Convert FullscreenController to use WebCallbacks

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 379e1f3e25ed2914b9c5be0401ad7f7d3d89f411..cbe62abd5c7796dfdfaacbfc50e62c52377bac5b 100644
--- a/third_party/WebKit/Source/core/dom/Fullscreen.h
+++ b/third_party/WebKit/Source/core/dom/Fullscreen.h
@@ -92,7 +92,6 @@ class CORE_EXPORT Fullscreen final
                : nullptr;
   }
 
-  void didEnterFullscreenForElement(Element*);
   void didExitFullscreen();
 
   void setFullScreenLayoutObject(LayoutFullScreen*);
@@ -123,12 +122,16 @@ class CORE_EXPORT Fullscreen final
   DECLARE_VIRTUAL_TRACE();
 
  private:
+  friend class RequestFullscreenCallbacks;
+
   static Fullscreen* fromIfExistsSlow(Document&);
 
   explicit Fullscreen(Document&);
 
   Document* document();
 
+  void didEnterFullscreen(Element&);
+
   void clearFullscreenElementStack();
   void popFullscreenElementStack();
   void pushFullscreenElementStack(Element&, RequestType);