Current implementation of AEC metrics does not read nicely. It messes up between a noise-removed calculation and a raw calculation.
I tried to clean it up, in which, I stick to the raw calculation since the noise-removed version can show some problem when the noise is overestimated.
BUG=
Review URL: https://codereview.webrtc.org/1581183005
Cr-Commit-Position: refs/heads/master@{#12455}