Use new is*Element() helper functions even more in HTML code

Source/core/html/HTMLFrameElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann (hausmann@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2006, 2009 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
@@ skipping 41 matching lines @@
 }
 
 RenderObject* HTMLFrameElement::createRenderer(RenderStyle*)
 {
     return new RenderFrame(this);
 }
 
 static inline HTMLFrameSetElement* containingFrameSetElement(Node* node)
 {
     while ((node = node->parentNode())) {
-        if (node->hasTagName(framesetTag))
+        if (isHTMLFrameSetElement(*node))
             return toHTMLFrameSetElement(node);
     }
     return 0;
 }
 
 bool HTMLFrameElement::noResize() const
 {
     return hasAttribute(noresizeAttr);
 }
 
@@ skipping 14 matching lines @@
         m_frameBorderSet = !value.isNull();
         // FIXME: If we are already attached, this has no effect.
     } else if (name == noresizeAttr) {
         if (renderer())
             renderer()->updateFromElement();
     } else
         HTMLFrameElementBase::parseAttribute(name, value);
 }
 
 } // namespace WebCore