Roll src/third_party/webrtc 6c13fd907145..b7dc45f8e811 (2 commits)

https://webrtc.googlesource.com/src.git/+log/6c13fd907145..b7dc45f8e811

git log 6c13fd907145..b7dc45f8e811 --date=short --first-parent --format='%ad %ae %s'
2020-01-21 mbonadei@webrtc.org Update check_package_boundaries.
2020-01-21 mbonadei@webrtc.org Remove android_junit_tests from the main BUILD.gn file.

Created with:
  gclient setdep -r src/third_party/webrtc@b7dc45f8e811

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: I286f6c7631e3e436d7188e2a1e40e8f332952b23
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2012232Reviewed-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@{#733591}

DEPS

@@ -1501,7 +1501,7 @@ deps = {
     Var('chromium_git') + '/external/github.com/gpuweb/cts.git' + '@' + 'ec18cc3262922e7dcdbe70243c6f40606f979144',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + '6c13fd9071453b435b46b04e52794c8172988a66',
+    Var('webrtc_git') + '/src.git' + '@' + 'b7dc45f8e8119d367b7513045db7cce68861709f',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),