Implement FullScreen using top layer.

third_party/WebKit/Source/core/dom/Fullscreen.h

Index: third_party/WebKit/Source/core/dom/Fullscreen.h
diff --git a/third_party/WebKit/Source/core/dom/Fullscreen.h b/third_party/WebKit/Source/core/dom/Fullscreen.h
index 8e8a8639599dcab5fb172f6a40c6c99a23332d2b..1f497748cd34e6c686b07245f8c8415060230ab6 100644
--- a/third_party/WebKit/Source/core/dom/Fullscreen.h
+++ b/third_party/WebKit/Source/core/dom/Fullscreen.h
@@ -41,7 +41,6 @@
 
 namespace blink {
 
-class LayoutFullScreen;
 class ComputedStyle;
 
 class CORE_EXPORT Fullscreen final
@@ -78,9 +77,7 @@ public:
     void didEnterFullScreenForElement(Element*);
     void didExitFullScreenForElement(Element*);
 
-    void setFullScreenLayoutObject(LayoutFullScreen*);
-    LayoutFullScreen* fullScreenLayoutObject() const { return m_fullScreenLayoutObject; }
-    void fullScreenLayoutObjectDestroyed();
+    void didUpdateSize(Element&);
 
     void elementRemoved(Element&);
 
@@ -94,6 +91,9 @@ public:
 
     DECLARE_VIRTUAL_TRACE();
 
+    using ElementStack = WillBeHeapVector<std::pair<RefPtrWillBeMember<Element>, RequestType>>;
+    const ElementStack& fullScreenElementStack() const { return m_fullScreenElementStack; }
+
 private:
     static Fullscreen* fromIfExistsSlow(Document&);
 
@@ -110,8 +110,7 @@ private:
     void eventQueueTimerFired(Timer<Fullscreen>*);
 
     RefPtrWillBeMember<Element> m_fullScreenElement;
-    WillBeHeapVector<std::pair<RefPtrWillBeMember<Element>, RequestType>> m_fullScreenElementStack;
-    LayoutFullScreen* m_fullScreenLayoutObject;
+    ElementStack m_fullScreenElementStack;
     Timer<Fullscreen> m_eventQueueTimer;
     WillBeHeapDeque<RefPtrWillBeMember<Event>> m_eventQueue;
     LayoutRect m_savedPlaceholderFrameRect;