GitLab

This CL adds 3 new bots:
* Linux Ozone Tester (Wayland) on chromium.linux
  - Triggered by linux-ozone-rel
  - All tests have --ozone-platform=wayland
* Linux Ozone Tester (X11) on chromium.linux
  - Triggered by linux-ozone-rel
  - All tests have --ozone-platform=x11
* linux-ozone-x11-and-wayland-rel
  - Trybot that is a combination of the above 2 bots and
    linux-ozone-rel
  - Eventually, linux-ozone-rel (trybot) will inherit this
    bot's config and this bot will be removed.

Requires tools/build change:
https://chromium-review.googlesource.com/c/chromium/src/+/1962128

BUG=1043896
R=estaab

Change-Id: I4b3575526ba485f80d2fb03cfed677aa943b47b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2032518
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Aaron Gable <agable@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738727}