Seen while working on bug 1519335:

[task 2020-05-27T13:02:41.718Z] 13:02:41     INFO - PID 17503 | 1590584561715	Marionette	DEBUG	0 -> [0,195,"WebDriver:SwitchToFrame",{"id":null}]
[task 2020-05-27T13:02:41.719Z] 13:02:41     INFO - PID 17503 | ** start listener switch to frame
[task 2020-05-27T13:02:53.777Z] 13:02:53     INFO - PID 17503 | DEBUG: Adding blocker SessionFile: Finish writing Session Restore data for phase profile-before-change
[task 2020-05-27T13:02:53.778Z] 13:02:53     INFO - PID 17503 | DEBUG: Completed blocker SessionFile: Finish writing Session Restore data for phase profile-before-change
[task 2020-05-27T13:04:01.089Z] 13:04:01     INFO - TEST-UNEXPECTED-TIMEOUT | /webdriver/tests/new_window/new_tab.py | expected OK

When Firefox is going down we should never call into the listener or at least make sure to resolve the appropriate Promise to never cause a hang in Marionette, and probably also Firefox during a shutdown.

Actually I will go ahead and just disable those tests for ASAN on linux1804 for now. We can get back to this later. Maybe the Fission work will make it work anyway.

The framescript code in Marionette is gone, and the JSWindowActor code perfectly handles this case now.