Roll WebRTC from 9bd68dad4d40 to 81a9117fb7aa (7 revisions)

https://webrtc.googlesource.com/src.git/+log/9bd68dad4d40..81a9117fb7aa

2024-04-08 jansson@google.com Roll chromium_revision 5350dd24..d5c79b10 (1281218:1283550)
2024-04-06 lndmrk@webrtc.org Remove expired WebRTC-Audio-NetEqFecDelayAdaptation
2024-04-05 danilchap@webrtc.org Require webrtc::Environment to create AV1 Encoder
2024-04-05 eshr@google.com Report proper VP9 scalability mode with layer activation.
2024-04-05 perkj@webrtc.org Remove unused TransportPacketsFeedback.first_unacked_send_time and prior_in_flight
2024-04-05 danilchap@webrtc.org Require webrtc::Environment to create VP9 encoder
2024-04-05 danilchap@webrtc.org Require webrtc::Environment to create H264 Encoder

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,webrtc-infra@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://issues.skia.org/issues/new?component=1389291&template=1850622

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: Ib4dbf2cec1c1a1bf849e41139a2fc351b4f9c8cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5432550
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@{#1283801}