Roll src/third_party/webrtc 8643b78750bb..e61d72b37c64 (6 commits)

https://webrtc.googlesource.com/src.git/+log/8643b78750bb..e61d72b37c64


git log 8643b78750bb..e61d72b37c64 --date=short --no-merges --format='%ad %ae %s'
2018-06-15 yinwa@webrtc.org Disables congestion window in pacer when CongestionWindowPushback is enabled.
2018-06-15 nisse@webrtc.org Delete an unneeded include of pathutils.h.
2018-06-15 ilnik@webrtc.org Remove wire-up for cancelled experement on VAAPI VP8 encoding
2018-06-15 danilchap@webrtc.org Replace rtc::Optional with absl::optional in modules/rtp_rtcp
2018-06-15 nisse@webrtc.org Delete unused methods on rtc::Pathname.
2018-06-15 magjed@webrtc.org Android: Add helper class for generating OpenGL shaders


Created with:
  gclient setdep -r src/third_party/webrtc@e61d72b37c64

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

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=master.tryserver.chromium.linux:linux_chromium_archive_rel_ng;master.tryserver.chromium.mac:mac_chromium_archive_rel_ng

// Everything green except for purple bot (unrelated failure).
NOTRY=True

BUG=chromium:None,chromium:794608
TBR=webrtc-chromium-sheriffs-robots@google.com

Change-Id: Ia01ef0d0f498f78587fc27878cf7da12596641ea
Reviewed-on: https://chromium-review.googlesource.com/1102402Reviewed-by: Henrik Boström <hbos@chromium.org>
Reviewed-by: webrtc-chromium-autoroll <webrtc-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Commit-Queue: Henrik Boström <hbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567658}

DEPS

@@ -1010,7 +1010,7 @@ deps = {
     Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + '5e83981c2c44f24109b96b555d6865d481e0c609',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + '8643b78750bbd2a59482b9f36bccec91d2ed9238',
+    Var('webrtc_git') + '/src.git' + '@' + 'e61d72b37c64d970851976a490dc9d65061e1568',
 
   'src/third_party/xdg-utils': {
       'url': Var('chromium_git') + '/chromium/deps/xdg-utils.git' + '@' + 'd80274d5869b17b8c9067a1022e4416ee7ed5e0d',