Use new Traversal<HTML*Element> API in HTML code

Source/core/html/HTMLAppletElement.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, 2012 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 149 matching lines @@
     paramNames.append("baseURL");
     KURL baseURL = document().baseURL();
     paramValues.append(baseURL.string());
 
     const AtomicString& mayScript = getAttribute(mayscriptAttr);
     if (!mayScript.isNull()) {
         paramNames.append("mayScript");
         paramValues.append(mayScript.string());
     }
 
-    for (Element* child = ElementTraversal::firstWithin(*this); child; child = ElementTraversal::nextSibling(*child)) {
-        if (!child->hasTagName(paramTag))
-            continue;
-
-        HTMLParamElement* param = toHTMLParamElement(child);
+    for (HTMLParamElement* param = Traversal<HTMLParamElement>::firstChild(*this); param; param = Traversal<HTMLParamElement>::nextSibling(*param)) {
         if (param->name().isEmpty())
             continue;
 
         paramNames.append(param->name());
         paramValues.append(param->value());
     }
 
     RefPtr<Widget> widget;
     if (frame->loader().allowPlugins(AboutToInstantiatePlugin))
         widget = frame->loader().client()->createJavaAppletWidget(this, baseURL, paramNames, paramValues);
@@ skipping 33 matching lines @@
 
     if (!document().contentSecurityPolicy()->allowObjectFromSource(url)
         || !document().contentSecurityPolicy()->allowPluginType(appletMimeType, appletMimeType, url)) {
         renderEmbeddedObject()->setPluginUnavailabilityReason(RenderEmbeddedObject::PluginBlockedByContentSecurityPolicy);
         return false;
     }
     return true;
 }
 
 }