Roll WebRTC from aac41bd6780a to 81d691852dc8 (2 revisions)

https://webrtc.googlesource.com/src.git/+log/aac41bd6780a..81d691852dc8

2020-09-23 asapersson@webrtc.org SsrcEndToEndTest: Configure bitrate via VideoEncoderConfig.
2020-09-23 alessiob@webrtc.org AGC2 saturation protector: extra margin added by level estimator

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/webrtc-chromium-autoroll
Please CC webrtc-chromium-sheriffs-robots@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

Bug: None
Tbr: webrtc-chromium-sheriffs-robots@google.com
Change-Id: I9983dea6a4a720e7c59e191d2f163737fef15f75
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2426288Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#809812}

DEPS

@@ -1486,7 +1486,7 @@ deps = {
   },
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + 'aac41bd6780a152f51dfae7813d94dcc6f1dad49',
+    Var('webrtc_git') + '/src.git' + '@' + '81d691852dc8653adccd4e067e4731e8384c34b8',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),