Revert of Revert of Enabling audio quality test on mac.

Revert of Revert of Enabling audio quality test on mac. (patchset #1 id:1 of https://codereview.chromium.org/613833002/)

Reason for revert:
Relanding: bots are now configured.

Original issue's description:
> Revert of Enabling audio quality test on mac. (patchset #1 id:1 of https://codereview.chromium.org/599103006/)
>
> Reason for revert:
> There is one stubborn bot that is unreachable from VNC; reverting until we can sort that out.
>
> Original issue's description:
> > Enabling audio quality test on mac.
> >
> > Note: will land on Monday; need to watch bots so that they execute the
> > test right.
> >
> > TBR=vrk@chromium.org
> > BUG=418034
> >
> > Committed: https://crrev.com/c4e4aaaf43c0da2a01c0f32be737dcbbd5f13e92
> > Cr-Commit-Position: refs/heads/master@{#297166}
>
> TBR=vrk@chromium.org
> NOTREECHECKS=true
> NOTRY=true
> BUG=418034
>
> Committed: https://crrev.com/18efcd361beccd5eca81b1a046c30fde72a88953
> Cr-Commit-Position: refs/heads/master@{#297257}

TBR=vrk@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=418034
Committed: https://crrev.com/5e4ae20f69a58256afcd5c146978446dfcc9b3fd
Cr-Commit-Position: refs/heads/master@{#297374}

[phoglund_chromium, 2014-09-30 07:08:17]

Created Revert of Revert of Enabling audio quality test on mac.

[commit-bot: I haz the power, 2014-09-30 07:08:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/612333002/1

[commit-bot: I haz the power, 2014-09-30 07:09:17]

Committed patchset #1 (id:1) as 7cb84e8c8f4809a2530800aa335c2bcae8ac872c

[commit-bot: I haz the power, 2014-09-30 07:11:58]

Patchset 1 (id:??) landed as
https://crrev.com/5e4ae20f69a58256afcd5c146978446dfcc9b3fd
Cr-Commit-Position: refs/heads/master@{#297374}