Roll src/third_party/webrtc c310889ec791..9731a14ff8ec (4 commits)

https://webrtc.googlesource.com/src.git/+log/c310889ec791..9731a14ff8ec

git log c310889ec791..9731a14ff8ec --date=short --first-parent --format='%ad %ae %s'
2020-02-26 brandtr@webrtc.org Improve logging for UpdateActiveSimulcastLayers.
2020-02-26 mirtad@webrtc.org Report available instead of encoding bitrate to VideoEncoderSelector.
2020-02-26 phoglund@webrtc.org Whitespace change to kick bots.
2020-02-26 chromium-webrtc-autoroll@webrtc-ci.iam.gserviceaccount.com Roll chromium_revision 159524df..0bba1cec (744393:744590)

Created with:
  gclient setdep -r src/third_party/webrtc@9731a14ff8ec

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: I061653cdaa571acf086f694f20ccece83b954e19
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2075439Reviewed-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@{#744781}

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' + '@' + 'c310889ec79167896e1d7b4b401c397fe1f51032',
+    Var('webrtc_git') + '/src.git' + '@' + '9731a14ff8ec3e09cf58c033898251dc2c75628f',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),