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

Source/core/accessibility/AXMenuListOption.cpp

 /*
  * Copyright (C) 2010 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 20 matching lines @@
 namespace WebCore {
 
 using namespace HTMLNames;
 
 AXMenuListOption::AXMenuListOption()
 {
 }
 
 void AXMenuListOption::setElement(HTMLElement* element)
 {
-    ASSERT_ARG(element, element->hasTagName(optionTag));
+    ASSERT_ARG(element, isHTMLOptionElement(element));
     m_element = element;
 }
 
 Element* AXMenuListOption::actionElement() const
 {
     return m_element.get();
 }
 
 bool AXMenuListOption::isEnabled() const
 {
@@ skipping 51 matching lines @@
 
     return grandparent->elementRect();
 }
 
 String AXMenuListOption::stringValue() const
 {
     return toHTMLOptionElement(m_element)->text();
 }
 
 } // namespace WebCore