Mozilla SpecialPowers testing extension, extracted as reusable .xpi file.
Download: https://github.com/downloads/humphd/SpecialPowers/SpecialPowers.xpi (pre-built XPI)
Copy the SpecialPowers.xpi into your Firefox browser to install the extension. See https://developer.mozilla.org/en/SpecialPowers for details on using it. NOTE: window.SpecialPowers will exist when the extension is installed.
- Add back in support for http://mxr.mozilla.org/mozilla-central/source/testing/mochitest/MockFilePicker.jsm and package it with the extension (currently removed).