Revert of Tighten up webrtc audio tests.

Revert of Tighten up webrtc audio tests. (https://codereview.chromium.org/216523003/)

Reason for revert:
This might have resulted in some flaky tests.  This failure happened two builds after the patch landed.

http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%282%29/builds/10598

See bug for more details.

BUG=358759
Original issue's description:
> Tighten up webrtc audio tests.
> 
> See http://goo.gl/LDae10. I'm trying to improve this algorithm. We used to
> check that some value was high enough and that the average was in the right
> ballpark. The new algorithm will count falling edges in the peaks instead,
> as a means to detect the peaks in the audio signal. The algorithm reliably
> yields one peak per second of sampled audio, which is correct because the
> audio signal beeps at 1 Hz. To get some margin, I'm sampling four seconds
> and checking that I get at least two peaks, which should be a rock solid 
> assumption even on slow machines.
> 
> BUG=357287, 357626
> R=perkj@chromium.org
> NOTRY=True
> (passed all trybots, just got stuck on a broken win trybot)
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=260878

TBR=perkj@chromium.org,phoglund@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=357287, 357626
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=260913

[rlarocque, 2014-04-01 19:05:44]

Created Revert of Tighten up webrtc audio tests.

[commit-bot: I haz the power, 2014-04-01 19:05:45]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rlarocque@chromium.org/220403006/1

[commit-bot: I haz the power, 2014-04-01 19:07:09]

Change committed as 260913

[phoglund_chromium, 2014-04-02 08:31:40]

On 2014/04/01 19:07:09, I haz the power (commit-bot) wrote:
> Change committed as 260913

This revert looks incorrect to me. You are referring to build 10598, but my
patch landed in 10599 on the same builder. Indeed, the flake you are seeing is
with the old code and is precisely what I tried to fix.