Roll src/third_party/webrtc 37120ab59d1f..42748d8e22aa (3 commits)

https://webrtc.googlesource.com/src.git/+log/37120ab59d1f..42748d8e22aa

git log 37120ab59d1f..42748d8e22aa --date=short --first-parent --format='%ad %ae %s'
2020-05-14 danilchap@webrtc.org In rtc_base/ and api/ replace mock macros with unified MOCK_METHOD macro
2020-05-14 marinaciocea@webrtc.org Add GetMetadata() to TransformableVideoFrameInterface API.
2020-05-14 danilchap@webrtc.org In video/ replace mock macros with unified MOCK_METHOD macro

Created with:
  gclient setdep -r src/third_party/webrtc@42748d8e22aa

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: chromium:1069295
Tbr: webrtc-chromium-sheriffs-robots@google.com
Change-Id: I65ff4f414633216d520483d57e7a8c8c650f2423
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2202495Reviewed-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@{#769049}

DEPS

@@ -1453,7 +1453,7 @@ deps = {
   },
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + '37120ab59d1ffbc898aaaf09004c75ff92e3c26b',
+    Var('webrtc_git') + '/src.git' + '@' + '42748d8e22aa1abb4383c4829fbb3d7c7485dccd',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),