Implement computedRole and computedName (behind a flag)

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 2243 matching lines @@
         return 0;
 
     return axObjectCacheOwner().m_axObjectCache.get();
 }
 
 AXObjectCache* Document::axObjectCache() const
 {
     Settings* settings = this->settings();
     if (!settings || !settings->accessibilityEnabled())
         return 0;
+    return alwaysCreateAxObjectCache();
+}
 
+AXObjectCache* Document::alwaysCreateAxObjectCache() const
+{
     // 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& cacheOwner = this->axObjectCacheOwner();
 
     // If the document has already been detached, do not make a new axObjectCache.
     if (!cacheOwner.renderView())
         return 0;
 
@@ skipping 3542 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