Revert 5184 "Small refactoring change in delay_estimator."
Revert 5184 "Small refactoring change in delay_estimator."

> Small refactoring change in delay_estimator.
> 
> This CL produce the bit exact output and is a preparing step for an upcoming robust validation scheme.
> 
> TESTED=trybots, module_unittest
> BUG=None
> R=aluebs@webrtc.org
> 
> Review URL: https://webrtc-codereview.appspot.com/4549004

TBR=bjornv@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/4589004

Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 82eb3a690e7fb4f34f266492a04ab7caec0d0fe0

sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc