UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36

Steps to reproduce the problem:
1. Have a push subscription on a browser on a computer
2. Have the computer sleep
3. Send push notification(s) to that browser, verify that they are accepted by GCM/FCM
4. Wake the computer later, and observe when the notification(s) are shown

What is the expected behavior?
Push notifications are displayed as soon as possible after the computer is woken and/or Chrome is used. Push notifications are never shown if the expiration time has passed.

What went wrong?
Even though the browser is in use, push notifications may not be displayed until a new notification is shown (for example, we see that Google Calendar notifications 'wake Chrome up' and a number of push notifications are all displayed together.

We also have reports of push notifications being shown *after* the expiration time has passed. We are attempting to verify this and produce some sort of test.

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 54.0.2840.98  Channel: stable
OS Version: OS X 10.12.1
Flash Version: Shockwave Flash 23.0 r0

We're flagging this up now because we're getting reports that notifications for Black Friday sales, sent with expiration times 24 hours after sending, were shown to end users on Tuesday morning.