CONSOLE ERROR: Mixed Content: The page at 'https://web-platform.test:8444/mixed-content/audio-tag/http-csp/same-host-http/top-level/keep-scheme-redirect/optionally-blockable/opt-in-blocks.https.html' was loaded over HTTPS, but requested an insecure video 'http://web-platform.test:8001/mixed-content/generic/expect.py?redirection=keep-scheme-redirect&action=purge&key=9cd81086-200e-4fa0-b506-b2967f28affd&path=%2Fmixed-content&content_type=audio/wav'. This request has been blocked; the content must be served over HTTPS.
