Add isHTMLPlugInElement() helpers for consistency with other HTML elements

Source/core/rendering/RenderEmbeddedObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006, 2008, 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.
@@ skipping 10 matching lines @@
  *
  */
 
 #include "config.h"
 #include "core/rendering/RenderEmbeddedObject.h"
 
 #include "CSSValueKeywords.h"
 #include "HTMLNames.h"
 #include "core/frame/LocalFrame.h"
 #include "core/html/HTMLIFrameElement.h"
+#include "core/html/HTMLPlugInElement.h"
 #include "core/page/Page.h"
 #include "core/frame/Settings.h"
 #include "core/plugins/PluginView.h"
 #include "core/rendering/LayoutRectRecorder.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderTheme.h"
 #include "core/rendering/RenderView.h"
 #include "platform/fonts/Font.h"
 #include "platform/fonts/FontSelector.h"
 #include "platform/graphics/GraphicsContextStateSaver.h"
@@ skipping 61 matching lines @@
 }
 
 bool RenderEmbeddedObject::showsUnavailablePluginIndicator() const
 {
     return m_showsUnavailablePluginIndicator;
 }
 
 void RenderEmbeddedObject::paintContents(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     Element* element = toElement(node());
-    if (!element || !element->isPluginElement())
+    if (!isHTMLPlugInElement(element))
         return;
 
     RenderPart::paintContents(paintInfo, paintOffset);
 }
 
 void RenderEmbeddedObject::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     if (showsUnavailablePluginIndicator()) {
         RenderReplaced::paint(paintInfo, paintOffset);
         return;
@@ skipping 123 matching lines @@
 {
     return false;
 }
 
 bool RenderEmbeddedObject::canHaveChildren() const
 {
     return false;
 }
 
 }