Roll src/third_party/webrtc 52c3688f08ac..73387823a715 (1 commits)

https://webrtc.googlesource.com/src.git/+log/52c3688f08ac..73387823a715

git log 52c3688f08ac..73387823a715 --date=short --first-parent --format='%ad %ae %s'
2020-01-20 srte@webrtc.org Cleanup: Removes MessageQueue header and alias

Created with:
  gclient setdep -r src/third_party/webrtc@73387823a715

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: I62b60aa0e28365f56d3cf2647c6643be52054f9b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2009827Reviewed-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@{#733324}

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' + '@' + '52c3688f08ac6466e5cb2f0dcccbd08759d8bfdd',
+    Var('webrtc_git') + '/src.git' + '@' + '73387823a7151c69bc914324ad5b724c97074677',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),