Roll WebRTC from a48dd43fe185 to dffa944e0725 (2 revisions)

https://webrtc.googlesource.com/src.git/+log/a48dd43fe185..dffa944e0725

2020-06-09 tommi@webrtc.org Reland "Remove dead code from ModuleRtpRtcpImpl2"
2020-06-09 tommi@webrtc.org Deprecate a few unused methods in RtpRtcpInterface

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: I2668c89f08ba5c1e6c89d2721842dfb393e05f13
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2237205
Reviewed-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@{#776546}

DEPS

@@ -1452,7 +1452,7 @@ deps = {
   },
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + 'a48dd43fe185ed6a826b7ce3bfee0b2187329159',
+    Var('webrtc_git') + '/src.git' + '@' + 'dffa944e0725794c939810c55797a2a6cefa69d6',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),