1. Open Play Music on a system with 2 monitors on Linux (may repro on some other platforms as well) and play some music.
2. Move the window such that it's displayed on both screens (one side on one screen, another one on the other screen).
3. Try closing the tab. Observe "Do you want to leave this site" prompt not positioned correctly

See attached screenshot. It looks like the dialog is centered in the part of the window that's on the main screen. If only small part of that window is on the main screen then the dialog may not be fully visible. This leads to a surprising behavior as the prompt may be hard to notice and it's modal (i.e. I can't even switch to another tab).

Chrome version Version 64.0.3278.0 (Official Build) dev (64-bit)
 

Deleted: close-prompt-screenshot.png 523 KB

	close-prompt-screenshot.png 523 KB View Download