Roll src/third_party/webrtc a6db9c8fe927..c310889ec791 (3 commits)

https://webrtc.googlesource.com/src.git/+log/a6db9c8fe927..c310889ec791

git log a6db9c8fe927..c310889ec791 --date=short --first-parent --format='%ad %ae %s'
2020-02-26 sprang@webrtc.org Revert "Reland "Refactors UlpFec and FlexFec to use a common interface.""
2020-02-26 hta@webrtc.org Remove deprecated AddContent function in session_description.h
2020-02-25 chromium-webrtc-autoroll@webrtc-ci.iam.gserviceaccount.com Roll chromium_revision e1d61e44..159524df (744256:744393)

Created with:
  gclient setdep -r src/third_party/webrtc@c310889ec791

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: chromium:1052323
Tbr: webrtc-chromium-sheriffs-robots@google.com
Change-Id: I1017db1fb95a2c00fb4eea555813c88fa61c8a62
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2073784Reviewed-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@{#744624}

DEPS

@@ -1443,7 +1443,7 @@ deps = {
     Var('chromium_git') + '/external/github.com/gpuweb/cts.git' + '@' + 'ec18cc3262922e7dcdbe70243c6f40606f979144',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + 'a6db9c8fe9276774e3939d577c9320ad00fddd83',
+    Var('webrtc_git') + '/src.git' + '@' + 'c310889ec79167896e1d7b4b401c397fe1f51032',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),