Roll src/third_party/webrtc c4e80ad3bbc5..7bf7a427bfcc (1 commits)

https://webrtc.googlesource.com/src.git/+log/c4e80ad3bbc5..7bf7a427bfcc

git log c4e80ad3bbc5..7bf7a427bfcc --date=short --no-merges --format='%ad %ae %s'
2019-09-16 nisse@webrtc.org Delete flag VideoReceiveStream::Config::Rtp::remb

Created with:
  gclient setdep -r src/third_party/webrtc@7bf7a427bfcc

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: None
Change-Id: I2a95b1e245fe38777e8b66bb2c02a4c0dc7d0f59
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1805720Reviewed-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@{#696787}

DEPS

@@ -1425,7 +1425,7 @@ deps = {
     Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + 'abaae129d9a0c6e1e092067e0b105475df43352e',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + 'c4e80ad3bbc5f02f1e46798a1111d3ddba560b0c',
+    Var('webrtc_git') + '/src.git' + '@' + '7bf7a427bfcc9f398d90632aad54dc32372d8578',
 
   'src/third_party/xdg-utils': {
       'url': Var('chromium_git') + '/chromium/deps/xdg-utils.git' + '@' + 'd80274d5869b17b8c9067a1022e4416ee7ed5e0d',