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

Source/WebCore/page/FocusController.cpp

 /*
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nuanti Ltd.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 235 matching lines @@
     return node;
 }
 
 bool FocusController::setInitialFocus(FocusDirection direction, KeyboardEvent* event)
 {
     bool didAdvanceFocus = advanceFocus(direction, event, true);
     
     // If focus is being set initially, accessibility needs to be informed that system focus has moved 
     // into the web area again, even if focus did not change within WebCore. PostNotification is called instead
     // of handleFocusedUIElementChanged, because this will send the notification even if the element is the same.
-    if (AXObjectCache* cache = focusedOrMainFrame()->document()->existingAXObjectCache())
-        cache->postNotification(focusedOrMainFrame()->document(), AXObjectCache::AXFocusedUIElementChanged, true);
+    if (AXObjectCache::accessibilityEnabled())
+        focusedOrMainFrame()->document()->axObjectCache()->postNotification(focusedOrMainFrame()->document(), AXObjectCache::AXFocusedUIElementChanged, true);
 
     return didAdvanceFocus;
 }
 
 bool FocusController::advanceFocus(FocusDirection direction, KeyboardEvent* event, bool initialFocus)
 {
     switch (direction) {
     case FocusDirectionForward:
     case FocusDirectionBackward:
         return advanceFocusInDocumentOrder(direction, event, initialFocus);
@@ skipping 605 matching lines @@
         startingRect = nodeRectInAbsoluteCoordinates(container, true /* ignore border */);
         container = scrollableEnclosingBoxOrParentFrameForNodeInDirection(direction, container);
         if (container && container->isDocumentNode())
             toDocument(container)->updateLayoutIgnorePendingStylesheets();
     } while (!consumed && container);
 
     return consumed;
 }
 
 } // namespace WebCore