Reland "Make VoiceEngine choose ACM2 by default""

This cl was originally committed as r5923, but was reverted in r5926
due to a blocking bug (issue 3143). The blocking bug was resolved in
r5936.

BUG=2996
TBR=henrika@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/12279004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@5950 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed