Notify WebMediaPlayer when its ancestor enters/exists fullscreen.

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)
@@ skipping 23 matching lines @@
 #include "core/dom/ContextLifecycleObserver.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "platform/Supplementable.h"
 #include "platform/Timer.h"
 #include "platform/geometry/LayoutRect.h"
 #include "wtf/Deque.h"
 #include "wtf/RefPtr.h"
 #include "wtf/Vector.h"
 
+#include <set>
+
 namespace blink {
 
 class LayoutFullScreen;
 class ComputedStyle;
 
 class CORE_EXPORT Fullscreen final
     : public GarbageCollectedFinalized<Fullscreen>,
       public Supplement<Document>,
       public ContextLifecycleObserver {
   USING_GARBAGE_COLLECTED_MIXIN(Fullscreen);
 
  public:
   virtual ~Fullscreen();
   static const char* supplementName();
   static Fullscreen& from(Document&);
   static Fullscreen* fromIfExists(Document&);
   static Element* fullscreenElementFrom(Document&);
   static Element* currentFullScreenElementFrom(Document&);
   static bool isCurrentFullScreenElement(const Element&);
 
+  class FullscreenObserver {
+   public:
+    FullscreenObserver() {}
+    virtual ~FullscreenObserver() {}
+    virtual void onEnteredFullscreen() = 0;
+    virtual void onExitedFullscreen() = 0;
+  };
+
   enum RequestType {
     // Element.requestFullscreen()
     UnprefixedRequest,
     // Element.webkitRequestFullscreen()/webkitRequestFullScreen() and
     // HTMLVideoElement.webkitEnterFullscreen()/webkitEnterFullScreen()
     PrefixedRequest,
   };
 
   // |forCrossProcessDescendant| is used in OOPIF scenarios and is set to
   // true when fullscreen is requested for an out-of-process descendant
@@ skipping 37 matching lines @@
   // fullscreen element stack. It is still maintained separately from the
   // stack and is is what the :-webkit-full-screen pseudo-class depends on. It
   // should be removed, see https://crbug.com/402421.
   Element* currentFullScreenElement() const {
     return m_currentFullScreenElement.get();
   }
 
   // ContextLifecycleObserver:
   void contextDestroyed() override;
 
+  void registerObserver(FullscreenObserver*);
+  void removeObserver(FullscreenObserver*);
+
   DECLARE_VIRTUAL_TRACE();
 
  private:
   static Fullscreen* fromIfExistsSlow(Document&);
 
   explicit Fullscreen(Document&);
 
   Document* document();
 
   void clearFullscreenElementStack();
@@ skipping 15 matching lines @@
   // TODO(alexmos, dcheng): Currently, this assumes that if fullscreen was
   // entered for an element in an out-of-process iframe, then it's not
   // possible to re-enter fullscreen for a different element in this
   // document, since that requires a user gesture, which can't be obtained
   // since nothing in this document is visible, and since user gestures can't
   // be forwarded across processes. However, the latter assumption could
   // change if https://crbug.com/161068 is fixed so that cross-process
   // postMessage can carry user gestures.  If that happens, this should be
   // moved to be part of |m_fullscreenElementStack|.
   bool m_forCrossProcessDescendant;
+
+  std::set<FullscreenObserver*> m_observers;
 };
 
 inline Fullscreen* Fullscreen::fromIfExists(Document& document) {
   if (!document.hasFullscreenSupplement())
     return nullptr;
   return fromIfExistsSlow(document);
 }
 
 inline bool Fullscreen::isCurrentFullScreenElement(const Element& element) {
   if (Fullscreen* found = fromIfExists(element.document()))
     return found->currentFullScreenElement() == &element;
   return false;
 }
 
 }  // namespace blink
 
 #endif  // Fullscreen_h