Roll Dart SDK from f596cf76c722 to 22d0f712b0a6 (1 revision) (flutter#24937)

Author: skia-flutter-autoroll

DEPS

@@ -35,7 +35,7 @@ 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': 'f596cf76c7225a54d63cd9e04d3676da9a99d463',
+  'dart_revision': '22d0f712b0a60a6d7f6c67af064248187b8dc950',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py