Roll src/third_party/skia 15ecdf94fd36..f46c8268bf2b (3 commits) (#11800)

https://skia.googlesource.com/skia.git/+log/15ecdf94fd36..f46c8268bf2b

git log 15ecdf94fd36..f46c8268bf2b --date=short --no-merges --format='%ad %ae %s'
2019-08-30 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-08-30 fmalita@chromium.org [skottie] Discard unneeded static text animators
2019-08-30 dragonbear@google.com Override operator delete for GrCCPathCache::Key

Created with:
  gclient setdep -r src/third_party/skia@f46c8268bf2b

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 stani@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=stani@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': '15ecdf94fd36110285e25351dfa40acc158d60d3',
+  'skia_revision': 'f46c8268bf2b67c29ce6cd0a0f6e96ef8cddba0c',
 
   # 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: 253d1c938c8b6fc4ece856a10850b081
+Signature: 353a9ef4bae1352d0bb4cfbc46df9fd8
 
 UNUSED LICENSES: