Roll src/third_party/skia adfc6e4..4dbb96d (6 commits) (#7970)

https://skia.googlesource.com/skia.git/%2Blog/adfc6e40df30..4dbb96dfaa04

git log adfc6e4..4dbb96d --date=short --no-merges --format=%ad %ae %s
2019-02-26 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader fe3d497..8adf1fc (2 commits)
2019-02-26 recipe-roller@chromium.org Roll recipe dependencies (trivial).
2019-02-26 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 024f271..fe3d497 (1 commits)
2019-02-26 brianosman@google.com Particles: remove non-stable random, add better enum reflection
2019-02-26 fmalita@chromium.org [skottie] Shape blending mode support
2019-02-26 bsalomon@google.com Remove legacy types/methods from SkDeferredDisplayList recorder.

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.

Author: skia-flutter-autoroll

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': 'adfc6e40df3081a8513ff71f2f434100b4d037b5',
+  'skia_revision': '4dbb96dfaa04868b4ed00ca90513097b2d987625',
 
   # 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

@@ -1,4 +1,4 @@
-Signature: 757465135c8291773be02574d403a257
+Signature: 724f50e9f5ec65dcf10c8d1cfcd729df
 
 UNUSED LICENSES: