Moved the actual calculations to aec_core to avoid passing up low level members.

TEST=audioproc_unittest, trybots
BUG=None

Review URL: https://webrtc-codereview.appspot.com/1103011

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3521 4adac7df-926f-26a2-2b94-8c16560cd09d
3 files changed