Implement computedRole and computedName (behind a flag)

Source/core/dom/Document.h

 /*
  * 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, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 482 matching lines @@
     void prepareForDestruction();
 
     // If you have a Document, use renderView() instead which is faster.
     void renderer() const = delete;
 
     RenderView* renderView() const { return m_renderView; }
 
     Document& axObjectCacheOwner() const;
     AXObjectCache* existingAXObjectCache() const;
     AXObjectCache* axObjectCache() const;
+    AXObjectCache* alwaysCreateAxObjectCache() const;
     void clearAXObjectCache();
 
     // to get visually ordered hebrew and arabic pages right
     bool visuallyOrdered() const { return m_visuallyOrdered; }
 
     DocumentLoader* loader() const;
 
     void open(Document* ownerDocument = nullptr, ExceptionState& = ASSERT_NO_EXCEPTION);
     PassRefPtrWillBeRawPtr<DocumentParser> implicitOpen();
 
@@ skipping 908 matching lines @@
 DEFINE_TYPE_CASTS(TreeScope, Document, document, true, true);
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLiveDocumentInstances();
 #endif
 
 #endif // Document_h