Sync requestFullscreen() and exitFullscreen() algorithms with the spec

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 a93806df06f2cf48317309277284fd6908d50385..7bc3a7f67c7c7f165f3aeaa01a7d681a0dfb99d1 100644
--- a/third_party/WebKit/Source/core/dom/Fullscreen.h
+++ b/third_party/WebKit/Source/core/dom/Fullscreen.h
@@ -35,7 +35,6 @@
 #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"
@@ -59,9 +58,8 @@ class CORE_EXPORT Fullscreen final
   static Fullscreen* fromIfExists(Document&);
   static Element* fullscreenElementFrom(Document&);
   static Element* fullscreenElementForBindingFrom(TreeScope&);
-  static Element* currentFullScreenElementFrom(Document&);
-  static Element* currentFullScreenElementForBindingFrom(Document&);
-  static bool isCurrentFullScreenElement(const Element&);
+  static size_t fullscreenElementStackSizeFrom(Document&);
+  static bool isFullscreenElement(const Element&);
 
   enum class RequestType {
     // Element.requestFullscreen()
@@ -69,25 +67,26 @@ class CORE_EXPORT Fullscreen final
     // Element.webkitRequestFullscreen()/webkitRequestFullScreen() and
     // HTMLVideoElement.webkitEnterFullscreen()/webkitEnterFullScreen()
     Prefixed,
+    // For WebRemoteFrameImpl to notify that a cross-process descendant frame
+    // has requested and is about to enter fullscreen.
+    PrefixedForCrossProcessDescendant,
   };
 
   static void requestFullscreen(Element&);
-
-  // |forCrossProcessDescendant| is used in OOPIF scenarios and is set to
-  // true when fullscreen is requested for an out-of-process descendant
-  // element.
-  static void requestFullscreen(Element&,
-                                RequestType,
-                                bool forCrossProcessDescendant = false);
+  static void requestFullscreen(Element&, RequestType);
 
   static void fullyExitFullscreen(Document&);
-  static void exitFullscreen(Document&);
+
+  enum class ExitType {
+    // Exits fullscreen for one element in the document.
+    Default,
+    // Fully exits fullscreen for the document.
+    Fully,
+  };
+
+  static void exitFullscreen(Document&, ExitType = ExitType::Default);
 
   static bool fullscreenEnabled(Document&);
-  // TODO(foolip): The fullscreen element stack is modified synchronously in
-  // requestFullscreen(), which is not per spec and means that
-  // |fullscreenElement()| is not always the same as
-  // |currentFullScreenElement()|, see https://crbug.com/402421.
   Element* fullscreenElement() const {
     return !m_fullscreenElementStack.isEmpty()
                ? m_fullscreenElementStack.back().first.get()
@@ -107,20 +106,6 @@ class CORE_EXPORT Fullscreen final
 
   void elementRemoved(Element&);
 
-  // Returns true if the current fullscreen element stack corresponds to a
-  // container for an actual fullscreen element in a descendant
-  // out-of-process iframe.
-  bool forCrossProcessDescendant() { return m_forCrossProcessDescendant; }
-
-  // Mozilla API
-  // TODO(foolip): |currentFullScreenElement()| is a remnant from before the
-  // 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;
 
@@ -133,33 +118,30 @@ class CORE_EXPORT Fullscreen final
 
   Document* document();
 
+  static void enqueueTaskForRequest(Document&,
+                                    Element&,
+                                    RequestType,
+                                    bool error);
+  static void runTaskForRequest(Document*, Element*, RequestType, bool error);
+
+  static void enqueueTaskForExit(Document&, ExitType);
+  static void runTaskForExit(Document*, ExitType);
+
   void clearFullscreenElementStack();
   void popFullscreenElementStack();
   void pushFullscreenElementStack(Element&, RequestType);
+  void fullscreenElementChanged(Element* fromElement,
+                                Element* toElement,
+                                RequestType toRequestType);
 
-  void enqueueChangeEvent(Document&, RequestType);
-  void enqueueErrorEvent(Element&, RequestType);
-  void eventQueueTimerFired(TimerBase*);
+  using ElementStackEntry = std::pair<Member<Element>, RequestType>;
+  using ElementStack = HeapVector<ElementStackEntry>;
+  ElementStack m_pendingRequests;
+  ElementStack m_fullscreenElementStack;
 
-  Member<Element> m_pendingFullscreenElement;
-  HeapVector<std::pair<Member<Element>, RequestType>> m_fullscreenElementStack;
-  Member<Element> m_currentFullScreenElement;
   LayoutFullScreen* m_fullScreenLayoutObject;
-  Timer<Fullscreen> m_eventQueueTimer;
-  HeapDeque<Member<Event>> m_eventQueue;
   LayoutRect m_savedPlaceholderFrameRect;
   RefPtr<ComputedStyle> m_savedPlaceholderComputedStyle;
-
-  // 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;
 };
 
 inline Fullscreen* Fullscreen::fromIfExists(Document& document) {
@@ -168,9 +150,9 @@ inline Fullscreen* Fullscreen::fromIfExists(Document& document) {
   return fromIfExistsSlow(document);
 }
 
-inline bool Fullscreen::isCurrentFullScreenElement(const Element& element) {
+inline bool Fullscreen::isFullscreenElement(const Element& element) {
   if (Fullscreen* found = fromIfExists(element.document()))
-    return found->currentFullScreenElement() == &element;
+    return found->fullscreenElement() == &element;
   return false;
 }