Revert "Audio processing: Feed each processing step its choice of int or float data"

This reverts r6138.

tbr=kwiberg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/13509004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6142 4adac7df-926f-26a2-2b94-8c16560cd09d