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

Source/WebCore/editing/atk/FrameSelectionAtk.cpp

 /*
  * Copyright (C) 2009 Igalia S.L.
  *
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 71 matching lines @@
 
 void FrameSelection::notifyAccessibilityForSelectionChange()
 {
     if (!AXObjectCache::accessibilityEnabled())
         return;
 
     if (!m_selection.start().isNotNull() || !m_selection.end().isNotNull())
         return;
 
     RenderObject* focusedNode = m_selection.end().containerNode()->renderer();
-    AXObjectCache* cache = m_frame->document()->existingAXObjectCache();
-    if (!cache)
-        return;
-
-    AccessibilityObject* accessibilityObject = cache->getOrCreate(focusedNode);
+    AccessibilityObject* accessibilityObject = m_frame->document()->axObjectCache()->getOrCreate(focusedNode);
     if (!accessibilityObject)
         return;
 
     int offset;
     RefPtr<AccessibilityObject> object = objectFocusedAndCaretOffsetUnignored(accessibilityObject, offset);
     if (!object)
         return;
 
     emitTextSelectionChange(object.get(), m_selection, offset);
     maybeEmitTextFocusChange(object.release());
 }
 
 } // namespace WebCore