Re: [PATCH v3 1/2] user32/tests: Wait for parent thread to complete before checking messages.

[Rémi Bernon]

There's still a timeout related failure around this test, but on Windows 
this time...:

* https://testbot.winehq.org/JobDetails.pl?Key=59643#k210
* https://testbot.winehq.org/JobDetails.pl?Key=59645#k213