GitLab

https://chromium.googlesource.com/infra/luci/luci-py/+/master/appengine/swarming/doc/Bot.md#graceful-termination_aka-the-sigterm-and-sigkill-dance

test_env.py already has support for this, but it looks like a lot
of the scripts aren't using it. One reason for that could be that
there wasn't a run_command function there yet. I added a simple
run_command function, and made a bunch of scripts use it.

This should fix up all the test suites that use common.py's
functions to run subprocesses including:
 - run_telemetry_as_googletest.py
 - run_chromedriver_test.py
 - telemetry_gpu_unittests.py
 - telemetry_perf_unittests.py
 - telemetry_unittests.py
And many more!

Also delete common's run_integration_test function since no
one is using it.

Bug: 921662, 910584
Change-Id: If670e1b5725e3a7dcfda471b7141d47c73c5ef82
Reviewed-on: https://chromium-review.googlesource.com/c/1461512Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Marc-Antoine Ruel <maruel@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Auto-Submit: Caleb Rouleau <crouleau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634740}