Create minimized standalone test case for OSX audio hangs.

Create minimized standalone test case for OSX audio hangs.

NOT FOR SUBMISSION.

Repeatedly configures and starts two streams, waits for the first
callback on each stream, and then closes and destroys the streams.

To reproduce the bug, manually suspend (close the lid) and resume
(open the lid) the device until the beeping noise stops.  At this
point you should see the loop hung while waiting for the first
callback; e.g.,

   AudioOutputStream(0x00000001) created.
   AudioOutputStream(0x00000002) created.
     AudioOutputStream(0x00000001) started.
     AudioOutputStream(0x00000002) started.
   [ ... hangs ... ]

Usually only a few suspend and resume cycles are necessary to
reproduce the issue.

BUG=160920
TEST=compile, run, sleep, wake, sleep, ..., wake, hang!