The original OS X cubeb backend (AudioQueue) revealed what appears to be an OS bug resulting in stream deadlocks.
This cubeb backend uses the older AudioUnit API that we already use in sydneyaudio. This backend does not yet implement requests for higher latency via cubeb_stream_init, but this may be added in the future.
Created attachment 612085 [details] [diff] [review]
Note: this code was not actually enabled due to a missing patch chunk. It'll be enabled in Firefox 16 via bug 768265.