UserAgent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36

Steps to reproduce the problem:
As per specs (https://notifications.spec.whatwg.org/#replacing-a-notification), when an old notification is replaced by a new one (when both notifications have same, non-empty tag), the old notification should be removed from the list of notifications and the new one placed in its spot. However this is not happening.

To reproduce it (in the service worker context):

    self.registration.showNotification('A', { tag: 'abc' })
      .then(() => self.registration.getNotifications({ tag: 'abc' }))
      .then(notificationsList => {
        console.log(notificationsList); // [ NotificationA ]
        return self.registration.showNotification('B', { tag: 'abc' });
      })
      .then(() => self.registration.getNotifications({ tag: 'abc' }))
      .then(notificationsList => {
        console.log(notificationsList); // [ NotificationB, NotificationA ]
        return self.registration.showNotification('C', { tag: 'abc' });
      })
      .then(() => self.registration.getNotifications({ tag: 'abc' }))
      .then(notificationsList => {
        console.log(notificationsList); // [ NotificationC, NotificationB, NotificationA ]
      })

What is the expected behavior?
The result of self.registration.getNotifications({ tag: 'abc' }) should only contain the latest Notification, which was to replace the old one.

What went wrong?
To "prevent" this behavior in code, before calling the self.registration.showNotification(), you need to explicitly walk through the notificationsList for that tag and call .close() on every Notification object.

The Notification is only ever removed from the notifications list when the person explicitly closes the notification by swiping it away or clicking [x] button on the notification (in that case, the .close() is called implicitly), or when the code itself calls .close() on a Notification.

Did this work before? No 

Chrome version: 51.0.2704.103  Channel: stable
OS Version: 10.0
Flash Version: Shockwave Flash 22.0 r0