Roll src/third_party/skia 161f47d..21a486d (2 commits) (#9619)

https://skia.googlesource.com/skia.git
/%2Blog/161f47dfbf6a..21a486d

git log 161f47d..21a486d --date=short --no-merges --format=%ad %ae %s
2019-06-30 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update SKP version
2019-06-30 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update Go deps

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 (jvanverth@google.com), and stop
the roller if necessary.

Author: skia-flutter-autoroll

DEPS

@@ -26,7 +26,7 @@ vars = {
   'skia_git': 'https://skia.googlesource.com',
   # OCMock is for testing only so there is no google clone
   'ocmock_git': 'https://github.com/erikdoe/ocmock.git',
-  'skia_revision': '161f47dfbf6ae5641263d8c95a421d2e82ae4a36',
+  'skia_revision': '21a486d04ae034a9f4dcdc874a59b41391174db8',
 
   # 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: 82543ea3413512c8de3129733cc47be4
+Signature: 8edc904126bf9ea0c9079e0c06944ffd
 
 UNUSED LICENSES: