Roll WebRTC from 5c978cb26289 to ff16f5f88e1a (6 revisions)

https://webrtc.googlesource.com/src.git/+log/5c978cb26289..ff16f5f88e1a

2023-03-07 hta@webrtc.org Add a new test binary to check if split-channel works
2023-03-07 mbonadei@webrtc.org Add docs about adding a new test binary.
2023-03-07 phancke@microsoft.com Rename header extension API methods
2023-03-07 ssilkin@webrtc.org Dump codec output to ivf/y4m
2023-03-06 ssilkin@webrtc.org Add rate adaptation tests
2023-03-06 danilchap@webrtc.org Unassign personal TODOs in modules/rtp_rtcp

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://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: chromium:1051821
Tbr: webrtc-chromium-sheriffs-robots@google.com
Change-Id: I3dc2c496774edc6a7e49e26f69e0a647838d182a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4315744
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@{#1113912}

DEPS

@@ -1884,7 +1884,7 @@ deps = {
     Var('chromium_git') + '/external/github.com/gpuweb/cts.git' + '@' + '6c8361e98f1daba65902f5e2fc1297893ac14b67',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + '5c978cb2628904afd588015dd4ca3522e1319ad0',
+    Var('webrtc_git') + '/src.git' + '@' + 'ff16f5f88e1af6b553abe2a847436ef0adce0900',
 
   # Wuffs' canonical repository is at github.com/google/wuffs, but we use
   # Skia's mirror of Wuffs, the same as in upstream Skia's DEPS file.