Continuing on from 0002366, we would like to ask for an implementation for Display::Close() for iOS (ie. UIKitDisplay) as well. This is only needed for test apps, but currently we do not have a way to exit from UIKitDisplay::EnterMessageLoop() during automated testing. Most alternatives to Display::Close() led us to crashing the app which triggers Apple's Crash Reporting UI, less than ideal for CI.

Apple has provided an example implementation of what changes you should make to the current usage of [[NSRunLoop currentRunLoop] run] here that allows exiting:
https://developer.apple.com/documentation/foundation/nsrunloop/1412430-run?language=objc

Given the above example, a call to Display::Close() would then probably set shouldKeepRunning = NO, hopefully allowing us to return from UIKitDisplay::EnterMessageLoop() to shutdown our testing without needing to crash the app.