Roll WebRTC from 111de34102c7 to 55c178693cdc (1 revision)

https://webrtc.googlesource.com/src.git/+log/111de34102c7..55c178693cdc

2020-09-28 eshr@google.com Add support for NV12 frame generation for tests

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: Ie04a2193ac57197b157072f2b66884227e6ca16b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2435257Reviewed-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@{#811207}

DEPS

@@ -1486,7 +1486,7 @@ deps = {
   },
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + '111de34102c7ab137a512796356c3683e54f636e',
+    Var('webrtc_git') + '/src.git' + '@' + '55c178693cdce4e4719181a12795506ea5500846',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),