Add goma canary builder

When a new goma client was rolled, it sometimes caused a regression on
chromeos bots. It is because there is no goma canary bot for
build_package, though a simple-chrome goma canary bot was set up.

This patch adds a new builder,
amd64-generic-goma-canary-chromium-pfq-informational.
This bot is something similar to amd64-generic-tot-asan-informational,
but follows more usual configs without hardware tests etc.
The canary version of goma will be installed via cipd later.

BUG=chromium:746816
TEST=Ran bots

Change-Id: Ic8a66fb19499b2ecfb34368795b1462fa502c28b
Reviewed-on: https://chromium-review.googlesource.com/614826
Commit-Ready: Shinya Kawanaka <shinyak@chromium.org>
Tested-by: Shinya Kawanaka <shinyak@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
3 files changed