This patch wants to solve several quirks around the shutdown terminator.
- Use the same shutdown phase definitions in AppShutdown and nsTerminator. This touches quite a few files.
- Ensure that the terminator phase shift is handled before any shutdown observer notifications are sent and reduce its heartbeat duration.
- Add missing phases to the shutdown telemetry.
Please note that this changes the unit of "tick" to 100ms rather than 1s.
As a side effect, we also remove the obsolete "shutdown-persist" context.
While the existing test coverage continues to prove the most important functions, we acknowledge the wish for better test coverage with [[ https://bugzilla.mozilla.org/show_bug.cgi?id=1693966 | bug 1693966 ]].
Differential Revision: https://phabricator.services.mozilla.com/D103626
f6d52040b9