Changed to new ring buffer in AECM.

Replaced the old ring buffer in AECM with the new one. Also removed the old one from ring_buffer.
Changes are bit exact according to audioproc_unittest fixed.

TEST=audioproc_unittest
Review URL: http://webrtc-codereview.appspot.com/331022

git-svn-id: http://webrtc.googlecode.com/svn/trunk@1327 4adac7df-926f-26a2-2b94-8c16560cd09d
4 files changed