[2] Add the <iframe allowpaymentrequest> attribute (sideshowbarker著, ) <https://github.com/whatwg/html/commit/af407d47fe17b93b74f12c3538d39a7597acdab2>
[1] Snapshot allowpaymentrequest and allowusermedia attributes (zcorpan著, ) <https://github.com/whatwg/html/commit/b3224a8457e32015153ed91f26b6212e25df1d6b>
[3] Integrate Feature Policy concepts into HTML (clelland著, ) <https://github.com/whatwg/html/commit/78741b7b5471ba213c68a22caff1a53c56d35ce8>