[1] 1311807 - Some images and media players delayed for minutes (2017-10-28 22:39:57 +09:00) <https://bugzilla.mozilla.org/show_bug.cgi?id=1311807>

[2] webappsec-mixed-content/proposed-level-2-roadmap.md at master · mikewest/webappsec-mixed-content (2017-10-28 22:40:23 +09:00) <https://github.com/mikewest/webappsec-mixed-content/blob/master/proposed-level-2-roadmap.md>