1749687 - Handle child processes better in GeckoProfiler gtests

Status: NEW

(Core :: Gecko Profiler, task, P3)

Description

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

As found in bug 1749606, the GeckoProfiler.* gtests actually start/stop the profiler in any child process that may be present at the time!

However, we don't do anything to really tests the profiler running in child processes, so it's wasting resources there. Though it may have the side benefit of sometimes revealing issues during development, like in bug 1749606.

This could even explain some intermittent bugs, because we don't wait for the profiler to stop in child processes before restarting it in another test.

So we may want to consider:

• Having a way for most gtests to only start/stop the profiler in the current process. This could probably be done with the "pid:<current process pid>" filter.
• Adding some tests that properly exercise the profiler in child processes. But this may overlap with existing xpcshell/mochitests?