Run content_browsertests on swarming on the cast bots.

content_browsertests takes almost 7 minutes to run and is currently on the
critical path of the bot since it's not swarmed, so this should reduce
the cycle time of cast_shell_linux by almost 7 minutes.

Bug: 843511,861843
Change-Id: I95dc87ca2b844b2bf0363b4a8b1915aeaed30938
Reviewed-on: https://chromium-review.googlesource.com/1129042
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575360}
2 files changed