Remove const for plain data types in common_audio/

BUG=1644
R=tina.legrand@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1464005

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4019 4adac7df-926f-26a2-2b94-8c16560cd09d
6 files changed