It seems that Debian has stopped updating Chromium for Jessie.
Last update was in February 2017 for Chromium 57.
Stretch has the current stable version, which is Chromium 61.
This task is for making Chromium 59 (or newer) the default for Jenkins jobs running Debian Jessie in Nodepool.
This task is for making Chromium 59 (or newer) the default for Jenkins jobs. It will be implemented with a Docker container running stretch.
Mainly for the new Headless Chrome option that was introduced in Chrome 59 release (via the --headless cli option).