This CL is one step in a larger change of the DelayEstimator where we will open up for multiple near-end signals.
This particular CL separates the low level far-end parts without affecting the usage externally. This is a first step towards separating the far-end and near-end parts giving the user the control.
BUG=None
TEST=audioproc_unittests, trybots
Review URL: https://webrtc-codereview.appspot.com/1068005
git-svn-id: http://webrtc.googlecode.com/svn/trunk@3415 4adac7df-926f-26a2-2b94-8c16560cd09d