Roll src/third_party/skia 21df075..e6a2ad8 (1 commits) (#14552)

https://skia.googlesource.com/skia.git/+log/21df075cab00..e6a2ad81ab40

git log 21df075..e6a2ad8 --date=short --first-parent --format='%ad %ae %s'
2019-12-18 rmistry@google.com Build and push skia-release and skia-wasm-release docker images

Created with:
  gclient setdep -r src/third_party/skia@e6a2ad81ab40

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 borenet@google.com 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/+/master/autoroll/README.md

Bug: None
Tbr: borenet@google.com

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': '21df075cab00b771ffc495707bb59d14160df513',
+  'skia_revision': 'e6a2ad81ab407cf59f5038cc3ee1998925408c33',
 
   # 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: 88e12fb1550820c171482e916cabcb67
+Signature: aa3b6f112eed8dcf37e5c7517d1efdde
 
 UNUSED LICENSES: