Implement :valid and :invalid pseudoclass for <form>

Source/core/html/HTMLFormElement.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, 2008, 2009 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 91 matching lines @@
 #if ENABLE(OILPAN)
     visitor->trace(m_pastNamesMap);
     visitor->trace(m_radioButtonGroupScope);
     visitor->trace(m_associatedElements);
     visitor->trace(m_imageElements);
     visitor->trace(m_pendingAutocompleteEventsQueue);
 #endif
     HTMLElement::trace(visitor);
 }
 
+bool HTMLFormElement::willValidate() const
+{
+    return true;
+}
+
+bool HTMLFormElement::isValidElement()
+{
+    return checkValidity();
+}
+
 bool HTMLFormElement::rendererIsNeeded(const RenderStyle& style)
 {
     if (!m_wasDemoted)
         return HTMLElement::rendererIsNeeded(style);
 
     ContainerNode* node = parentNode();
     if (!node || !node->renderer())
         return HTMLElement::rendererIsNeeded(style);
     RenderObject* parentRenderer = node->renderer();
     // FIXME: Shouldn't we also check for table caption (see |formIsTablePart| below).
@@ skipping 722 matching lines @@
 }
 
 void HTMLFormElement::setDemoted(bool demoted)
 {
     if (demoted)
         UseCounter::count(document(), UseCounter::DemotedFormElement);
     m_wasDemoted = demoted;
 }
 
 } // namespace