Roll src/third_party/skia b7af275ebbf5..8a484d0203d9 (3 commits) (#7652)

https://skia.googlesource.com/skia.git/%2Blog/b7af275ebbf5..8a484d0203d9

git log b7af275ebbf55b6c79cf361bcf87612b328ea50a..8a484d0203d954a5ac4c7deb0f774dbe6a6fa9be --date=short --no-merges --format=%ad %ae %s
2019-01-31 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src 97fa6e4bdf7b..5d360ebe1581 (482 commits)
2019-01-31 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 77630f1e7d12..787f953343b0 (1 commits)
2019-01-31 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 fa7ca18f44ed..783809808ec0 (3 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 (borenet@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': 'b7af275ebbf55b6c79cf361bcf87612b328ea50a',
+  'skia_revision': '8a484d0203d954a5ac4c7deb0f774dbe6a6fa9be',
 
   # 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: 5b33ea5f6a7e1e09a65ad9184e872823
+Signature: ac5d42d5f02cbc67ee3e8e81d55c64c4
 
 UNUSED LICENSES: