Fix a couple bugs with OSX audio buffer size selection.

Fix a couple bugs with OSX audio buffer size selection.

1. Device changes may cause an already in process stream creation
to use the wrong buffer size => CHECK() failure.

2. Low latency stream Open() failure causes AudioOutputResampler
to fall back to a high latency buffer size, which will cause a
stream to be created with the wrong buffer size => CHECK() failure.

Fixing 2 has the added advantage of removing an extra useless hop
between stream Open() failure and switching to a fake audio output
device.

BUG=225249
TEST=audio works.


Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=192946

[Chris Rogers, 2013-04-01 21:13:51]

lgtm

[DaleCurtis, 2013-04-05 23:54:03]

scherkus: ping?

[scherkus (not reviewing), 2013-04-08 14:27:48]

lgtm

[commit-bot: I haz the power, 2013-04-08 16:54:32]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dalecurtis@chromium.org/13390010/1

[commit-bot: I haz the power, 2013-04-08 17:04:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dalecurtis@chromium.org/13390010/10002

[commit-bot: I haz the power, 2013-04-08 17:11:40]

Sorry for I got bad news for ya.
Compile failed with a clobber build on linux_chromeos_clang.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_chro...
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, 2013-04-08 18:53:30]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dalecurtis@chromium.org/13390010/7004

[commit-bot: I haz the power, 2013-04-08 23:28:38]

Change committed as 192946