Chrome Version: 69.0.3451.0
OS Version: 10757.0.0

What steps will reproduce the problem?
1. Create a drawing in Keep Chrome app (it currently gets a single-buffered HW underlay, with tearing when you pan)
2. Open Crostini Terminal.app
3. Launch GIMP via Terminal

What is the expected result? GIMP opens in foreground, Keep remains normal

What happens instead of that? Part of Keep canvas turns black