Ticket #23560: 23560.20.diff

src/wp-includes/js/media-views.js

@@ -304 +304 @@
                         this._state = id;
                         this.state().trigger('activate');
 
+                        // Focus the close button for better accessibility
+                        $( '.media-modal' ).find( 'a.media-modal-close' ).focus();
+
                         return this;
                 },