Added CQ config to skia repo

This must land in sync with https://chromereviews.googleplex.com/204307013 and
revert in sync.

R=rmistry@chromium.org, tandrii@chromium.org
NOTRY=true
NOTREECHECKS=true
BUG=chromium:471767

Review URL: https://codereview.chromium.org/1153093004
7 files changed