LayoutTests/imported/w3c/web-platform-tests/feature-policy/resources/feature-policy-usb.html

<script>
'use strict';

Promise.resolve().then(() => navigator.usb.getDevices()).then(devices => {
  window.parent.postMessage({ enabled: true }, '*');
}, error => {
  window.parent.postMessage({ enabled: false }, '*');
});
</script>