Use new is*Element() helper functions further more in HTML code

Source/core/html/HTMLLIElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2006, 2007, 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 74 matching lines @@
     if (renderer() && renderer()->isListItem()) {
         RenderListItem* listItemRenderer = toRenderListItem(renderer());
 
         // Find the enclosing list node.
         Element* listNode = 0;
         Element* current = this;
         while (!listNode) {
             current = current->parentElement();
             if (!current)
                 break;
-            if (current->hasTagName(ulTag) || current->hasTagName(olTag))
+            if (isHTMLUListElement(*current) || isHTMLOListElement(*current))
                 listNode = current;
         }
 
         // If we are not in a list, tell the renderer so it can position us inside.
         // We don't want to change our style to say "inside" since that would affect nested nodes.
         if (!listNode) {
             listItemRenderer->setNotInList(true);
             listItemRenderer->updateMarkerLocation();
         }
 
         parseValue(fastGetAttribute(valueAttr));
     }
 }
 
 inline void HTMLLIElement::parseValue(const AtomicString& value)
 {
     ASSERT(renderer() && renderer()->isListItem());
 
     bool valueOK;
     int requestedValue = value.toInt(&valueOK);
     if (valueOK)
         toRenderListItem(renderer())->setExplicitValue(requestedValue);
     else
         toRenderListItem(renderer())->clearExplicitValue();
 }
 
 }