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

Source/WebCore/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 611 matching lines @@
     // Although the Document may be replaced synchronously, DocumentParsers
     // generally keep at least one reference to an Element which would in turn
     // has a reference to the Document.  If you hit this ASSERT, then that
     // assumption is wrong.  DocumentParser::detach() should ensure that even
     // if the DocumentParser outlives the Document it won't cause badness.
     ASSERT(!m_parser || m_parser->refCount() == 1);
     detachParser();
 
     m_renderArena.clear();
 
-    if (this == topDocument())
-        clearAXObjectCache();
+    clearAXObjectCache();
 
     m_decoder = 0;
 
     if (m_styleSheetList)
         m_styleSheetList->detachFromDocument();
 
     m_styleSheetCollection.clear();
 
     if (m_elemSheet)
         m_elemSheet->clearOwnerNode();
@@ skipping 1561 matching lines @@
     ScriptExecutionContext::suspendActiveDOMObjects(why);
 }
 
 void Document::resumeActiveDOMObjects()
 {
     ScriptExecutionContext::resumeActiveDOMObjects();
 }
 
 void Document::clearAXObjectCache()
 {
-    ASSERT(topDocument() == this);
     // Clear the cache member variable before calling delete because attempts
     // are made to access it during destruction.
-    m_axObjectCache.clear();
+    topDocument()->m_axObjectCache.release();
 }
 
-AXObjectCache* Document::existingAXObjectCache() const
+bool Document::axObjectCacheExists() const
 {
-    if (!AXObjectCache::accessibilityEnabled())
-        return 0;
-
-    // If the renderer is gone then we are in the process of destruction.
-    // This method will be called before m_frame = 0.
-    if (!topDocument()->renderer())
-        return 0;
-
-    return topDocument()->m_axObjectCache.get();
+    return topDocument()->m_axObjectCache;
 }
 
 AXObjectCache* Document::axObjectCache() const
 {
-    if (!AXObjectCache::accessibilityEnabled())
-        return 0;
-    
     // The only document that actually has a AXObjectCache is the top-level
     // document.  This is because we need to be able to get from any WebCoreAXObject
     // to any other WebCoreAXObject on the same page.  Using a single cache allows
     // lookups across nested webareas (i.e. multiple documents).
     Document* topDocument = this->topDocument();
-
-    // If the document has already been detached, do not make a new axObjectCache.
-    if (!topDocument->renderer())
-        return 0;
-
     ASSERT(topDocument == this || !m_axObjectCache);
     if (!topDocument->m_axObjectCache)
         topDocument->m_axObjectCache = adoptPtr(new AXObjectCache(topDocument));
     return topDocument->m_axObjectCache.get();
 }
 
 void Document::setVisuallyOrdered()
 {
     m_visuallyOrdered = true;
     if (renderer())
@@ skipping 1228 matching lines @@
                 // Re-get the widget in case updating the layout changed things.
                 focusWidget = widgetForNode(m_focusedNode.get());
             }
             if (focusWidget)
                 focusWidget->setFocus(true);
             else
                 view()->setFocus(true);
         }
     }
 
-    if (!focusChangeBlocked && m_focusedNode) {
-        // Create the AXObject cache in a focus change because Chromium relies on it.
-        if (AXObjectCache* cache = axObjectCache())
-            cache->handleFocusedUIElementChanged(oldFocusedNode.get(), newFocusedNode.get());
-    }
-
+#if PLATFORM(MAC) || PLATFORM(WIN) || PLATFORM(GTK) || PLATFORM(CHROMIUM)
+    if (!focusChangeBlocked && m_focusedNode && AXObjectCache::accessibilityEnabled())
+        axObjectCache()->handleFocusedUIElementChanged(oldFocusedNode.get(), newFocusedNode.get());
+#endif
     if (!focusChangeBlocked)
         page()->chrome()->focusedNodeChanged(m_focusedNode.get());
 
 SetFocusedNodeDone:
     updateStyleIfNeeded();
     return !focusChangeBlocked;
 }
     
 void Document::getFocusableNodes(Vector<RefPtr<Node> >& nodes)
 {
@@ skipping 2683 matching lines @@
         return;
 
     Vector<Element*> associatedFormControls;
     copyToVector(m_associatedFormControls, associatedFormControls);
 
     frame()->page()->chrome()->client()->didAssociateFormControls(associatedFormControls);
     m_associatedFormControls.clear();
 }
 
 } // namespace WebCore