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

Source/core/html/HTMLNameCollection.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2011, 2012 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 45 matching lines @@
     if (!previous)
         current = ElementTraversal::firstWithin(ownerNode());
     else
         current = ElementTraversal::next(*previous, &ownerNode());
 
     for (; current; current = ElementTraversal::next(*current, &ownerNode())) {
         switch (type()) {
         case WindowNamedItems:
             // find only images, forms, applets, embeds and objects by name,
             // but anything by id
-            if (current->hasTagName(imgTag)
-                || current->hasTagName(formTag)
-                || current->hasTagName(appletTag)
-                || current->hasTagName(embedTag)
-                || current->hasTagName(objectTag)) {
+            if (isHTMLImageElement(*current)
+                || isHTMLFormElement(*current)
+                || isHTMLAppletElement(*current)
+                || isHTMLEmbedElement(*current)
+                || isHTMLObjectElement(*current)) {
                 if (current->getNameAttribute() == m_name)
                     return current;
             }
             if (current->getIdAttribute() == m_name)
                 return current;
             break;
         case DocumentNamedItems:
             // find images, forms, applets, embeds, objects and iframes by name,
             // applets and object by id, and images by id but only if they have
             // a name attribute (this very strange rule matches IE)
-            if (current->hasTagName(formTag)
-                || current->hasTagName(iframeTag)
-                || (current->hasTagName(embedTag) && toHTMLEmbedElement(current)->isExposed())) {
+            if (isHTMLFormElement(*current)
+                || isHTMLIFrameElement(*current)
+                || (isHTMLEmbedElement(*current) && toHTMLEmbedElement(*current).isExposed())) {
                 if (current->getNameAttribute() == m_name)
                     return current;
-            } else if (current->hasTagName(appletTag)
-                || (current->hasTagName(objectTag) && toHTMLObjectElement(current)->isExposed())) {
+            } else if (isHTMLAppletElement(*current)
+                || (isHTMLObjectElement(*current) && toHTMLObjectElement(*current).isExposed())) {
                 if (current->getNameAttribute() == m_name || current->getIdAttribute() == m_name)
                     return current;
-            } else if (current->hasTagName(imgTag)) {
+            } else if (isHTMLImageElement(*current)) {
                 if (current->getNameAttribute() == m_name || (current->getIdAttribute() == m_name && current->hasName()))
                     return current;
             }
             break;
         default:
             ASSERT_NOT_REACHED();
         }
     }
 
     return 0;
 }
 
 }