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

Source/core/accessibility/AXListBoxOption.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 42 matching lines @@
 PassRefPtr<AXListBoxOption> AXListBoxOption::create()
 {
     return adoptRef(new AXListBoxOption());
 }
 
 bool AXListBoxOption::isEnabled() const
 {
     if (!m_optionElement)
         return false;
 
-    if (m_optionElement->hasTagName(optgroupTag))
+    if (isHTMLOptGroupElement(*m_optionElement))
         return false;
 
     if (equalIgnoringCase(getAttribute(aria_disabledAttr), "true"))
         return false;
 
     if (m_optionElement->hasAttribute(disabledAttr))
         return false;
 
     return true;
 }
@@ skipping 43 matching lines @@
         return true;
 
     if (accessibilityIsIgnoredByDefault())
         return true;
 
     return parentObject()->accessibilityIsIgnored();
 }
 
 bool AXListBoxOption::canSetSelectedAttribute() const
 {
-    if (!m_optionElement)
-        return false;
-
-    if (!m_optionElement->hasTagName(optionTag))
+    if (!isHTMLOptionElement(m_optionElement))
         return false;
 
     if (m_optionElement->isDisabledFormControl())
         return false;
 
     HTMLSelectElement* selectElement = listBoxOptionParentNode();
     if (selectElement && selectElement->isDisabledFormControl())
         return false;
 
     return true;
@@ skipping 76 matching lines @@
     unsigned length = listItems.size();
     for (unsigned i = 0; i < length; i++) {
         if (listItems[i] == m_optionElement)
             return i;
     }
 
     return -1;
 }
 
 } // namespace WebCore