Wikimedia Bugzilla is closed!

You have the code: 
// Marker element for adding dynamic styles
var $marker = $( 'head meta[name=ResourceLoaderDynamicStyles]' );

You should instead have: 
var $marker = null and then use this.getCssMarker() or getCssMarker() and locally cache the selector so you can lazy initialize the target ( and do things like add the target to the page if its missing )

something like: 

// Marker element for adding dynamic styles
var $marker = null ; // lazy init
var getMarker = function(){
if( $marker ){
	return $marker;
}
$marker = $( 'head meta[name=ResourceLoaderDynamicStyles]' )
if( ! $marker.length ){
	$marker = $( '<meta />').attr( 'name', 'ResourceLoaderDynamicStyles' )
		  .appendTo( 'head' );
	}
return $marker;
};