GitLab

Instead build just the targets in chromium.webrtc.

Bonus: remove obsolete tryjob definitions.

Bug: chromium:820041, chromium:808111
TBR: machenbach@chromium.org
No-Try: True
Change-Id: I133593a4e51a5e1dac4d0e24d21601cd553784a0
Reviewed-on: https://chromium-review.googlesource.com/956043Reviewed-by: Patrik Höglund <phoglund@chromium.org>
Commit-Queue: Oleh Prypin <oprypin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542062}