You may have trouble finding John under the above spelling. The actual surname is Warrin as used in the Vital Records of Watertown books. Subsequent family also used the Warrin spelling for at least 5 generations. It is obviously the spelling that the family intended as it is used in wills and deeds as well as vital records. It has been the more recent generations of researchers who have decided to change it to the common spelling which is not accurate. Imagine if someone was to change your surname to a spelling that they preferred and not what you intended.
See the bottom of this page: http://ma-vitalrecords.org/MA/Middlesex/Watertown/Images/WatertownV1_029.shtml