r route = this.$.selection.routes[newIndex];
          if (!route) return;
          route.navigateTo();
        }.bind(this));
      },

      _routesFromChildren: function() {
        // If we aren't managing a `core-selector`, just use our own children.
        var context = this._managedSelector || this;
        var routes = [];
        for (var i = 0, child; child = context.children[i]; i++) {
          routes.push(this._routeForChild(child));
        }

        return routes;
      },

      _routeFor