This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.
PermissionSettings object you can use to get and set permissions of all apps on the system.
var permissions = window.navigator.mozPermissionSettings;
navigator.mozPermissionSettings is a
Not part of any specification.