I know this post was some time ago, but I, too, have a great-grandfather named Bartholomew Cronin, born in Ireland, emigrated to Canada in the late 1880s and became Chief Inspector of Police in Toronto. His son (my grandfather), James Francis Cronin, served in WWI, then came to America and was one of the founding members of Fanny Farmer Candy Company with Frank O'Connor. It's a stretch to think they were the same person, but have you found out anything else about your great-grandfather?