Roll Dart SDK from e2f14603dbb4 to bf814cfe61b9 (1 revision) (flutter#19879)

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': 'e2f14603dbb4459a725eb25a726e8aa137cfc545',
+  'dart_revision': 'bf814cfe61b97cdf43d1ef447fbfe52df5711b2b',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py