Refactor ScopedAXObjectCache to remove ref count

Source/web/WebAXObject.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 58 matching lines @@
 {
     if (!document || !document->view())
         return false;
     return document->lifecycle().state() >= DocumentLifecycle::LayoutClean
         || ((document->lifecycle().state() == DocumentLifecycle::StyleClean || document->lifecycle().state() == DocumentLifecycle::LayoutSubtreeChangeClean)
             && !document->view()->needsLayout());
 }
 #endif
 
 WebScopedAXContext::WebScopedAXContext(WebDocument& rootDocument)
-    : m_private(adoptRef(new ScopedAXObjectCache(*rootDocument.unwrap<Document>())))
+    : m_private(ScopedAXObjectCache::create(*rootDocument.unwrap<Document>()))
 {
 }
 
-WebScopedAXContext::~WebScopedAXContext()
-{
-    m_private.reset();
-}
-
 WebAXObject WebScopedAXContext::root() const
 {
     return WebAXObject(static_cast<AXObjectCacheImpl*>(m_private->get())->root());
 }
 
 void WebAXObject::reset()
 {
     m_private.reset();
 }
 
@@ skipping 1493 matching lines @@
     m_private = object;
     return *this;
 }
 
 WebAXObject::operator WTF::PassRefPtr<AXObject>() const
 {
     return m_private.get();
 }
 
 } // namespace blink