The allowed values of Notification.requestPermission() differ between spec and implementations

[saschanaz]

https://notifications.spec.whatwg.org/#dom-notification-requestpermission

1. Let permissionState be the result of requesting permission to use "notifications".

And the Permissions term: https://w3c.github.io/permissions/#dfn-request-permission-to-use

This algorithm returns either "granted" or "denied".

But in reality the static function can return "default" too:

1. Firefox returns "default" when the function is called without transient user activation
2. Chrome returns "default" when the prompt is closed by clicking X button

(Safari returns "denied" when without transient user activation, but that's weird because it disagrees with Notification.permission then.)

Should we have an optional step that covers transient user activation #108 ? The Chrome case should probably be covered in Permissions spec instead.

[annevk]

Yeah, that sounds reasonable.

It seems that Permissions should be able to return "prompt" as well (e.g., when the user dismisses the prompt in that manner), which we'd then translate to "default".

cc @johannhof @marcoscaceres