Sync "fully exit fullscreen" with the spec

Source/core/dom/Fullscreen.cpp

 /*
  * 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 269 matching lines @@
 
         // 7. Optionally, display a message indicating how the user can exit displaying the context object fullscreen.
         return;
     } while (0);
 
     enqueueErrorEvent(element, requestType);
 }
 
 void Fullscreen::fullyExitFullscreen()
 {
-    // "To fully exit fullscreen act as if the exitFullscreen() method was invoked on the top-level browsing
-    // context's document and subsequently empty that document's fullscreen element stack."
-    if (!fullscreenElementFrom(document()->topDocument()))
+    // To fully exit fullscreen, run these steps:
+
+    // 1. Let |doc| be the top-level browsing context's document.
+    Document& doc = document()->topDocument();
+
+    // 2. If |doc|'s fullscreen element stack is empty, terminate these steps.
+    if (!fullscreenElementFrom(doc))
         return;
 
-    // To achieve that aim, remove all the elements from the top document's stack except for the first before
-    // calling exitFullscreen():
-    WillBeHeapVector<std::pair<RefPtrWillBeMember<Element>, RequestType> > replacementFullscreenElementStack;
-    Fullscreen& topFullscreen = from(document()->topDocument());
-    replacementFullscreenElementStack.append(topFullscreen.m_fullScreenElementStack.last());
-    topFullscreen.m_fullScreenElementStack.swap(replacementFullscreenElementStack);
-    topFullscreen.exitFullscreen();
+    // 3. Remove elements from |doc|'s fullscreen element stack until only the top element is left.
+    size_t stackSize = from(doc).m_fullScreenElementStack.size();
+    from(doc).m_fullScreenElementStack.remove(0, stackSize - 1);
+    ASSERT(from(doc).m_fullScreenElementStack.size() == 1);
+
+    // 4. Act as if the exitFullscreen() method was invoked on |doc|.
+    from(doc).exitFullscreen();
 }
 
 void Fullscreen::exitFullscreen()
 {
     // The exitFullscreen() method must run these steps:
 
     // 1. Let doc be the context object. (i.e. "this")
     Document* currentDoc = document();
     if (!currentDoc->isActive())
         return;
@@ skipping 288 matching lines @@
 void Fullscreen::trace(Visitor* visitor)
 {
     visitor->trace(m_fullScreenElement);
     visitor->trace(m_fullScreenElementStack);
     visitor->trace(m_fullScreenRenderer);
     visitor->trace(m_eventQueue);
     DocumentSupplement::trace(visitor);
 }
 
 } // namespace blink