Introduce isHTMLVideoElement and toHTMLVideoElement

Source/core/html/HTMLImageLoader.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "config.h"
 #include "core/html/HTMLImageLoader.h"
 
 #include "HTMLNames.h"
 #include "core/dom/Element.h"
 #include "core/dom/Event.h"
 #include "core/dom/EventNames.h"
 #include "core/html/HTMLObjectElement.h"
+#include "core/html/HTMLVideoElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/loader/cache/CachedImage.h"
 
 namespace WebCore {
 
 HTMLImageLoader::HTMLImageLoader(Element* node)
     : ImageLoader(node)
 {
 }
 
 HTMLImageLoader::~HTMLImageLoader()
 {
 }
 
 void HTMLImageLoader::dispatchLoadEvent()
 {
     // HTMLVideoElement uses this class to load the poster image, but it should not fire events for loading or failure.
-    if (element()->hasTagName(HTMLNames::videoTag))
+    if (isHTMLVideoElement(element()))
         return;
 
     bool errorOccurred = image()->errorOccurred();
     if (!errorOccurred && image()->response().httpStatusCode() >= 400)
         errorOccurred = element()->hasTagName(HTMLNames::objectTag); // An <object> considers a 404 to be an error and should fire onerror.
     element()->dispatchEvent(Event::create(errorOccurred ? eventNames().errorEvent : eventNames().loadEvent, false, false));
 }
 
 String HTMLImageLoader::sourceURI(const AtomicString& attr) const
 {
     return stripLeadingAndTrailingHTMLSpaces(attr);
 }
 
 void HTMLImageLoader::notifyFinished(CachedResource*)
 {
     CachedImage* cachedImage = image();
 
     RefPtr<Element> element = this->element();
     ImageLoader::notifyFinished(cachedImage);
 
     bool loadError = cachedImage->errorOccurred() || cachedImage->response().httpStatusCode() >= 400;
 
     if (loadError && element->hasTagName(HTMLNames::objectTag))
         static_cast<HTMLObjectElement*>(element.get())->renderFallbackContent();
 }
 
 }