Assuming you're talking about web push notifications in general and Chrome for Android it's super easy and exactly the same as Chrome for Windows & OSX:
- When on the site in question just tap the padlock/favicon in the URL bar, tap "site settings" and then you can see the permissions granted and change them as you want to.
- Alternatively, you can get to the same "site settings" screen directly from any web push notification in your Android notification panel simply by expanding the notification in the usual way and selecting "settings", which takes you to the "site settings" screen as before.
So if revoking from any page on the site and from any notification pushed by the site isn't straightforward enough then what do you propose instead?
- When on the site in question just tap the padlock/favicon in the URL bar, tap "site settings" and then you can see the permissions granted and change them as you want to.
- Alternatively, you can get to the same "site settings" screen directly from any web push notification in your Android notification panel simply by expanding the notification in the usual way and selecting "settings", which takes you to the "site settings" screen as before.
So if revoking from any page on the site and from any notification pushed by the site isn't straightforward enough then what do you propose instead?