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

Source/core/html/HTMLEmbedElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006, 2008, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * 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 36 matching lines @@
 
 PassRefPtr<HTMLEmbedElement> HTMLEmbedElement::create(Document& document, bool createdByParser)
 {
     RefPtr<HTMLEmbedElement> element = adoptRef(new HTMLEmbedElement(document, createdByParser));
     element->ensureUserAgentShadowRoot();
     return element.release();
 }
 
 static inline RenderWidget* findWidgetRenderer(const Node* n)
 {
-    if (!n->renderer()) {
-        do {
-            n = n->parentNode();
-        } while (n && !isHTMLObjectElement(*n));
-    }
+    if (!n->renderer())
+        n = Traversal<HTMLObjectElement>::firstAncestor(*n);
 
     if (n && n->renderer() && n->renderer()->isWidget())
         return toRenderWidget(n->renderer());
 
     return 0;
 }
 
 RenderWidget* HTMLEmbedElement::existingRenderWidget() const
 {
     return findWidgetRenderer(this);
@@ skipping 124 matching lines @@
 }
 
 bool HTMLEmbedElement::isInteractiveContent() const
 {
     return true;
 }
 
 bool HTMLEmbedElement::isExposed() const
 {
     // http://www.whatwg.org/specs/web-apps/current-work/#exposed
-    for (Node* ancestor = parentNode(); ancestor; ancestor = ancestor->parentNode()) {
-        if (isHTMLObjectElement(*ancestor) && toHTMLObjectElement(*ancestor).isExposed())
+    for (HTMLObjectElement* object = Traversal<HTMLObjectElement>::firstAncestor(*this); object; object = Traversal<HTMLObjectElement>::firstAncestor(*object)) {
+        if (object->isExposed())
             return false;
     }
     return true;
 }
 
 }