Roll Dart SDK from 2a80a8adf898 to 776fad25647a (1 revision) (#47505)

https://dart.googlesource.com/sdk.git/+log/2a80a8adf898..776fad25647a

2023-10-31 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com Version 3.3.0-81.0.dev

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/dart-sdk-flutter-engine
Please CC dart-vm-team@google.com,zra@google.com on the revert to ensure that a human
is aware of the problem.

To file a bug in Flutter Engine: https://github.com/flutter/flutter/issues/new/choose

To report a problem with the AutoRoller itself, please file a bug:
https://issues.skia.org/issues/new?component=1389291&template=1850622

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md
diff --git a/DEPS b/DEPS
index 6f715eb..8848102 100644
--- a/DEPS
+++ b/DEPS
@@ -57,7 +57,7 @@
   # Dart is: https://github.com/dart-lang/sdk/blob/main/DEPS
   # You can use //tools/dart/create_updated_flutter_deps.py to produce
   # updated revision list of existing dependencies.
-  'dart_revision': '2a80a8adf8984b63acc8c558525f2059d9ab9fda',
+  'dart_revision': '776fad25647a7dcaa8127cb9b5b59227420977fe',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py
diff --git a/ci/licenses_golden/licenses_dart b/ci/licenses_golden/licenses_dart
index e8d7637..1adc341 100644
--- a/ci/licenses_golden/licenses_dart
+++ b/ci/licenses_golden/licenses_dart
@@ -1,4 +1,4 @@
-Signature: 3398c7cf570ba3540ef82fd337c0990c
+Signature: c872fbabf77f22f1266b3d0e3f10cd2c
 
 ====================================================================================================
 LIBRARY: dart