In bug 1013997, Alex is working on loading the DevTools modules in one compartment to save memory. This means they will share globals, and so need to play nicely together. The QR decoder extends Array prototype[1], but there's only one use of this, so it could just be inlined. [1]: http://mxr.mozilla.org/mozilla-central/source/toolkit/devtools/qrcode/decoder/index.js#2568

Once such a cleanup is made, it can be removed from the loader blacklist added in bug 1013997.

The decoder now leaves Array alone and doesn't add any methods to it, so it's safe to share globals with other loader modules. Also, I've changed the window access method back to getMostRecentWindow, since as discussed elsewhere, hiddenDOMWindow does not work on b2g. Try: https://tbpl.mozilla.org/?tree=Try&rev=5eb6c89e8079

Test failures revealed one more source of evil to fix. Try: https://tbpl.mozilla.org/?tree=Try&rev=cb8ee36e2fcb