reland 260073013: Added automatic mode to FakeInputAudioStream to generate automatic beeps

reland 260073013: Added automatic mode to FakeInputAudioStream to generate automatic beeps

Added automatic mode to FakeInputAudioStream to generate automatic beeps.

This patch is to allow writing audio only tests using the fake input stream, also it changes the name of the fake device from "Default" to "Fake Audio, which I hope it will make things less confusing.

Previously it broke the mac bots due to it somehow triggered crbug/288562, crbug/371271, which should have been fixed by https://codereview.chromium.org/274073002/

TBR=ananta@chromium.org, dalecurtis@chromium.org

NOTRY=true

BUG=358541
TEST=bots existing webrtc tests.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=272884

[no longer working on chromium, 2014-05-26 10:06:26]

The CQ bit was checked by xians@chromium.org

[commit-bot: I haz the power, 2014-05-26 10:07:06]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/xians@chromium.org/279223002/60001

[commit-bot: I haz the power, 2014-05-26 11:59:38]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  android_aosp on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_aosp/builds/7...)
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)

[no longer working on chromium, 2014-05-26 13:26:50]

The CQ bit was unchecked by xians@chromium.org

[no longer working on chromium, 2014-05-26 13:26:55]

The CQ bit was checked by xians@chromium.org

[commit-bot: I haz the power, 2014-05-26 13:27:20]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/xians@chromium.org/279223002/60001

[commit-bot: I haz the power, 2014-05-26 23:52:04]

Change committed as 272884