Add support for entering/exiting HTML fullscreen from OOPIFs.

third_party/WebKit/Source/web/FullscreenController.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 38 matching lines @@
     static FullscreenController* create(WebViewImpl*);
 
     void didEnterFullScreen();
     void didExitFullScreen();
 
     void enterFullScreenForElement(Element*);
     void exitFullScreenForElement(Element*);
 
     bool isFullscreen() { return m_fullScreenFrame; }
 
+    void setFullscreenIsForCrossProcessAncestor() { m_fullscreenIsForCrossProcessAncestor = true; }
+
     void updateSize();
 
     DECLARE_TRACE();
 
 protected:
     explicit FullscreenController(WebViewImpl*);
 
 private:
     void updatePageScaleConstraints(bool removeConstraints);
 
     WebViewImpl* m_webViewImpl;
 
     bool m_haveEnteredFullscreen;
     float m_exitFullscreenPageScaleFactor;
     IntSize m_exitFullscreenScrollOffset;
     FloatPoint m_exitFullscreenVisualViewportOffset;
 
     // If set, the WebView is transitioning to fullscreen for this element.
     Member<Element> m_provisionalFullScreenElement;
 
     // If set, the WebView is in fullscreen mode for an element in this frame.
     Member<LocalFrame> m_fullScreenFrame;
 
+    // If set, fullscreen is entered for an element that is a container for
+    // another fullscreen element in an out-of-process iframe.
+    bool m_fullscreenIsForCrossProcessAncestor;
+
     bool m_isCancelingFullScreen;
 };
 
 } // namespace blink
 
 #endif