Move the frame tree into the embedder.

Source/web/WebFrameImpl.h

Index: Source/web/WebFrameImpl.h
diff --git a/Source/web/WebFrameImpl.h b/Source/web/WebFrameImpl.h
index dfecbc415c2917107e330475b8604a1d45015b7c..84a013253b0fdeabd09ccb5e45f9028d7a277c68 100644
--- a/Source/web/WebFrameImpl.h
+++ b/Source/web/WebFrameImpl.h
@@ -100,12 +100,12 @@ public:
     virtual void removeChild(WebFrame*) OVERRIDE;
     virtual WebFrame* parent() const OVERRIDE;
     virtual WebFrame* top() const OVERRIDE;
+    virtual WebFrame* previousSibling() const OVERRIDE;
+    virtual WebFrame* nextSibling() const OVERRIDE;
     virtual WebFrame* firstChild() const OVERRIDE;
     virtual WebFrame* lastChild() const OVERRIDE;
-    virtual WebFrame* nextSibling() const OVERRIDE;
-    virtual WebFrame* previousSibling() const OVERRIDE;
-    virtual WebFrame* traverseNext(bool wrap) const OVERRIDE;
     virtual WebFrame* traversePrevious(bool wrap) const OVERRIDE;
+    virtual WebFrame* traverseNext(bool wrap) const OVERRIDE;
     virtual WebFrame* findChildByName(const WebString&) const OVERRIDE;
     virtual WebFrame* findChildByExpression(const WebString&) const OVERRIDE;
     virtual WebDocument document() const OVERRIDE;
@@ -441,6 +441,11 @@ private:
     // The embedder retains a reference to the WebCore Frame while it is active in the DOM. This
     // reference is released when the frame is removed from the DOM or the entire page is closed.
     RefPtr<WebCore::Frame> m_frame;
+    WebFrameImpl* m_parent;
+    WebFrameImpl* m_previousSibling;
+    WebFrameImpl* m_nextSibling;
+    WebFrameImpl* m_firstChild;
+    WebFrameImpl* m_lastChild;
 
     WebFrameClient* m_client;
     WebPermissionClient* m_permissionClient;