Roll WebRTC from 0f0bcb39f3fc to bc7e5ac1c908 (3 revisions)

https://webrtc.googlesource.com/src.git/+log/0f0bcb39f3fc..bc7e5ac1c908

2020-12-07 chromium-webrtc-autoroll@webrtc-ci.iam.gserviceaccount.com Roll chromium_revision 29886952..c24aab83 (834077:834189)
2020-12-07 sprang@webrtc.org Update how FEC handles protection parameters for key vs delta frames.
2020-12-07 alessiob@webrtc.org AGC2: Fix GetAvailableCpuFeatures()

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: I9480c297858830dbd5b0d24bb525513e2fee77e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2576014Reviewed-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@{#834335}

DEPS

@@ -1540,7 +1540,7 @@ deps = {
     Var('chromium_git') + '/external/github.com/gpuweb/cts.git' + '@' + '3c2fe3888658d82b47ca831d59a2e07579619c2d',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + '0f0bcb39f3fcb2b6185f146dfc4f4357276e40d4',
+    Var('webrtc_git') + '/src.git' + '@' + 'bc7e5ac1c9084e7c745b56fd199b8fd55e92c391',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),