• Message that gets passed to service worker scope on postMessage
  • An iframe sizing operation.
  • Channels to allow service worker manager to communicate with constellation and resource thread
  • Entities required to spawn service workers


  • Whether a DOM event was prevented by web content
  • The kind of error the job promise should be rejected with.
  • Messages sent from Job algorithms steps running in the SW manager, in order to resolve or reject the job promise.
  • Jobs are resolved with the help of various values.
  • Messages from the layout to the constellation.
  • A log entry reported to the constellation We don’t report all log entries, just serious ones. We need a separate type for this because LogLevel isn’t serializable.
  • Messages outgoing from the Service Worker Manager thread to constellation
  • Messages from the script to the constellation.
  • Messages sent to Service Worker Manager thread