user/test/com/google/gwt/resources/client/gss/resourceUrl.gss

@def THE_DATA_URL resourceUrl('someDataResource');
@def THE_IMG_URL resourceUrl('someImageResource');

.someClass {
    cursor: THE_DATA_URL;
    background-image: THE_IMG_URL;
    cursor: resourceUrl('someDataResource');
    /* @alternate */ background-image: resourceUrl('someImageResource');
}