Git commits in Moodle 3.9.0 by Brendan Cox

commit 86b082cece4953893d5d18ee173882fc28d5dd50
Author: Brendan Cox <brendan.cox@totaralearning.com>
Date:   Wed, 02 Oct 2019 06:35:31 +0800
Tag:    v3.9.0-beta

MDL-67175 session: set SameSite=None for Chrome 78 and above