Roll src/third_party/webrtc a7f77a7c05b5..50f60cb4b3a6 (4 commits)

https://webrtc.googlesource.com/src.git/+log/a7f77a7c05b5..50f60cb4b3a6


git log a7f77a7c05b5..50f60cb4b3a6 --date=short --no-merges --format='%ad %ae %s'
2018-11-07 yujo@chromium.org Rename software codec classes and move them into api/
2018-11-07 sprang@webrtc.org Remove non-default VideoEncoder::EncoderInfo() ctor
2018-11-07 sprang@webrtc.org Update MockVideoEncoder with correct methods.
2018-11-07 alessiob@webrtc.org Revert "Isolating APM API build target: making :api an actual target."


Created with:
  gclient setdep -r src/third_party/webrtc@50f60cb4b3a6

The AutoRoll server is located here: https://autoroll.skia.org/r/webrtc-chromium-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

CQ_INCLUDE_TRYBOTS=luci.chromium.try:linux_chromium_archive_rel_ng;luci.chromium.try:mac_chromium_archive_rel_ng
TBR=webrtc-chromium-sheriffs-robots@google.com

Change-Id: I2de05a4174f28cab6d6c5076cd250348776a8534
Reviewed-on: https://chromium-review.googlesource.com/c/1323229Reviewed-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@{#606089}

DEPS

@@ -1161,7 +1161,7 @@ deps = {
     Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + '0d55c887e92b645f6effe753528323ab2ffd94c2',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + 'a7f77a7c05b5d26520fd01a773ffb2c8b15b60ff',
+    Var('webrtc_git') + '/src.git' + '@' + '50f60cb4b3a6c293fede24ea5faa312a9414c628',
 
   'src/third_party/xdg-utils': {
       'url': Var('chromium_git') + '/chromium/deps/xdg-utils.git' + '@' + 'd80274d5869b17b8c9067a1022e4416ee7ed5e0d',