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

Source/WebCore/dom/ContainerNode.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.
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
@@ skipping 120 matching lines @@
         // (if the document changed or oldParent was in a shadow tree, AND *this is in a shadow tree).
         // Can we do better?
         treeScope()->adoptIfNeeded(child.get());
         if (attached() && !child->attached())
             child->attach();
     }
 }
 
 ContainerNode::~ContainerNode()
 {
-    if (documentInternal()) {
-        if (AXObjectCache* cache = documentInternal()->existingAXObjectCache())
-            cache->remove(this);
-    }
+    if (AXObjectCache::accessibilityEnabled() && documentInternal() && documentInternal()->axObjectCacheExists())
+        documentInternal()->axObjectCache()->remove(this);
 
     removeDetachedChildren();
 }
 
 static inline bool isChildTypeAllowed(ContainerNode* newParent, Node* child)
 {
     if (!child->isDocumentFragment())
         return newParent->childTypeAllowed(child->nodeType());
 
     for (Node* node = child->firstChild(); node; node = node->nextSibling()) {
@@ skipping 1024 matching lines @@
         return true;
 
     if (node->isElementNode() && toElement(node)->shadow())
         return true;
 
     return false;
 }
 #endif
 
 } // namespace WebCore