Merge 171701

Merge 171701
> Delay delivery of audio input data.
> 
> The AudioQueue API may use a large internal buffer and repeatedly call us
> back to back once that internal buffer is filled.  When this happens the
> renderer client does not have enough time to read data back from the
> shared memory before the next write comes along.  If HandleInputBuffer()
> is called too frequently, Sleep() to simulate realtime input and ensure
> the shared memory doesn't get trampled.
> 
> BUG=157613
> TEST=Playback works on older style Mac units.
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=171681
> 
> Review URL: https://codereview.chromium.org/11482002

TBR=dalecurtis@google.com
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=172093