Git commits in Moodle 3.7.x by Sam Hemelryk

commit d66d85a4d7e8f748456dc2794720ff5dedc221f3
Author: Sam Hemelryk <sam.hemelryk@totaralearning.com>
Date:   Tue, 15 Oct 2019 12:28:25 +0800
Tag:    v3.7.5

MDL-67175 mod_scorm: sync XHR requests use sendBeacon when available