Steps to reproduce: 1. go to https://vimeo.com/225249697 2. tap to start the video 3. enter fullscreen 4. exit fullscreen by tapping the X icon Both the WebKit media controls and the Vimeo custom controls appear sometimes, but not always. This is due to https://bugs.webkit.org/show_bug.cgi?id=174626, where the "webkitfullscreenchange" event isn't fired when entering or exiting fullscreen, so depending on when the "play" or "pause" event fires, the ControlsVisibilitySupport object may think that the controls are still in fullscreen and not get an event that we exited fullscreen.
<rdar://problem/33301005>
Created attachment 315794 [details] Patch
Comment on attachment 315794 [details] Patch LGTM
Comment on attachment 315794 [details] Patch provisional r+
Created attachment 315814 [details] Patch for landing
Comment on attachment 315814 [details] Patch for landing Clearing flags on attachment: 315814 Committed r219621: <http://trac.webkit.org/changeset/219621>
All reviewed patches have been landed. Closing bug.