Roll Dart SDK from f452a6585cbd to 280a0c3efb21 (1 revision) (flutter#28910)

Author: skia-flutter-autoroll

DEPS

@@ -39,7 +39,7 @@ 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': 'f452a6585cbdc7804f07cdbf834bf8b7cef01faf',
+  'dart_revision': '280a0c3efb21592cbf9cab86f28f755078da27d2',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py
@@ -348,7 +348,7 @@ deps = {
    Var('dart_git') + '/external/github.com/google/webkit_inspection_protocol.dart.git' + '@' + Var('dart_webkit_inspection_protocol_rev'),
 
   'src/third_party/dart/third_party/pkg/yaml':
-   Var('dart_git') + '/yaml.git@2af44871f684c89e973a96e39026b8b88dda1987',
+   Var('dart_git') + '/yaml.git@ad0779d1baa25c6b10a192d080efc45de02b6a32',
 
   'src/third_party/dart/third_party/pkg/yaml_edit':
    Var('dart_git') + '/yaml_edit.git' + '@' + Var('dart_yaml_edit_rev'),

ci/licenses_golden/licenses_third_party

@@ -1,4 +1,4 @@
-Signature: a1d94d96e8963c4242a14585a024cb9d
+Signature: 30739706919cafd6de86de3790766902
 
 UNUSED LICENSES: