Roll src/third_party/skia 478d7d46f8d7..507158f88d4d (1 commits) (#7949)

https://skia.googlesource.com/skia.git/%2Blog/478d7d46f8d7..507158f88d4d

git log 478d7d46f8d7e14fa940fd7318f38e6cbc8bc19f..507158f88d4dd90d09588ea8c870b76defdfa91a --date=short --no-merges --format=%ad %ae %s
2019-02-25 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader b47c816ad7e6..e2d8b1286ce3 (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 (scroggo@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': '478d7d46f8d7e14fa940fd7318f38e6cbc8bc19f',
+  'skia_revision': '507158f88d4dd90d09588ea8c870b76defdfa91a',
 
   # 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: bb02dc4920cacedb57bb14197d80e96a
+Signature: 1fef5f1f89a091250bec208646570e2e
 
 UNUSED LICENSES: