Revert 146726 "AXObjectCache gets recreated during document tear..."

Source/WebCore/html/HTMLInputElement.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, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Samsung Electronics. All rights reserved.
@@ skipping 879 matching lines @@
 
     if (CheckedRadioButtons* buttons = checkedRadioButtons())
             buttons->updateCheckedState(this);
     if (renderer() && renderer()->style()->hasAppearance())
         renderer()->theme()->stateChanged(renderer(), CheckedState);
     setNeedsValidityCheck();
 
     // Ideally we'd do this from the render tree (matching
     // RenderTextView), but it's not possible to do it at the moment
     // because of the way the code is structured.
-    if (renderer()) {
-        if (AXObjectCache* cache = renderer()->document()->existingAXObjectCache())
-            cache->checkedStateChanged(this);
-    }
+    if (renderer() && AXObjectCache::accessibilityEnabled())
+        renderer()->document()->axObjectCache()->checkedStateChanged(this);
 
     // Only send a change event for items in the document (avoid firing during
     // parsing) and don't send a change event for a radio button that's getting
     // unchecked to match other browsers. DOM is not a useful standard for this
     // because it says only to fire change events at "lose focus" time, which is
     // definitely wrong in practice for these types of elements.
     if (eventBehavior != DispatchNoEvent && inDocument() && m_inputType->shouldSendChangeEventAfterCheckedChanged()) {
         setTextAsOfLastFormControlChangeEvent(String());
         dispatchFormControlChangeEvent();
     }
@@ skipping 1066 matching lines @@
 }
 
 #if ENABLE(INPUT_MULTIPLE_FIELDS_UI)
 PassRefPtr<RenderStyle> HTMLInputElement::customStyleForRenderer()
 {
     return m_inputType->customStyleForRenderer(document()->styleResolver()->styleForElement(this));
 }
 #endif
 
 } // namespace