Roll Skia from 21c2af2dca60 to 3d019ddabc78 (2 revisions)

https://skia.googlesource.com/skia.git/+log/21c2af2dca60..3d019ddabc78

2021-07-29 [email protected] Support serialization of child effects for Runtime Blenders.
2021-07-29 [email protected] draw vertices: implement blending the tri-color shader

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-flutter-autoroll
Please CC [email protected] on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

Author: skia-flutter-autoroll

DEPS

@@ -27,7 +27,7 @@ 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': '21c2af2dca607e377b98bfe40748e35fe7ba961e',
+  'skia_revision': '3d019ddabc783ff20fe362ee125d102e2558edb8',
 
   # 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: 20e97a19cb6d05350e01abb631d1be0f
+Signature: d7ac5037c3259946ab2ac0e863410969
 
 UNUSED LICENSES: