mozilla/pdf.js — pull request #5191 by nnethercote (2014-08-15 02:11:28+00:00)
Title: Right-size the array in getSampleArray().

This allows the JS engine to do a better job of allocating the right
number of elements for the array, avoiding some resizings. For the PDF
in #2504, this avoids 100s of MiBs of allocations in Firefox.