After the glass refactoring in JDK-8325379, a portion of the full-screen overlay window is transiently visible in the lower right of the window as it is animating from full screen size to normal size before it closes. See the attached screen shot.

To reproduce this bug, run the following on macOS from a local build of the metal sandbox branch:

1. java -cp apps/toys/Hello/dist/Hello.jar hello.HelloFullscreen
2. Quickly (before the overlay banner disappears) click on the "Close" button.
3. BUG: after the window has animated from full-screen to normal size, and before the window actually closes, you will see a portion of the overlay in the lower right of the window.

This reproduces on all pipelines (MTL, ES2, SW) after the glass refactoring.