Fix invalid bind usage during AudioManagerBase construction.

Fix invalid bind usage during AudioManagerBase construction.

Doh, the old way was not correct at all. We're using this 
before construction completes. /shame

Fixes a bunch of tsan error reports from the original CL: 
http://codereview.chromium.org/11175066/

BUG=none
TEST=unit tests still pass.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=163770

[Ami GONE FROM CHROMIUM, 2012-10-24 01:29:57]

LGTM

[commit-bot: I haz the power, 2012-10-24 01:31:13]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dalecurtis@chromium.org/11260002/1

[commit-bot: I haz the power, 2012-10-24 01:59:01]

Sorry for I got bad news for ya.
Compile failed with a clobber build on linux_rel.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2012-10-24 02:09:04]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dalecurtis@chromium.org/11260002/9

[commit-bot: I haz the power, 2012-10-24 04:23:50]

Change committed as 163770