mozilla/pdf.js — pull request #4966 by nnethercote (2014-06-18 04:58:33+00:00)
Title: Add ChunkedStream.ensureByte().

This new function is much faster than ensureRange(pos, pos+1), which is a very
common case.

This speeds up the rendering of some test cases (including the Tracemonkey
paper) by 4--5%.