Bug 1042672 - Avoid mixing in uninitialized buffers in AudioSegment::WriteTo.  r=jesup
Bug 1042672 - s/aSamples/aFrames/ in AudioOutputObserver::InsertFarEnd so it's consistent with the rest of the media code. r=jesup


In Gecko (and everywhere else, but sometimes not in the WebRTC code), a "frame"
or "sample-frames" is the set of all sample that will play at the same time on
all channels, whereas a "sample" is a single value on a specific channel.