(FFOS Gecko)

MOZ_FINAL:

http://whereswalden.com/2011/11/26/introducing-moz_final-prevent-inheriting-from-a-class-or-prevent-overriding-a-virtual-function/

MOZ_OVERRIDE:

http://whereswalden.com/2011/11/16/introducing-moz_override-to-annotate-virtual-functions-which-override-base-class-virtual-functions/