Generally when you cannot find information on very small or insignificant placenames, you research nearby larger places (because events may apply to a larger area) or the next placename in the hierarchy. You may even get lucky and find passing references to your main interest that weren't directly searchable.
Angloh (var. Angerloh) is officially part of Kirchham, so searching the history of that city would be first. Also Landkreis Passau and its predecessors and Bavaria.
Don't restrict yourself to on-line searches. Check library and archive catalogues for hard-copy histories and digitized materials that may accessible but not searchable.
Remember that much more will be available in the local language and in the actual vicinity. "Bayerischer Landesverein für Familienkunde e.V." (BLF)" has publications and forums that may be relevant. A Worldcat search returns, among others, "Kirchhamer Heimatbuch: auf der Grundlage der Chronik von Kirchham bis 1945" and "1200 Jahre Kirchham : Zu d. Feierlichkeiten vom 2.-10. Juli 1977." At GoogleBooks: Statistische Beschreibung des Bisthums Passau, 1867, p. 71 says that the parish of Kirchham includes the village of Kirchham (41 houses with 325 inhabitants), and, outside Kirchham, among others, the place "Angerloh" (1 house with 9 inhabitants).
Angloh may always have been small, and a local name for a crossroads or a farmhouse. Or it may have been a thriving village or town before war or pestilence depopulated it (a frequent occurrence in Bavaria). If the former, you may never get much additional information.
Also, by definition, a surname referencing a past residence was acquired AFTER moving elsewhere. Depending on the era that occurred, there may not be a record documenting it. If the surname is actually a farm-name, then any family living there may have taken on (or been known as) that name, without necessarily being related to the previous residents.