GitLab

Relands parts of https://chromium-review.googlesource.com/c/chromium/src/+/1088754

headless tests can't run on the memory waterfall yet because of bug 844865.
This adds them to the linux clang tot bots. (They already run on the mac and win
clang tot bots, and on the main waterfall.)

TBR=kbr

Bug: 843511,843732
Change-Id: Iec20d59c425b9d847fa2d3f076f907b69ba0e795
Reviewed-on: https://chromium-review.googlesource.com/1093051Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565640}