Roll WebRTC from 504198a50ef1 to 178937de8eba (1 revision)

https://webrtc.googlesource.com/src.git/+log/504198a50ef1..178937de8eba

2022-09-02 asapersson@webrtc.org api/video_codecs: Add scalability mode helper functions.

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 file a bug in WebRTC: https://bugs.chromium.org/p/webrtc/issues/entry
To file a bug in Chromium: https://bugs.chromium.org/p/chromium/issues/entry

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/main/autoroll/README.md

Bug: None
Tbr: webrtc-chromium-sheriffs-robots@google.com
Change-Id: Iba7b46dcf4072bc4f1e11cbdbe64db4be9efed7d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3871519
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Bot-Commit: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1042613}