Roll Dart SDK from 98ea0b4971dd to 44fa3b9e566c (1 revision) (flutter#21695)

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': '98ea0b4971dd2930c8fa19376ae3932574cfbc7f',
+  'dart_revision': '44fa3b9e566c3aa66c4a0dd9608c435b043190e9',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py