Move Document pointer from Frame to LocalFrame.

Source/core/frame/LocalFrame.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Simon Hausmann <hausmann@kde.org>
  *                     2000 Stefan Schimanski <1Stein@gmx.de>
  *                     2001 George Staikos <staikos@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov <ap@nypop.com>
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 275 matching lines @@
         return VisiblePosition();
     RenderObject* renderer = node->renderer();
     if (!renderer)
         return VisiblePosition();
     VisiblePosition visiblePos = VisiblePosition(renderer->positionForPoint(result.localPoint()));
     if (visiblePos.isNull())
         visiblePos = VisiblePosition(firstPositionInOrBeforeNode(node));
     return visiblePos;
 }
 
+RenderView* LocalFrame::contentRenderer() const
+{
+    return document() ? document()->renderView() : 0;
+}
+
+Document* LocalFrame::document() const
+{
+    return m_domWindow ? m_domWindow->document() : 0;
+}
+
 Document* LocalFrame::documentAtPoint(const IntPoint& point)
 {
     if (!view())
         return 0;
 
     IntPoint pt = view()->windowToContents(point);
     HitTestResult result = HitTestResult(pt);
 
     if (contentRenderer())
         result = eventHandler().hitTestResultAtPoint(pt, HitTestRequest::ReadOnly | HitTestRequest::Active | HitTestRequest::ConfusingAndOftenMisusedDisallowShadowContent);
@@ skipping 290 matching lines @@
 double LocalFrame::devicePixelRatio() const
 {
     if (!m_host)
         return 0;
 
     double ratio = m_host->deviceScaleFactor();
     ratio *= pageZoomFactor();
     return ratio;
 }
 
+void LocalFrame::disconnectOwnerElement()
+{
+    if (ownerElement()) {
+        if (Document* doc = document())
+            doc->topDocument().clearAXObjectCache();

[dcheng, 2014/04/14 19:25:57]

Do you know what accessibility is planning on doing here? Right now the AXObject
cache always lives on the document of the top-most frame, but some/all of that
state moves to the browser, we can devirtualize this again right?

[kenrb, 2014/04/14 20:09:52]

I don't know much about accessibility, so I have just been trying to preserve
existing behavior.

+    }
+    Frame::disconnectOwnerElement();
+}
+
 } // namespace WebCore