dmazzoni's fixes to ALSA

After this change, speech_synthesis will not require PulseAudio in order to function.

Change-Id: I051e8ed0f46bde1058dfc606f3e60cfbc41e7d41

BUG=chromium-os:11321
TEST=manual

Review URL: http://codereview.chromium.org/6299025
2 files changed