util_test MachMessageServer.ReturnCodeNoReply: keep the child alive until the server is done

util_test MachMessageServer.ReturnCodeNoReply: keep the child alive
until the server is done handling its request.

In most tests, this is handled automatically because the client expects
a reply from the server, and waits for this reply. This test is
different because the server does handle the message, but does not send
a reply, so the client does not wait for one. When the child process
exits before the parent has had a chance to inspect the message it
received, the parent will find a dead name where it expects the remote
port to be, causing this test to be flaky based on the outcome of this
race.

The potential for a similar race existed in the
MachMessageServer.ComplexNotDestroyedNoReply test because it also
involved a request without a reply. In that test, the situation was
handled by not allowing the child to exit until signaled to do so by the
parent. The same logic should be used for both no-reply tests.

TEST=util_test MachMessageServer.ReturnCodeNoReply
R=rsesek@chromium.org

Committed: https://chromium.googlesource.com/crashpad/crashpad/+/b77c788543a1b6e8c6862ac8af35948d03ea1eff

[Mark Mentovai, 2014-09-14 05:03:29]

mark@chromium.org changed reviewers:
+ rsesek@chromium.org

[Robert Sesek, 2014-09-15 18:19:38]

LGTM

[Mark Mentovai, 2014-09-15 19:08:31]

Committed patchset #1 (id:1) manually as b77c788 (presubmit successful).