code: function updateTabOrder () {
      var selectedItem   = ctrl.tabs[ ctrl.selectedIndex ],
          focusItem      = ctrl.tabs[ ctrl.focusIndex ];
      ctrl.tabs          = ctrl.tabs.sort(function (a, b) {
        return a.index - b.index;
      });
      ctrl.selectedIndex = ctrl.tabs.indexOf(selectedItem);
      ctrl.focusIndex    = ctrl.tabs.indexOf(focusItem);
    }
docs: Re-orders the tabs and updates the selected and focus indexes to their new positions.
  This is triggered by `tabDirective.js` when the user's tabs have been re-ordered.