Use new is*Element() helper functions in DOM code

Source/core/dom/VisitedLinkState.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 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 31 matching lines @@
     ASSERT(element.isLink());
     if (element.isHTMLElement())
         return element.fastGetAttribute(HTMLNames::hrefAttr);
     ASSERT(element.isSVGElement());
     return element.getAttribute(XLinkNames::hrefAttr);
 }
 
 static inline LinkHash linkHashForElement(const Element& element, const AtomicString& attribute = AtomicString())
 {
     ASSERT(attribute.isNull() || linkAttribute(element) == attribute);
-    if (element.hasTagName(HTMLNames::aTag))
+    if (isHTMLAnchorElement(element))
         return toHTMLAnchorElement(element).visitedLinkHash();
     return visitedLinkHash(element.document().baseURL(), attribute.isNull() ? linkAttribute(element) : attribute);
 }
 
 VisitedLinkState::VisitedLinkState(const Document& document)
     : m_document(document)
 {
 }
 
 void VisitedLinkState::invalidateStyleForAllLinks()
@@ skipping 37 matching lines @@
     if (LinkHash hash = linkHashForElement(element, attribute)) {
         m_linksCheckedForVisitedState.add(hash);
         if (blink::Platform::current()->isLinkVisited(hash))
             return InsideVisitedLink;
     }
 
     return InsideUnvisitedLink;
 }
 
 }