Removed unused mock methods in audio_processing

TESTED=trybots,modules_unittests
R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/8999005

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@5597 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed