We can switch the child process to be launched via the multi-process-test
macro, but the bulk of the work will be actually capturing the CHECK
crashes; once we have that we can also enable GTEST death-tests if we want.

Looks like we can crib from Fuchsia's ulib unit-test crash handler
implementation (see
https://github.com/fuchsia-mirror/magenta/blob/82b9b705e91b798f35ed1daf831ca2bcad6689bd/system/ulib/unittest/crash-handler.c#L317
).

Punting this back to Assigned, since it's going to take more work than just updating process-launching. We'll want to set up an "exception port" for the crashy child process to trap it exploding, as per: https://fuchsia.googlesource.com/magenta/+/master/docs/syscalls/task_bind_exception_port.md

Assigning to fdegans@, who is adding the 

Actually assigning myself. wez@ got captured by Candlejack before he could finish his me

I'm looking into this test and I'm a bit confused by what it does. It seems it is checking that the platform exception handling is working properly. I'm not sure what part of Chromium is under test here.

Re #6: The test is intended to verify that CHECK()s at different call-sites can be distinguished, rather than all being folded into a single set of instructions that the CHECK sites jump to on failure, IIUC.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a2a5386474feb62d5b8a84244b8657f09209fb22

commit a2a5386474feb62d5b8a84244b8657f09209fb22
Author: Fabrice de Gans-Riberi <fdegans@chromium.org>
Date: Fri Jun 08 18:04:26 2018

Implement LoggingTest.CheckCausesDistinctBreakpoints for Fuchsia.

Bug:  753851 
Change-Id: Id457ec00228fe6a5592719c47491087e979bd5b2
Reviewed-on: https://chromium-review.googlesource.com/1077600
Commit-Queue: Fabrice de Gans-Riberi <fdegans@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Scott Graham <scottmg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565682}
[modify] https://crrev.com/a2a5386474feb62d5b8a84244b8657f09209fb22/base/logging_unittest.cc