Add Traversal<*Element>::firstAncestor() API

Source/core/html/HTMLOptGroupElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * 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
@@ skipping 57 matching lines @@
 {
     HTMLElement::parseAttribute(name, value);
     recalcSelectOptions();
 
     if (name == disabledAttr)
         didAffectSelector(AffectedSelectorDisabled | AffectedSelectorEnabled);
 }
 
 void HTMLOptGroupElement::recalcSelectOptions()
 {
-    ContainerNode* select = parentNode();
-    while (select && !isHTMLSelectElement(*select))
-        select = select->parentNode();
-    if (select)
-        toHTMLSelectElement(select)->setRecalcListItems();
+    if (HTMLSelectElement* select = Traversal<HTMLSelectElement>::firstAncestor(*this))
+        select->setRecalcListItems();
 }
 
 void HTMLOptGroupElement::attach(const AttachContext& context)
 {
     if (context.resolvedStyle) {
         ASSERT(!m_style || m_style == context.resolvedStyle);
         m_style = context.resolvedStyle;
     }
     HTMLElement::attach(context);
 }
@@ skipping 27 matching lines @@
     // In WinIE, leading and trailing whitespace is ignored in options and optgroups. We match this behavior.
     itemText = itemText.stripWhiteSpace();
     // We want to collapse our whitespace too.  This will match other browsers.
     itemText = itemText.simplifyWhiteSpace();
 
     return itemText;
 }
 
 HTMLSelectElement* HTMLOptGroupElement::ownerSelectElement() const
 {
-    ContainerNode* select = parentNode();
-    while (select && !isHTMLSelectElement(*select))
-        select = select->parentNode();
-
-    if (!select)
-       return 0;
-
-    return toHTMLSelectElement(select);
+    return Traversal<HTMLSelectElement>::firstAncestor(*this);
 }
 
 void HTMLOptGroupElement::accessKeyAction(bool)
 {
     HTMLSelectElement* select = ownerSelectElement();
     // send to the parent to bring focus to the list box
     if (select && !select->focused())
         select->accessKeyAction(false);
 }
 
 } // namespace