Roll src/third_party/webrtc 4854b9f8047e..3c5f91b74871 (2 commits)

https://webrtc.googlesource.com/src.git/+log/4854b9f8047e..3c5f91b74871

git log 4854b9f8047e..3c5f91b74871 --date=short --no-merges --format='%ad %ae %s'
2019-09-23 chromium-webrtc-autoroll@webrtc-ci.iam.gserviceaccount.com Roll chromium_revision e74d6b59..82de2e61 (698711:698813)
2019-09-21 chromium-webrtc-autoroll@webrtc-ci.iam.gserviceaccount.com Roll chromium_revision 5cbf4ebd..e74d6b59 (698593:698711)

Created with:
  gclient setdep -r src/third_party/webrtc@3c5f91b74871

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/+/master/autoroll/README.md

TBR=webrtc-chromium-sheriffs-robots@google.com

Bug: chromium:None,chromium:None
Change-Id: Id8a59b70eca32bb37fbcecb8b72666e9bd2475b4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1819003Reviewed-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@{#698824}

DEPS

@@ -1425,7 +1425,7 @@ deps = {
     Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + '7c4e67ff117d6c640e6dd17989afe2fb7da7eecb',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + '4854b9f8047e2dad15ff0536ed0a6d6f22bdc79e',
+    Var('webrtc_git') + '/src.git' + '@' + '3c5f91b74871ba0c716ab9650e9779064aa864ff',
 
   'src/third_party/xdg-utils': {
       'url': Var('chromium_git') + '/chromium/deps/xdg-utils.git' + '@' + 'd80274d5869b17b8c9067a1022e4416ee7ed5e0d',