Alert for E10S_STATUS (Histogram Regression Detector) on 2016-10-20

[telemetry-alerts at mozilla.com]

Alert details: http://alerts.telemetry.mozilla.org/index.html#/detectors/1/metrics/1719/alerts/?from=2016-10-20&to=2016-10-20

Changeset for 20161020030211: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=90d8afaddf9150853b0b68b35b30c1e54a8683e7&tochange=99a239e1866a57f987b08dad796528e4ea30e622