1. Beacon API

    Allows data to be sent asynchronously to a server with `navigator.sendBeacon`, even after a page was closed. Useful for posting analytics data the moment a user was finished using the page.

  2. fence api: setreporteventdataforautomaticbeacons

  3. fence api: setreporteventdataforautomaticbeacons: separate `reserved.top_navigation_start` and `reserved.top_navigation_commit` `eventtype` values