Roll src/third_party/skia 1386b2d5579d..8b9b8f8c5846 (3 commits) (#8162)

https://skia.googlesource.com/skia.git/%2Blog/1386b2d5579d..8b9b8f8c5846

git log 1386b2d5579d45be7a81f8706ad1c407e1210dab..8b9b8f8c58467fef47b74250301d574ee31d5f79 --date=short --no-merges --format=%ad %ae %s
2019-03-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src 54744c955cd6..6299cd6e9d2d (421 commits)
2019-03-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader b6d4ce3158ee..868ed908f432 (1 commits)
2019-03-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 4ef71eb81f5d..b6d4ce3158ee (1 commits)

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-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 (benjaminwagner@google.com), and stop
the roller if necessary.

DEPS

@@ -23,7 +23,7 @@ vars = {
   'fuchsia_git': 'https://fuchsia.googlesource.com',
   'github_git': 'https://github.com',
   'skia_git': 'https://skia.googlesource.com',
-  'skia_revision': '1386b2d5579d45be7a81f8706ad1c407e1210dab',
+  'skia_revision': '8b9b8f8c58467fef47b74250301d574ee31d5f79',
 
   # 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: 2f6d3d116cd822ba2dfe40076649205b
+Signature: 4a847808a214cad2d193d34eccac95b7
 
 UNUSED LICENSES: