[WIP] Migrate Fullscreen to use top layer instead of RenderFullScreen

Source/core/html/HTMLDialogElement.h

Index: Source/core/html/HTMLDialogElement.h
diff --git a/Source/core/html/HTMLDialogElement.h b/Source/core/html/HTMLDialogElement.h
index 385b96ef01270f5d17052dd3801aceaefec576fc..9df9851e6ab90e6956bda775bc8ec1b7331be7fc 100644
--- a/Source/core/html/HTMLDialogElement.h
+++ b/Source/core/html/HTMLDialogElement.h
@@ -43,6 +43,8 @@ public:
     void closeDialog(const String& returnValue = String());
     void show();
     void showModal(ExceptionState&);
+    bool isModal() { return m_modal; }
+    void setModal(bool modal) { m_modal = modal; }
 
     enum CenteringMode { Uninitialized, Centered, NotCentered };
     CenteringMode centeringMode() const { return m_centeringMode; }
@@ -62,12 +64,14 @@ private:
 
     virtual bool isPresentationAttribute(const QualifiedName&) const OVERRIDE;
     virtual void defaultEventHandler(Event*) OVERRIDE;
+    virtual void removedFrom(ContainerNode*) OVERRIDE;
 
     void forceLayoutForCentering();
 
     CenteringMode m_centeringMode;
     LayoutUnit m_centeredPosition;
     String m_returnValue;
+    bool m_modal;
 };
 
 inline bool isHTMLDialogElement(const Node& node)