mozilla/pdf.js — pull request #757 by brendandahl (2011-11-04 16:33:41+00:00)
Title: Hash test files to make sure they haven't changed.

As Bill so eloquently put it, you don't want the yard stick changing while you're trying to measure something. This also resolves the problem I've run into several times where I re-download the test files and one of them doesn't download properly.