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

third_party/WebKit/Source/web/FullscreenController.cpp

 /*
  * 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 70 matching lines @@
   // Notify all local frames that we have entered fullscreen.
   for (Frame* frame = m_webViewImpl->page()->mainFrame(); frame;
        frame = frame->tree().traverseNext()) {
     if (!frame->isLocalFrame())
       continue;
     if (Document* document = toLocalFrame(frame)->document()) {
       if (Fullscreen* fullscreen = Fullscreen::fromIfExists(*document))
         fullscreen->didEnterFullscreen();
     }
   }
+
+  // TODO(foolip): If the top level browsing context (main frame) ends up with
+  // no fullscreen element, exit fullscreen again to recover.
 }
 
 void FullscreenController::didExitFullscreen() {
   // The browser process can exit fullscreen at any time, e.g. if the user
   // presses Esc. After |Browser::EnterFullscreenModeForTab()|,
   // |Browser::ExitFullscreenModeForTab()| will make it seem like we exit when
   // not even in fullscreen. Do nothing.
   if (m_state == State::Initial)
     return;
 
   updatePageScaleConstraints(true);
 
-  // Set |m_state| so that any |exitFullscreen()| calls from within
-  // |Fullscreen::didExitFullscreen()| do not call
-  // |WebFrameClient::exitFullscreen()| again.
-  // TODO(foolip): Remove this when state changes and events are synchronized
-  // with animation frames. https://crbug.com/402376
-  m_state = State::ExitingFullscreen;
-
-  // Notify all local frames that we have exited fullscreen.
-  // TODO(foolip): This should only need to notify the topmost local roots. That
-  // doesn't currently work because |Fullscreen::m_currentFullScreenElement|
-  // isn't set for the topmost document when an iframe goes fullscreen, but can
-  // be done once |m_currentFullScreenElement| is gone and all state is in the
-  // fullscreen element stack. https://crbug.com/402421
-  for (Frame* frame = m_webViewImpl->page()->mainFrame(); frame;
-       frame = frame->tree().traverseNext()) {
-    if (!frame->isLocalFrame())
-      continue;
-    if (Document* document = toLocalFrame(frame)->document()) {
-      if (Fullscreen* fullscreen = Fullscreen::fromIfExists(*document))
-        fullscreen->didExitFullscreen();
-    }
-  }
-
   // We need to wait until style and layout are updated in order to properly
   // restore scroll offsets since content may not be overflowing in the same way
   // until they are.
   m_state = State::NeedsScrollAndScaleRestore;
+
+  // Notify the topmost local frames that we have exited fullscreen.
+  // |Fullscreen::didExitFullscreen()| will take care of descendant frames.
+  for (Frame* frame = m_webViewImpl->page()->mainFrame(); frame;) {
+    Frame* nextFrame = frame->tree().traverseNext();
+
+    if (frame->isRemoteFrame()) {
+      frame = nextFrame;
+      continue;
+    }
+
+    DCHECK(frame->isLocalRoot());
+    if (Document* document = toLocalFrame(frame)->document()) {
+      if (Fullscreen* fullscreen = Fullscreen::fromIfExists(*document))
+        fullscreen->didExitFullscreen();
+    }
+
+    // Skip over all descendant frames.
+    while (nextFrame && nextFrame->tree().isDescendantOf(frame))
+      nextFrame = nextFrame->tree().traverseNext();
+    frame = nextFrame;
+  }
 }
 
 void FullscreenController::enterFullscreen(LocalFrame& frame) {
   // If already fullscreen or exiting fullscreen, synchronously call
   // |didEnterFullscreen()|. When exiting, the coming |didExitFullscren()| call
   // will again notify all frames.
   if (m_state == State::Fullscreen || m_state == State::ExitingFullscreen) {
     State oldState = m_state;
     m_state = State::EnteringFullscreen;
     didEnterFullscreen();
@@ skipping 36 matching lines @@
   webFrameClient(frame).exitFullscreen();
 
   m_state = State::ExitingFullscreen;
 }
 
 void FullscreenController::fullscreenElementChanged(Element* fromElement,
                                                     Element* toElement) {
   DCHECK_NE(fromElement, toElement);
 
   if (toElement) {
-    DCHECK(Fullscreen::isCurrentFullScreenElement(*toElement));
+    DCHECK(Fullscreen::isFullscreenElement(*toElement));
 
     if (isHTMLVideoElement(*toElement)) {
       HTMLVideoElement& videoElement = toHTMLVideoElement(*toElement);
       videoElement.didEnterFullscreen();
 
       // If the video uses overlay fullscreen mode, make the background
       // transparent.
       if (videoElement.usesOverlayFullscreenVideo() &&
           m_webViewImpl->layerTreeView()) {
         m_webViewImpl->layerTreeView()->setHasTransparentBackground(true);
       }
     }
   }
 
   if (fromElement) {
-    DCHECK(!Fullscreen::isCurrentFullScreenElement(*fromElement));
+    DCHECK(!Fullscreen::isFullscreenElement(*fromElement));
 
     if (isHTMLVideoElement(*fromElement)) {
       // If the video used overlay fullscreen mode, restore the transparency.
       if (m_webViewImpl->layerTreeView()) {
         m_webViewImpl->layerTreeView()->setHasTransparentBackground(
             m_webViewImpl->isTransparent());
       }
 
       HTMLVideoElement& videoElement = toHTMLVideoElement(*fromElement);
       videoElement.didExitFullscreen();
@@ skipping 54 matching lines @@
   // again to ensure the final constraints pick up the latest contents size.
   m_webViewImpl->didChangeContentsSize();
   if (m_webViewImpl->mainFrameImpl() &&
       m_webViewImpl->mainFrameImpl()->frameView())
     m_webViewImpl->mainFrameImpl()->frameView()->setNeedsLayout();
 
   m_webViewImpl->updateMainFrameLayoutSize();
 }
 
 }  // namespace blink