Add Blink APIs for frame tree mirroring.

Source/core/html/HTMLFrameOwnerElement.h

Index: Source/core/html/HTMLFrameOwnerElement.h
diff --git a/Source/core/html/HTMLFrameOwnerElement.h b/Source/core/html/HTMLFrameOwnerElement.h
index a8bbe75f0965eeeae6bf8301273f91145de9c8e0..94c2b30ae6964e14a50560159db375ab47ca4037 100644
--- a/Source/core/html/HTMLFrameOwnerElement.h
+++ b/Source/core/html/HTMLFrameOwnerElement.h
@@ -37,11 +37,6 @@ class HTMLFrameOwnerElement : public HTMLElement, public FrameOwner {
 public:
     virtual ~HTMLFrameOwnerElement();
 
-    // FrameOwner overrides:
-    virtual bool isLocal() const { return true; }
-    virtual SandboxFlags sandboxFlags() const OVERRIDE { return m_sandboxFlags; }
-    virtual void dispatchLoad() OVERRIDE;
-
     Frame* contentFrame() const { return m_contentFrame; }
     DOMWindow* contentWindow() const;
     Document* contentDocument() const;
@@ -88,6 +83,11 @@ private:
     virtual bool isKeyboardFocusable() const OVERRIDE;
     virtual bool isFrameOwnerElement() const OVERRIDE FINAL { return true; }
 
+    // FrameOwner overrides:
+    virtual bool isLocal() const { return true; }
+    virtual SandboxFlags sandboxFlags() const OVERRIDE { return m_sandboxFlags; }
+    virtual void dispatchLoad() OVERRIDE;
+
     Frame* m_contentFrame;
     RefPtr<Widget> m_widget;
     SandboxFlags m_sandboxFlags;