Roll Dart SDK from fcaedc6d9587 to 2cec6af2652f (1 revision) (#21257)

DEPS

@@ -34,7 +34,7 @@ vars = {
   # Dart is: https://github.com/dart-lang/sdk/blob/master/DEPS.
   # You can use //tools/dart/create_updated_flutter_deps.py to produce
   # updated revision list of existing dependencies.
-  'dart_revision': 'fcaedc6d9587c005161a90d64bd32fd858760d55',
+  'dart_revision': '2cec6af2652ff859979987f568d18193df48163e',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py

ci/licenses_golden/licenses_third_party

-Signature: 962e5633685d33a69b598d96ab4c063c
+Signature: 3efa8608e94837e1d3aef3cd39f58189
 
 UNUSED LICENSES: