<label> should support form association by parser

Source/core/html/FormAssociatedElement.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 12 matching lines @@
  */
 
 #include "config.h"
 #include "core/html/FormAssociatedElement.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/IdTargetObserver.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/html/HTMLFormControlElement.h"
 #include "core/html/HTMLFormElement.h"
+#include "core/html/HTMLLabelElement.h"
 #include "core/html/HTMLObjectElement.h"
 #include "core/html/ValidityState.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 class FormAttributeTargetObserver : public IdTargetObserver {
     WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
@@ skipping 257 matching lines @@
 
 bool FormAssociatedElement::isFormControlElementWithState() const
 {
     return false;
 }
 
 const HTMLElement& toHTMLElement(const FormAssociatedElement& associatedElement)
 {
     if (associatedElement.isFormControlElement())
         return toHTMLFormControlElement(associatedElement);
-    // Assumes the element is an HTMLObjectElement
-    return toHTMLObjectElement(associatedElement);
+    else if (associatedElement.isLabelElement())
+        return toHTMLLabelElement(associatedElement);
+    else
+        return toHTMLObjectElement(associatedElement);
 }
 
 const HTMLElement* toHTMLElement(const FormAssociatedElement* associatedElement)
 {
     ASSERT(associatedElement);
     return &toHTMLElement(*associatedElement);
 }
 
 HTMLElement* toHTMLElement(FormAssociatedElement* associatedElement)
 {
@@ skipping 21 matching lines @@
     visitor->trace(m_element);
     IdTargetObserver::trace(visitor);
 }
 
 void FormAttributeTargetObserver::idTargetChanged()
 {
     m_element->formAttributeTargetChanged();
 }
 
 } // namespace Webcore