Add support for entering/exiting HTML fullscreen from OOPIFs.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
@@ skipping 56 matching lines @@
         PrefixedRequest,
     };
 
     void requestFullscreen(Element&, RequestType);
     static void fullyExitFullscreen(Document&);
     void exitFullscreen();
 
     static bool fullscreenEnabled(Document&);
     Element* fullscreenElement() const { return !m_fullScreenElementStack.isEmpty() ? m_fullScreenElementStack.last().first.get() : 0; }
 
-    void didEnterFullScreenForElement(Element*);
-    void didExitFullScreenForElement(Element*);
+    // |isAncestorOfFullscreenElement| is used in OOPIF scenarios and is set to
+    // true when these functions are called to enter/exit fullscreen for an
+    // out-of-process descendant element.  In this case, we enter fullscreen
+    // for its (local) iframe container and make sure to also set the
+    // ContainsFullScreenElement flag on it (so that it gains the
+    // -webkit-full-screen-ancestor style).
+    void didEnterFullScreenForElement(Element*, bool isAncestorOfFullscreenElement);
+    void didExitFullScreenForElement(bool isAncestorOfFullscreenElement);
 
     void setFullScreenLayoutObject(LayoutFullScreen*);
     LayoutFullScreen* fullScreenLayoutObject() const { return m_fullScreenLayoutObject; }
     void fullScreenLayoutObjectDestroyed();
 
     void elementRemoved(Element&);
 
     // Mozilla API
     Element* webkitCurrentFullScreenElement() const { return m_fullScreenElement.get(); }
 
@@ skipping 37 matching lines @@
 inline Fullscreen* Fullscreen::fromIfExists(Document& document)
 {
     if (!document.hasFullscreenSupplement())
         return 0;
     return fromIfExistsSlow(document);
 }
 
 } // namespace blink
 
 #endif // Fullscreen_h