Get sheriff-o-matic data from auto-sheriff.appspot.com.

This moves the logic of which tests are failing and their
regression ranges to the server. This makes the tool much
faster to load. Having it on the server makes it so that
multiple tools can use this data.

Also, the data on the server has all the data we need for
non-layout test steps, so extending sheriff-o-matic will
be very easy once we have this in place.

NOTRY=true
R=abarth@chromium.org

Review URL: https://codereview.chromium.org/402603007

git-svn-id: svn://svn.chromium.org/blink/trunk@178597 bbb929c8-8fbe-4397-9dbb-9b2b20218538