Implement :valid and :invalid pseudoclass for <form>

Source/core/css/resolver/SharedStyleFinder.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 66 matching lines @@
 
     if (candidate.isDefaultButtonForForm() != element().isDefaultButtonForForm())
         return false;
 
     if (document().containsValidityStyleRules()) {
         bool willValidate = candidate.willValidate();
 
         if (willValidate != element().willValidate())
             return false;
 
-        if (willValidate && (candidate.isValidFormControlElement() != element().isValidFormControlElement()))
+        if (willValidate && (candidate.isValidElement() != element().isValidElement()))
             return false;
 
         if (candidate.isInRange() != element().isInRange())
             return false;
 
         if (candidate.isOutOfRange() != element().isOutOfRange())
             return false;
     }
 
     return true;
@@ skipping 238 matching lines @@
     // Tracking child index requires unique style for each node. This may get set by the sibling rule match above.
     if (!element().parentElementOrShadowRoot()->childrenSupportStyleSharing()) {
         INCREMENT_STYLE_STATS_COUNTER(m_styleResolver, sharedStyleRejectedByParent);
         return 0;
     }
 
     return shareElement->renderStyle();
 }
 
 }