Split the frame tree logic out of HistoryItem

Source/core/frame/History.cpp

 /*
  * Copyright (C) 2007 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 52 matching lines @@
 {
     m_lastStateObjectRequested = stateInternal();
     return m_lastStateObjectRequested.get();
 }
 
 SerializedScriptValue* History::stateInternal() const
 {
     if (!m_frame)
         return 0;
 
-    if (HistoryItem* historyItem = m_frame->loader().history()->currentItem())
+    if (HistoryItem* historyItem = m_frame->page()->history()->currentItem(m_frame))
         return historyItem->stateObject();
 
     return 0;
 }
 
 bool History::stateChanged() const
 {
     return m_lastStateObjectRequested != stateInternal();
 }
 
@@ skipping 66 matching lines @@
     KURL fullURL = urlForState(urlString);
     if (!fullURL.isValid() || !m_frame->document()->securityOrigin()->canRequest(fullURL)) {
         // We can safely expose the URL to JavaScript, as a) no redirection takes place: JavaScript already had this URL, b) JavaScript can only access a same-origin History object.
         es.throwSecurityError("A history state object with URL '" + fullURL.elidedString() + "' cannot be created in a document with origin '" + m_frame->document()->securityOrigin()->toString() + "'.");
         return;
     }
     m_frame->loader().updateForSameDocumentNavigation(fullURL, sameDocumentNavigationSource, data, FrameLoader::DoNotUpdateBackForwardList);
 }
 
 } // namespace WebCore