GitLab

This is a builder that will build instrumented versions of chromium
gtests on Mac, run them on Mac 10.13 no-gpu bots and upload code
coverage reports to the coverage dashboard.

Later changes will include non-gtest tests and tweak sharding parameters
for this configuration.

R=sajjadm,nodir,liaoyuke

Bug: 1017486
Change-Id: Ie2168653ede5e37498ac9cf62e54a29883173b1f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1877604Reviewed-by: Aaron Gable <agable@chromium.org>
Reviewed-by: Yuke Liao <liaoyuke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710084}