Replace elementHasLegalLinkAttribute() helper with virtual function

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 59 matching lines @@
 
     HTMLPlugInElement::parseAttribute(name, value);
 }
 
 bool HTMLAppletElement::isURLAttribute(const Attribute& attribute) const
 {
     return attribute.name() == codebaseAttr || attribute.name() == objectAttr
         || HTMLPlugInElement::isURLAttribute(attribute);
 }
 
+bool HTMLAppletElement::hasLegalLinkAttribute(const QualifiedName& name) const
+{
+    return name == codebaseAttr || HTMLPlugInElement::hasLegalLinkAttribute(name);
+}
+
 bool HTMLAppletElement::rendererIsNeeded(const RenderStyle& style)
 {
     if (!fastHasAttribute(codeAttr) && !hasAuthorShadowRoot())
         return false;
     return HTMLPlugInElement::rendererIsNeeded(style);
 }
 
 RenderObject* HTMLAppletElement::createRenderer(RenderStyle* style)
 {
     if (!canEmbedJava() || hasAuthorShadowRoot())
@@ skipping 124 matching lines @@
 
     if (!document().contentSecurityPolicy()->allowObjectFromSource(url)
         || !document().contentSecurityPolicy()->allowPluginType(appletMimeType, appletMimeType, url)) {
         renderEmbeddedObject()->setPluginUnavailabilityReason(RenderEmbeddedObject::PluginBlockedByContentSecurityPolicy);
         return false;
     }
     return true;
 }
 
 }