Roll WebRTC from 58678a0eb7a3 to 449a78b1e20e (2 revisions)

https://webrtc.googlesource.com/src.git/+log/58678a0eb7a3..449a78b1e20e

2020-12-01 auorion@microsoft.com Prevent window enumeration deadlock and add unit tests.
2020-12-01 perkj@webrtc.org Add class InterArrivalDelta to goog_cc

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: chromium:1152841
Tbr: webrtc-chromium-sheriffs-robots@google.com
Change-Id: I4623c206190a22f417dcfd05632e23479bc87c24
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2566973Reviewed-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@{#832614}

DEPS

@@ -1551,7 +1551,7 @@ deps = {
   },
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + '58678a0eb7a35d2b7f75770d1d04fdd0684ab55c',
+    Var('webrtc_git') + '/src.git' + '@' + '449a78b1e20ea85b11f967cf3a184ee610ce21c3',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),