Move Document pointer from Frame to LocalFrame.

Source/core/frame/LocalFrame.cpp

Index: Source/core/frame/LocalFrame.cpp
diff --git a/Source/core/frame/LocalFrame.cpp b/Source/core/frame/LocalFrame.cpp
index d7bf03055669cd757e40c6c3a23d1d88d406bdf7..4a0216aba31452b0684abef9a19a9d235283d676 100644
--- a/Source/core/frame/LocalFrame.cpp
+++ b/Source/core/frame/LocalFrame.cpp
@@ -293,6 +293,16 @@ VisiblePosition LocalFrame::visiblePositionForPoint(const IntPoint& framePoint)
     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())
@@ -603,4 +613,13 @@ double LocalFrame::devicePixelRatio() const
     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