Microphone test using alsa instead of pulsaaudio command.

BUG=chromium-os:12195
TEST=run_remote_tests.sh on both kaen-dvt and x86-alex

Review URL: http://codereview.chromium.org/6853017

Change-Id: I2dad6ff01ba91dcd13c2166c4cbcf997e48437cc
1 file changed