Roll src/third_party/webrtc de365955dc6a..159b417c9827 (2 commits)

https://webrtc.googlesource.com/src.git/+log/de365955dc6a..159b417c9827

git log de365955dc6a..159b417c9827 --date=short --no-merges --format='%ad %ae %s'
2019-10-31 jakobi@webrtc.org Keep the video send stream alive if the encoder drop frames.
2019-10-31 mbonadei@webrtc.org Add RTC_EXPORT_TEMPLATE_{DECLARE,DEFINE} macros.

Created with:
  gclient setdep -r src/third_party/webrtc@159b417c9827

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: I03861a202b35cf07aaf185a7e940a24a78f1562c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1893177Reviewed-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@{#711248}

DEPS

@@ -1507,7 +1507,7 @@ deps = {
     Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + 'dd55f3ca8f2ea716ca917a4aaf36f0729fe902b1',
 
   'src/third_party/webrtc':
-    Var('webrtc_git') + '/src.git' + '@' + 'de365955dc6a17cc4ce520da3e8956bb2b322ce1',
+    Var('webrtc_git') + '/src.git' + '@' + '159b417c98270f3c134c32d3d5fe763e2221ff8c',
 
   # Wuffs' canonical repository is at github.com/google/wuffs, but we use
   # Skia's mirror of Wuffs, the same as in upstream Skia's DEPS file.