Roll WebRTC from 9e81182f8ea5 to 39a3f081c129 (2 revisions)

https://webrtc.googlesource.com/src.git/+log/9e81182f8ea5..39a3f081c129

2020-09-24 gustaf@webrtc.org Disable transparent mode when ERL is bounded
2020-09-24 chromium-webrtc-autoroll@webrtc-ci.iam.gserviceaccount.com Roll chromium_revision b70f108b..fb765f65 (810146:810252)

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/+doc/master/autoroll/README.md

Bug: None
Tbr: webrtc-chromium-sheriffs-robots@google.com
Change-Id: I9235502a8d1dcb4da7f7e3a0f5ed0d60c18ad869
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2430230Reviewed-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@{#810508}

DEPS

@@ -1486,7 +1486,7 @@ deps = {
   },
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + '9e81182f8ea5f17339aa10b307f8f875422b667f',
+    Var('webrtc_git') + '/src.git' + '@' + '39a3f081c1298e42b0ec2e30d5d8660ae27fc63f',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),