Roll src/third_party/webrtc ff9b8cccfc47..13188a24a490 (2 commits)

https://webrtc.googlesource.com/src.git/+log/ff9b8cccfc47..13188a24a490

git log ff9b8cccfc47..13188a24a490 --date=short --first-parent --format='%ad %ae %s'
2020-03-09 chromium-webrtc-autoroll@webrtc-ci.iam.gserviceaccount.com Roll chromium_revision 599bebd3..b57f55e2 (747722:748149)
2020-03-09 jianj@google.com VP9 test: change threshold to allow resizing for twice

Created with:
  gclient setdep -r src/third_party/webrtc@13188a24a490

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: I98b3ffd4a2f76be657fe676d37bd55a6d769d2e4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2094604Reviewed-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@{#748203}

DEPS

@@ -1454,7 +1454,7 @@ deps = {
     Var('chromium_git') + '/external/github.com/gpuweb/cts.git' + '@' + 'ec18cc3262922e7dcdbe70243c6f40606f979144',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + 'ff9b8cccfc47adc42d606a63a2cb78eac79be3ab',
+    Var('webrtc_git') + '/src.git' + '@' + '13188a24a490d51034839498451694cf0585810e',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),