Chrome Version: M68-
OS: Win10 / All that support process priority toggling.

What steps will reproduce the problem?
(1) Have many background tabs (notice in process explorer they're running at background OS priority)
(2) ctrl+shift+Q to close Chrome

What is the expected result?
Background processes are foregrounded before being asked to shutdown

What happens instead?
The browser process pings beforeunload handlers and waits for each renderer. Some of those may take "forever" to unwind if the OS has other things to do.