mozilla/pdf.js — pull request #5014 by Snuffleupagus (2014-06-27 09:35:06+00:00)
Title: A few small font optimizations

While fixing various font bugs, I've found some unnecessary uses of the `in` operator in fonts.js.
The changes in this PR are obviously micro optimizations, but given that `in` is *much* slower than a comparison with `undefined` a think that changing this makes sense.