Roll src/third_party/skia 20eafffd2d2f..b80d31f8cbe2 (4 commits) (#13226)

https://skia.googlesource.com/skia.git/+log/20eafffd2d2f..b80d31f8cbe2

git log 20eafffd2d2f..b80d31f8cbe2 --date=short --no-merges --format='%ad %ae %s'
2019-10-18 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 ed6e230ec65e..6dee176c8d7d (11 commits)
2019-10-18 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update Go deps
2019-10-18 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 6652f0b64287..a68a80a4dbf9 (1 commits)
2019-10-18 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src e27799abf3f0..7ca6de3adb8e (467 commits)

Created with:
  gclient setdep -r src/third_party/skia@b80d31f8cbe2

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-flutter-autoroll
Please CC csmartdalton@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=csmartdalton@google.com

DEPS

@@ -26,7 +26,7 @@ vars = {
   'skia_git': 'https://skia.googlesource.com',
   # OCMock is for testing only so there is no google clone
   'ocmock_git': 'https://github.com/erikdoe/ocmock.git',
-  'skia_revision': '20eafffd2d2fa3e966e05ba0ffd0a3256e9b9415',
+  'skia_revision': 'b80d31f8cbe28ec43db74a50f01bc695404ffa91',
 
   # When updating the Dart revision, ensure that all entries that are
   # dependencies of Dart are also updated to match the entries in the

ci/licenses_golden/licenses_skia

-Signature: 7f79d644d2fa9f5a6f51e35affa2b086
+Signature: a021f7cbae384bad66494e6292da5892
 
 UNUSED LICENSES: