Delay m_axObjectCache clearing during Document detach

Source/core/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 2103 matching lines @@
 
     m_lifecycle.advanceTo(DocumentLifecycle::Stopping);
 
     if (page())
         page()->documentDetached(this);
     InspectorInstrumentation::documentDetached(this);
 
     if (m_frame->loader().client()->sharedWorkerRepositoryClient())
         m_frame->loader().client()->sharedWorkerRepositoryClient()->documentDetached(this);
 
-    if (this == &axObjectCacheOwner())
-        clearAXObjectCache();
-
     stopActiveDOMObjects();
 
     // FIXME: consider using ActiveDOMObject.
     if (m_scriptedAnimationController)
         m_scriptedAnimationController->clearDocumentPointer();
     m_scriptedAnimationController.clear();
 
     if (svgExtensions())
         accessSVGExtensions().pauseAnimations();
 
     // FIXME: This shouldn't be needed once LocalDOMWindow becomes ExecutionContext.
     if (m_domWindow)
         m_domWindow->clearEventQueue();
 
     if (m_layoutView)
         m_layoutView->setIsInWindow(false);
 
     if (registrationContext())
         registrationContext()->documentWasDetached();
 
     m_hoverNode = nullptr;
     m_activeHoverElement = nullptr;
     m_autofocusElement = nullptr;
 
     if (m_focusedElement.get()) {
         RefPtrWillBeRawPtr<Element> oldFocusedElement = m_focusedElement;
         m_focusedElement = nullptr;
         if (frameHost())
             frameHost()->chrome().focusedNodeChanged(oldFocusedElement.get(), nullptr);
+    }
 
-    }
+    if (this == &axObjectCacheOwner())

[sof, 2015/04/27 06:27:07]

Does this mean that we no longer need to check & call clearAXObjectCache() in
~Document() ?

[je_julie(Not used), 2015/04/27 19:08:31]

You're right.
I can see that commitIfReady() calls detach(), commitData() calls ~Document()
and commitData() is always done after commitIfReady().
I updated patchset to remove it from ~Document().

+        clearAXObjectCache();
 
     m_layoutView = nullptr;
     ContainerNode::detach(context);
 
     styleEngine().didDetach();
 
     frameHost()->eventHandlerRegistry().documentDetached(*this);
 
     // This is required, as our LocalFrame might delete itself as soon as it detaches
     // us. However, this violates Node::detach() semantics, as it's never
@@ skipping 3592 matching lines @@
 #ifndef NDEBUG
 using namespace blink;
 void showLiveDocumentInstances()
 {
     WeakDocumentSet& set = liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (Document* document : set)
         fprintf(stderr, "- Document %p URL: %s\n", document, document->url().string().utf8().data());
 }
 #endif