Whether a DOM event was prevented by web content
https://html.spec.whatwg.org/multipage/#replacement-enabled
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.
https://w3c.github.io/ServiceWorker/#dfn-job-type
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