This adds the histogram WebRTC.Audio.AudioMixer.NewHighestSourceCount
which logs the highest number of sources an AudioMixer has had. The
statistic is logged whenever the highest number of sources increases.
This allows us to differentiate the statistic to see how many times
the mixer has had a certain maximum number of sources.
Chromium CL:
https://chromium-review.googlesource.com/c/chromium/src/+/4414896
Bug: chromium:1430806
Change-Id: Iab92e201a0b667741cc8f3bbbed92fa989d7fcda
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/300860
Reviewed-by: Olga Sharonova <olka@webrtc.org>
Commit-Queue: Fredrik Hernqvist <fhernqvist@google.com>
Reviewed-by: Alessio Bazzica <alessiob@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39833}
79ea89ee74