Roll src/third_party/skia 454e5fb7457d..233fc0b03c02 (4 commits) (flutter#7794)

https://skia.googlesource.com/skia.git/%2Blog/454e5fb7457d..233fc0b03c02

git log 454e5fb7457dacc4c508187ed879ceb6c9d0302d..233fc0b03c0255c96880e8e4561ee0d7eb352836 --date=short --no-merges --format=%ad %ae %s
2019-02-11 [email protected] remove unused cruft
2019-02-11 [email protected] Roll recipe dependencies (trivial).
2019-02-12 [email protected] Roll third_party/externals/angle2 fe59f6b5ed2b..ad194995ed72 (8 commits)
2019-02-10 [email protected] SkWuffsCodec: zero dst buffer before decodeFrame

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 ([email protected]), 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': '454e5fb7457dacc4c508187ed879ceb6c9d0302d',
+  'skia_revision': '233fc0b03c0255c96880e8e4561ee0d7eb352836',
 
   # 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: 7f16312dcc1a7eabb2005abe872bbe29
+Signature: f610deca58b93710bfc33d3c50818c00
 
 UNUSED LICENSES: