function _reloadUserPrefs(rootDir) {
        var prefsDir = brackets.app.getApplicationSupportDirectory() + "/";
        if (prefsDir.indexOf(rootDir.fullPath) === 0) {
            manager.fileChanged(userPrefFile);
            stateManager.fileChanged(userStateFile);
        }
    }
Promises to add scopes. Used at init time only.
@private
@type {Array.<$.Promise>}