According to signage in front of the building and the longueuil.quebec website, this is actually named Bibliothèque Muriel-Anne-Brown now. Unfortunately I don't know if the official English version is just "Muriel-Anne-Brown Library" or something slightly different...and the paper with the hours on the door refers to it as "Bibliothèque de Greenfield Park"

Needs to be resurveyed, probably by asking one of the librarians.