This study will test any good and bad effects of the study drug called enzalutamide. Enzalutamide could shrink the cancer but it could also cause side effects. Researchers hope to learn if the study drug will shrink the cancer by at least 30% compared to its present size, in at least 1 out of 5 patients. Enzalutamide is not FDA approved to treat salivary gland cancer, but it has already been FDA-approved to treat other cancers.