Roll src/third_party/webrtc 9b289b2c2973..4b6df1777cba (1 commits)

https://webrtc.googlesource.com/src.git/+log/9b289b2c2973..4b6df1777cba

git log 9b289b2c2973..4b6df1777cba --date=short --first-parent --format='%ad %ae %s'
2020-01-10 thomasanderson@chromium.org Update Linux documentation links

Created with:
  gclient setdep -r src/third_party/webrtc@4b6df1777cba

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

Bug: None
Tbr: webrtc-chromium-sheriffs-robots@google.com
Change-Id: I6d041aea175da5de05ec33c24756cce67befcaa8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1995141Reviewed-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@{#730117}

DEPS

@@ -1498,7 +1498,7 @@ deps = {
     Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + '88d715c9115a5ce65c0bf660209dfeee9131ccd0',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + '9b289b2c2973a35d5da3929b6dabf1d26ca49cba',
+    Var('webrtc_git') + '/src.git' + '@' + '4b6df1777cbaa5cf66d65e551b41a43114fb8cd1',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),