ing) {
        this.__onNextAnimationFrame(this.refit);
      }
    },

    /**
     * Will call notifyResize if overlay is opened.
     * Can be overridden in order to avoid multiple observers on the same node.
     * @protected
     */
    _onNodesChange: function() {
      if (this.opened && !this.__isAnimating) {
        // It might have added focusable nodes, so invalidate cached values.
        this.invalidateTabbables();
        this.notifyResize();
      }
    },

    /**
     * Will set first and l