Use new is*Element() helper functions more in core/ code

Source/core/loader/ImageLoader.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 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/loader/ImageLoader.h"
 
-#include "HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/events/Event.h"
 #include "core/events/EventSender.h"
 #include "core/fetch/CrossOriginAccessControl.h"
 #include "core/fetch/FetchRequest.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/html/HTMLObjectElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/rendering/RenderImage.h"
@@ skipping 337 matching lines @@
         return;
     }
     if (m_image) {
         m_image->removeClient(this);
         m_image = 0;
     }
 
     loadEventSender().cancelEvent(this);
     m_hasPendingLoadEvent = false;
 
-    if (m_element->hasTagName(HTMLNames::objectTag))
-        toHTMLObjectElement(m_element)->renderFallbackContent();
+    if (isHTMLObjectElement(*m_element))
+        toHTMLObjectElement(*m_element).renderFallbackContent();
 
     // Only consider updating the protection ref-count of the Element immediately before returning
     // from this function as doing so might result in the destruction of this ImageLoader.
     updatedHasPendingEvent();
 }
 
 void ImageLoader::dispatchPendingLoadEvent()
 {
     if (!m_hasPendingLoadEvent)
         return;
@@ skipping 69 matching lines @@
         handle->notifyImageSourceChanged();
     }
 }
 
 inline void ImageLoader::clearFailedLoadURL()
 {
     m_failedLoadURL = AtomicString();
 }
 
 }