The newest Chrome Beta channel release includes new ES6 features and a number of updates to existing APIs. Unless otherwise noted, changes described below apply to Chrome for Android, Windows, Mac, Linux and Chrome OS.
Improved notification capabilities
Chrome 42 allowed users to opt in to receive push notifications from sites even after the page is closed. Sites may now use getNotifications to observe which of their notifications are still being displayed, and Notification.data to store a payload with a notification so they can determine which notification was clicked.