In #39, we've discussed the merits of sharing method names for the {get|has}Permission(Stat{e|us}?) method with the Push, Notification, and Permissions APIs.

Should we also be aligning the enum values values with those APIs? Push and Permissions both use granted, denied, and prompt, while Notifications and BackgroundSync have default, denied, and granted.

If we're eventually moving to the Permissions API, then maybe we should be using it's enums. I think that 'prompt' is useful to have, and makes more sense than default for BackgroundSync. ('default' is a nebulous concept anyway, and if the user agent reserves the right to change what the default behaviour is, then it doesn't tell the app developer anything at all. 'prompt' is at least explicit about what will happen.)