Roll Dart SDK from c287db6 to 2553a84 (1 revision) (#23026)

Author: skia-flutter-autoroll

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': 'c287db6bf23201fc85eb27feb5a960ccef2a2917',
+  'dart_revision': '2553a84fe438d12bd5d36ab2ae059f593d9804ac',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py