~canonical-sysadmins/wordpress/4.7.2

                                        // Returns a jQuery object containing the menu element.

                                                .removeAttr( 'tabindex' ) // Remove the `tabindex=0` attribute added by jQuery UI.

                                                /*

                                                 * Looks like Safari and VoiceOver need an `aria-selected` attribute. See ticket #33301.

                                                 * The `menufocus` and `menublur` events are the same events used to add and remove

                                                 * the `ui-state-focus` CSS class on the menu items. See jQuery UI Menu Widget.

                                                 */

                                                .on( 'menufocus', function( event, ui ) {

                                                        ui.item.attr( 'aria-selected', 'true' );

                                                })

                                                .on( 'menublur', function() {

                                                        /*

                                                         * The `menublur` event returns an object where the item is `null`

                                                         * so we need to find the active item with other means.

                                                         */

                                                        $( this ).find( '[aria-selected="true"]' ).removeAttr( 'aria-selected' );

                                                });