Roll WebRTC from a4dfe24d7696 to f84ab8e2ddfa (2 revisions)

https://webrtc.googlesource.com/src.git/+log/a4dfe24d7696..f84ab8e2ddfa

2020-06-03 steveanton@webrtc.org Add publicly visible mock for PeerConnectionFactoryInterface
2020-06-03 steveanton@webrtc.org Mark mock_peerconnectioninterface.h as publicly visible

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: I94ea6e02ee2b713a8f5f4dc0c56a75e3c4bce487
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2229351Reviewed-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@{#774836}

DEPS

@@ -1452,7 +1452,7 @@ deps = {
   },
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + 'a4dfe24d7696145051c6929f778a100e6516d39c',
+    Var('webrtc_git') + '/src.git' + '@' + 'f84ab8e2ddfaf097d8f7904c77c9c12388ce0c92',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),