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

Source/WebCore/rendering/RenderObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1847 matching lines @@
         // If our z-index changes value or our visibility changes,
         // we need to dirty our stacking context's z-order list.
         if (newStyle) {
             bool visibilityChanged = m_style->visibility() != newStyle->visibility() 
                 || m_style->zIndex() != newStyle->zIndex() 
                 || m_style->hasAutoZIndex() != newStyle->hasAutoZIndex();
 #if ENABLE(DASHBOARD_SUPPORT) || ENABLE(DRAGGABLE_REGION)
             if (visibilityChanged)
                 document()->setAnnotatedRegionsDirty(true);
 #endif
-            if (visibilityChanged) {
-                if (AXObjectCache* cache = document()->existingAXObjectCache())
-                    cache->childrenChanged(parent());
-            }
+            if (visibilityChanged && AXObjectCache::accessibilityEnabled())
+                document()->axObjectCache()->childrenChanged(parent());
 
             // Keep layer hierarchy visibility bits up to date if visibility changes.
             if (m_style->visibility() != newStyle->visibility()) {
                 if (RenderLayer* l = enclosingLayer()) {
                     if (newStyle->visibility() == VISIBLE)
                         l->setHasVisibleContent();
                     else if (l->hasVisibleContent() && (this == l->renderer() || l->renderer()->style()->visibility() != VISIBLE)) {
                         l->dirtyVisibleContentStatus();
                         if (diff > StyleDifferenceRepaintLayer)
                             repaint();
@@ skipping 522 matching lines @@
     // has a null frame, so we assert this. However, we don't want release builds to crash which is why we
     // check that the frame is not null.
     ASSERT(frame());
     if (frame() && frame()->eventHandler()->autoscrollRenderer() == this)
         frame()->eventHandler()->stopAutoscrollTimer(true);
 
     animation()->cancelAnimations(this);
 
     // For accessibility management, notify the parent of the imminent change to its child set.
     // We do it now, before remove(), while the parent pointer is still available.
-    if (AXObjectCache* cache = document()->existingAXObjectCache())
-        cache->childrenChanged(this->parent());
+    if (AXObjectCache::accessibilityEnabled())
+        document()->axObjectCache()->childrenChanged(this->parent());
 
     remove();
 
     // The remove() call above may invoke axObjectCache()->childrenChanged() on the parent, which may require the AX render
     // object for this renderer. So we remove the AX render object now, after the renderer is removed.
-    if (AXObjectCache* cache = document()->existingAXObjectCache())
-        cache->remove(this);
+    if (AXObjectCache::accessibilityEnabled())
+        document()->axObjectCache()->remove(this);
 
 #ifndef NDEBUG
     if (!documentBeingDestroyed() && view() && view()->hasRenderNamedFlowThreads()) {
         // After remove, the object and the associated information should not be in any flow thread.
         const RenderNamedFlowThreadList* flowThreadList = view()->flowThreadController()->renderNamedFlowThreadList();
         for (RenderNamedFlowThreadList::const_iterator iter = flowThreadList->begin(); iter != flowThreadList->end(); ++iter) {
             const RenderNamedFlowThread* renderFlowThread = *iter;
             ASSERT(!renderFlowThread->hasChild(this));
             ASSERT(!renderFlowThread->hasChildInfo(this));
         }
@@ skipping 783 matching lines @@
 {
     if (object1) {
         const WebCore::RenderObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showRenderTreeAndMark(object1, "*", object2, "-", 0);
     }
 }
 
 #endif