This feature enables users to get / set a Request's referrer policy which affect's the "Referer" HTTP header.
Docs: https://hacks.mozilla.org/2016/03/referrer-and-cache-control-apis-for-fetch/ https://developer.mozilla.org/en-US/docs/Web/API/GlobalFetch/fetch
Samples: https://googlechrome.github.io/samples/fetch-api/fetch-referrer-policy.html