Feature policy violations should produce reports, sent through the Reporting API, and visible to Reporting Observers.
The exact semantics of what a 'violation' is will be up to individual features, so this may end up as an umbrella bug for all of those as well.
Initially, we want first-party reporting only -- that is, reports for violations within a given frame are sent only to the endpoints specified by *that* frame's Report-to header. Parent frames, either same- or cross-origin, do not receive reports generated by their children.
Comment 1 by bugdroid1@chromium.org
, Aug 13