Roll src/third_party/webrtc d059dfbc06e0..dff792591fb9 (1 commits)

https://webrtc.googlesource.com/src.git/+log/d059dfbc06e0..dff792591fb9

git log d059dfbc06e0..dff792591fb9 --date=short --first-parent --format='%ad %ae %s'
2020-04-16 eshr@google.com Remove VideoStreamEncoderObserver::AdaptationReason::kNone

Created with:
  gclient setdep -r src/third_party/webrtc@dff792591fb9

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: If9d12e4cafb9b3dce7f702be8b04ab66f335c947
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2152868Reviewed-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@{#759712}

DEPS

@@ -1447,7 +1447,7 @@ deps = {
   },
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + 'd059dfbc06e06402a420ef4abec9b319e834e754',
+    Var('webrtc_git') + '/src.git' + '@' + 'dff792591fb90e6539f2638bc10f98c1946847f9',
 
   'src/third_party/libgifcodec':
      Var('skia_git') + '/libgifcodec' + '@'+  Var('libgifcodec_revision'),