onExitFullscreen property
Event fired when the current page has exited full screen mode.
Official Android API: https://developer.android.com/reference/android/webkit/WebChromeClient#onHideCustomView()
Official iOS API: https://developer.apple.com/documentation/uikit/uiwindow/1621617-didbecomehiddennotification
Implementation
final void Function(InAppWebViewController controller)? onExitFullscreen;