Roll src/third_party/skia 1b53191539fc..6f615d6ebf9c (2 commits) (#10162)

https://skia.googlesource.com/skia.git
/compare/1b53191539fc..6f615d6ebf9c

git log 1b53191539fca8c6878bbbc4d8c1042562ae25c5..6f615d6ebf9c3eb2caa64a5c992afcd5c3311e04 --date=short --no-merges --format=%ad %ae %s
2019-07-26 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 557e3853da56..fab397e5acde (5 commits)
2019-07-25 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).

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

@@ -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': '1b53191539fca8c6878bbbc4d8c1042562ae25c5',
+  'skia_revision': '6f615d6ebf9c3eb2caa64a5c992afcd5c3311e04',
 
   # 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: 35e82723e3d20013cf8885aecc69da8a
+Signature: da8ef5c2c7bbb41c85dc03a2ad998ffe
 
 UNUSED LICENSES: