This change adds a UMA log that will be written to when a non-zero delay
correction is done in the AEC. The number of elements moved (positive or
negative) will be logged to
"WebRTC.Audio.AecDelayAdjustmentAgnosticValue" or
"WebRTC.Audio.AecDelayAdjustmentSystemValue", depending on whether
delay-agnostic AEC is used or not, respectively.
BUG=webrtc:5903
Review-Url: https://codereview.webrtc.org/1991723002
Cr-Commit-Position: refs/heads/master@{#12795}