GitLab

This should reduce review latency/friction of making these changes.

Additionally, expanded the README to mention the GN build flag
fieldtrial_testing_like_official_build which can be used to disable
the testing config.

Bug: None
Change-Id: I5995bdf59a6a02640a7c9119830e0be1d3a33316
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2537098Reviewed-by: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Weilun Shi <sweilun@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Alexei Svitkine <asvitkine@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833023}