Use new is*Element() helper functions in DOM code

Source/core/dom/Text.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 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
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 18 matching lines @@
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/NodeRenderStyle.h"
 #include "core/dom/NodeRenderingTraversal.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/RenderTreeBuilder.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/events/ScopedEventQueue.h"
 #include "core/rendering/RenderCombineText.h"
 #include "core/rendering/RenderText.h"
 #include "core/rendering/svg/RenderSVGInlineText.h"
+#include "core/svg/SVGForeignObjectElement.h"
 #include "wtf/text/CString.h"
 #include "wtf/text/StringBuilder.h"
 
 using namespace std;
 
 namespace WebCore {
 
 PassRefPtr<Text> Text::create(Document& document, const String& data)
 {
     return adoptRef(new Text(document, data, CreateText));
@@ skipping 234 matching lines @@
             // Whitespace at the start of a block just goes away.  Don't even
             // make a render object for this text.
             return false;
     }
     return true;
 }
 
 static bool isSVGText(Text* text)
 {
     Node* parentOrShadowHostNode = text->parentOrShadowHostNode();
-    return parentOrShadowHostNode->isSVGElement() && !parentOrShadowHostNode->hasTagName(SVGNames::foreignObjectTag);
+    ASSERT(parentOrShadowHostNode);
+    return parentOrShadowHostNode->isSVGElement() && !isSVGForeignObjectElement(*parentOrShadowHostNode);
 }
 
 RenderText* Text::createTextRenderer(RenderStyle* style)
 {
     if (isSVGText(this))
         return new RenderSVGInlineText(this, dataImpl());
 
     if (style->hasTextCombine())
         return new RenderCombineText(this, dataImpl());
 
@@ skipping 64 matching lines @@
             result.appendLiteral("; ");
         result.appendLiteral("value=");
         result.append(s);
     }
 
     strncpy(buffer, result.toString().utf8().data(), length - 1);
 }
 #endif
 
 } // namespace WebCore