Basic tests for MediaStreamAudioSourceNode API.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".

PASS {audio:true} generated stream
PASS s.getAudioTracks().length is 1
PASS s.getVideoTracks().length is 0
PASS Source AudioNode has no inputs.
PASS Source AudioNode has one output.
PASS connect() exception thrown for illegal destination AudioNode.
PASS connect() exception thrown for illegal output index.
PASS connect() exception thrown for illegal input index.
PASS mediaStreamSource.connect(context.destination) succeeded.
PASS successfullyParsed is true

TEST COMPLETE