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

Source/core/html/HTMLFormControlElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * 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 86 matching lines @@
 bool HTMLFormControlElement::formNoValidate() const
 {
     return fastHasAttribute(formnovalidateAttr);
 }
 
 void HTMLFormControlElement::updateAncestorDisabledState() const
 {
     HTMLFieldSetElement* fieldSetAncestor = 0;
     ContainerNode* legendAncestor = 0;
     for (ContainerNode* ancestor = parentNode(); ancestor; ancestor = ancestor->parentNode()) {
-        if (!legendAncestor && ancestor->hasTagName(legendTag))
+        if (!legendAncestor && isHTMLLegendElement(*ancestor))
             legendAncestor = ancestor;
-        if (ancestor->hasTagName(fieldsetTag)) {
+        if (isHTMLFieldSetElement(*ancestor)) {
             fieldSetAncestor = toHTMLFieldSetElement(ancestor);
             break;
         }
     }
     m_ancestorDisabledState = (fieldSetAncestor && fieldSetAncestor->isDisabledFormControl() && !(legendAncestor && legendAncestor == fieldSetAncestor->legend())) ? AncestorDisabledStateDisabled : AncestorDisabledStateEnabled;
 }
 
 void HTMLFormControlElement::ancestorDisabledStateWasChanged()
 {
     m_ancestorDisabledState = AncestorDisabledStateUnknown;
@@ skipping 231 matching lines @@
 short HTMLFormControlElement::tabIndex() const
 {
     // Skip the supportsFocus check in HTMLElement.
     return Element::tabIndex();
 }
 
 bool HTMLFormControlElement::recalcWillValidate() const
 {
     if (m_dataListAncestorState == Unknown) {
         for (ContainerNode* ancestor = parentNode(); ancestor; ancestor = ancestor->parentNode()) {
-            if (ancestor->hasTagName(datalistTag)) {
+            if (isHTMLDataListElement(*ancestor)) {
                 m_dataListAncestorState = InsideDataList;
                 break;
             }
         }
         if (m_dataListAncestorState == Unknown)
             m_dataListAncestorState = NotInsideDataList;
     }
     return m_dataListAncestorState == NotInsideDataList && !isDisabledOrReadOnly();
 }
 
@@ skipping 132 matching lines @@
 
 void HTMLFormControlElement::setFocus(bool flag)
 {
     LabelableElement::setFocus(flag);
 
     if (!flag && wasChangedSinceLastFormControlChangeEvent())
         dispatchFormControlChangeEvent();
 }
 
 } // namespace Webcore