UIWebView Keep Video Playing After Exiting Fullscreen

Question

In our app, we want to be able to keep a video playing after the user has quit fullscreen mode. The video is a YouTube one, thus it uses YTPlayerView framework, which uses UIWebView and iframe player to play the video.

As you have probably noticed, in iOS 11, when a web video enters fullscreen, there is only one 'X' button at the upper left corner to quit fullscreen and pause the video, instead of two(one 'Done' at the top and one arrow at the bottom) like before.

I have been able to get a UIWindowDidBecomeHidden notification when the fullscreen quits, and play the video programmatically, but then I realize that if the user has already paused the video manually before quitting fullscreen, it will start playing nonetheless when he/she quits. However, adding something in the YTPlayerDelegate won't do much since the system will pause the video(sending the stateDidChange delegate) before sending the notification, so I cannot differentiate between a manual pause when fullscreen and a system pause when quitting fullscreen.

My question is, is there a way to detect leaving fullscreen action before the system pauses the video? If not, is there a native API to have the player keep playing? If not either, is this feature possible? How would I achieve it? Thanks.