Add scarlet builder config

BUG=None
TEST=None

Change-Id: I7787e086317fd680dae870dba48983ccb2c9a944
Reviewed-on: https://chromium-review.googlesource.com/430192
Commit-Ready: Philip Chen <philipchen@chromium.org>
Tested-by: Philip Chen <philipchen@chromium.org>
Reviewed-by: Ningning Xia <nxia@chromium.org>
3 files changed