Reland "Refactor audio manager for Android to avoid heavy tasks at startup"

Reland "Refactor audio manager for Android to avoid heavy tasks at startup"

Original CL: https://codereview.chromium.org/110173003/.

Refactor audio manager for Android to avoid heavy tasks at startup.

Main goal of this CL is to avoid all demanding tasks (e.g. initiate audio routing, detect BT devices etc.) at Chrome startup.

All we do now is to populate the list of available devices. BT support has been removed but will be added in an upcoming CL.

NOTRY=True
TBR=bulach, tommi
BUG=324464
TEST=media_unittests --gtest-filter=AudioAndroid*

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=241247

[commit-bot: I haz the power, 2013-12-17 08:54:14]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/henrika@chromium.org/117073002/1

[commit-bot: I haz the power, 2013-12-17 09:46:11]

Commit queue rejected this change because the description was changed
between the time the change entered the commit queue and the time it
was ready to commit. You can safely check the commit box again.

[commit-bot: I haz the power, 2013-12-17 09:47:13]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/henrika@chromium.org/117073002/1

[commit-bot: I haz the power, 2013-12-17 09:47:24]

Change committed as 241247