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

Source/WebCore/html/HTMLSelectElement.cpp

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * 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, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
@@ skipping 362 matching lines @@
     setNeedsValidityCheck();
 
     HTMLFormControlElementWithState::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
 }
 
 void HTMLSelectElement::optionElementChildrenChanged()
 {
     setRecalcListItems();
     setNeedsValidityCheck();
 
-    if (renderer()) {
-        if (AXObjectCache* cache = renderer()->document()->existingAXObjectCache())
-            cache->childrenChanged(this);
-    }
+    if (AXObjectCache::accessibilityEnabled() && renderer())
+        renderer()->document()->axObjectCache()->childrenChanged(this);
 }
 
 void HTMLSelectElement::accessKeyAction(bool sendMouseEvents)
 {
     focus();
     dispatchSimulatedClick(0, sendMouseEvents ? SendMouseUpDownEvents : SendNoEvents);
 }
 
 void HTMLSelectElement::setMultiple(bool multiple)
 {
@@ skipping 320 matching lines @@
     m_activeSelectionAnchorIndex = -1;
     setOptionsChangedOnRenderer();
     setNeedsStyleRecalc();
     if (!inDocument()) {
         if (HTMLCollection* collection = cachedHTMLCollection(SelectOptions))
             collection->invalidateCache();
     }
     if (!inDocument())
         invalidateSelectedItems();
     
-    if (renderer()) {
-        if (AXObjectCache* cache = renderer()->document()->existingAXObjectCache())
-            cache->childrenChanged(this);
-    }
+    if (AXObjectCache::accessibilityEnabled() && renderer())
+        renderer()->document()->axObjectCache()->childrenChanged(this);
 }
 
 void HTMLSelectElement::recalcListItems(bool updateSelectedStates) const
 {
     m_listItems.clear();
 
     m_shouldRecalcListItems = false;
 
     HTMLOptionElement* foundSelected = 0;
     HTMLOptionElement* firstOption = 0;
@@ skipping 807 matching lines @@
     const Vector<HTMLElement*>& items = listItems();
     for (unsigned i = 0; i < items.size(); ++i) {
         if (items[i]->hasTagName(optionTag))
             ++options;
     }
 
     return options;
 }
 
 } // namespace