Roll Skia from 6b6015ff79b0 to ab4d4ae9e267 (1 revision) (flutter#32555)

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': '6b6015ff79b09f3b0ddcdf26574ce91f2d817717',
+  'skia_revision': 'ab4d4ae9e2679ce94a443cdd1eb8eff00b8a1256',
 
   # WARNING: DO NOT EDIT canvaskit_cipd_instance MANUALLY
   # See `lib/web_ui/README.md` for how to roll CanvasKit to a new version.