Can't happen til after the prod freeze, sometime next year.

back into the trooper queue now that we're out of the prod freeze.

Taking as a trooper.

Following https://bit.ly/chromium-build-naming, I'm thinking the name of the new try bot will be "linux-trusty-webkit-msan-rel". Since the original builder is compile+tests, this trybot will directly mirror this one single builder.

Curious finding: WebKit Linux Trusty MSAN used to be in two masters:

chromium.memory: https://cs.chromium.org/chromium/build/scripts/slave/recipe_modules/chromium_tests/chromium_memory.py?l=214&rcl=85e8396b39da493e307e124b1de776e08d8e8a02 (still used by the LUCI bot)

chromium.webkit: https://cs.chromium.org/chromium/build/scripts/slave/recipe_modules/chromium_tests/chromium_webkit.py?l=103&rcl=1de517d906f2b1e8b263ecb3d91ac3d986efe447 (looks like dead code now).

First CL in a series: https://crrev.com/c/1403836 (adding a mirrored trybot to the recipe).

Next, I'll allocate hardware in chromium-swarm to run the bot (will try to find a shared pool with other optional bots, if possible), and then add the builder to cr-buildbucket.cfg. I believe this should do it.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/build/+/b0477f206bed1311b62bf27b8561ad5595571d12

commit b0477f206bed1311b62bf27b8561ad5595571d12
Author: Sergey Berezin <sergeyberezin@google.com>
Date: Thu Jan 10 00:27:27 2019

[chromium_tests] Add trybot linux-trusty-webkit-msan-rel

Bug: 917346
Change-Id: Iffe3ecda404d68b70af2c00a59cc05a429af81de
Reviewed-on: https://chromium-review.googlesource.com/c/1403836
Auto-Submit: Sergey Berezin <sergeyberezin@chromium.org>
Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: Sergey Berezin <sergeyberezin@chromium.org>

[modify] https://crrev.com/b0477f206bed1311b62bf27b8561ad5595571d12/scripts/slave/recipe_modules/chromium_tests/trybots.py

The remaining steps:
https://crrev.com/i/782819 - configuring hardware for the bot
https://crrev.com/c/1406175 - adding the builder declaration (the final step).

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/infradata/config/+/651fffb73fdf28a11a522a28aa27261c66ec621a

commit 651fffb73fdf28a11a522a28aa27261c66ec621a
Author: Sergey Berezin <sergeyberezin@google.com>
Date: Thu Jan 10 23:57:01 2019

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6e26f8b00bd4ea2d30197dfffbb3a2611680b666

commit 6e26f8b00bd4ea2d30197dfffbb3a2611680b666
Author: Sergey Berezin <sergeyberezin@google.com>
Date: Fri Jan 11 01:22:42 2019

[cr-buildbucket] Add an optional trybot linux-trusty-webkit-msan-rel

Bug: 917346
Change-Id: I8d9d323c76dc57ada8d367f7c323296aee7afd22
Reviewed-on: https://chromium-review.googlesource.com/c/1406175
Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: Sergey Berezin <sergeyberezin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#621844}
[modify] https://crrev.com/6e26f8b00bd4ea2d30197dfffbb3a2611680b666/infra/config/global/cr-buildbucket.cfg

This should be done. Tentatively marking as fixed; please reopen if the new trybot isn't working. 

Looks like some configs are still missing: https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux-trusty-webkit-msan-rel/1.