selectors prevent sharing.
     if (typeAttributeValue(element()) != typeAttributeValue(candidate))
         return false;
@@ skipping 207 matching lines @@
     // Tracking child index requires unique style for each node. This may get set by the sibling rule match above.
     if (!element().parentElementOrShadowRoot()->childrenSupportStyleSharing()) {
         INCREMENT_STYLE_STATS_COUNTER(m_styleResolver, sharedStyleRejectedByParent);
         return 0;
     }
 
     return shareElement->renderStyle();
 }
 
 }