Declarative Web Push: Add "defaultAction" member to Notification and NotificationOptions. This is necessary for JavaScript to construct new notifications in a `pushnotification` event handler, and is a nice optional for JavaScript handling legacy `push` events.
<rdar://problem/115938949>
Pull request: https://github.com/WebKit/WebKit/pull/18124
Committed 268402@main (72258dba1b79): <https://commits.webkit.org/268402@main> Reviewed commits have been landed. Closing PR #18124 and removing active labels.
Committed 268402@main (None): <https://commits.webkit.org/268402@main> Reviewed commits have been landed. Closing PR #18124 and removing active labels.