Roll WebRTC from 2157c5d256c2 to d7f750f7be4b (1 revision)

https://webrtc.googlesource.com/src.git/+log/2157c5d256c2..d7f750f7be4b

2020-12-18 chromium-webrtc-autoroll@webrtc-ci.iam.gserviceaccount.com Roll chromium_revision 31e5ea78..c48f2952 (838188:838429)

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: I5785e5445848065960533d8b2482ec6b2515a52b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2597319Reviewed-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@{#838448}

DEPS

@@ -1514,7 +1514,7 @@ deps = {
     Var('chromium_git') + '/external/github.com/gpuweb/cts.git' + '@' + '3c2fe3888658d82b47ca831d59a2e07579619c2d',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + '2157c5d256c2c32995def0a67a448dd1928edef5',
+    Var('webrtc_git') + '/src.git' + '@' + 'd7f750f7be4b2f61018d3cb55a995d09daa226e6',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),