Roll src/third_party/webrtc ddef8d1b6b07..9e380fd484db (6 commits)

https://webrtc.googlesource.com/src.git/+log/ddef8d1b6b07..9e380fd484db

git log ddef8d1b6b07..9e380fd484db --date=short --no-merges --format='%ad %ae %s'
2019-09-09 sprang@webrtc.org Improve performance of RtpPacketHistory
2019-09-09 ilnik@webrtc.org Reland "Refactor FEC code to use COW buffers"
2019-09-09 sprang@webrtc.org Remove usage of RtpRtcp::SetSSRC() in RtpRtcpImplTest
2019-09-09 andreidumitru@google.com Add option to enable retransmission for all temporal layers in the constructor for rtp_sender_video.
2019-09-09 eshr@google.com Add qualityLimitationResolutionChanges stat
2019-09-09 orphis@webrtc.org Connect the stable target rate to the video encoders

Created with:
  gclient setdep -r src/third_party/webrtc@9e380fd484db

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

TBR=webrtc-chromium-sheriffs-robots@google.com

Bug: None
Change-Id: I9af999abb9d9d2f1b7314fc027cc03e591ad786a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1793227Reviewed-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@{#694869}

DEPS

@@ -1414,7 +1414,7 @@ deps = {
     Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + 'abaae129d9a0c6e1e092067e0b105475df43352e',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + 'ddef8d1b6b073f5cf16092ba859159ae93a1c6d2',
+    Var('webrtc_git') + '/src.git' + '@' + '9e380fd484db09c37323b90a19c5ce7965927975',
 
   'src/third_party/xdg-utils': {
       'url': Var('chromium_git') + '/chromium/deps/xdg-utils.git' + '@' + 'd80274d5869b17b8c9067a1022e4416ee7ed5e0d',