Roll Dart SDK from 22d0f712b0a6 to 526b85706ed7 (1 revision) (flutter#24942)

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': '22d0f712b0a60a6d7f6c67af064248187b8dc950',
+  'dart_revision': '526b85706ed704331e22d8cbbe455ba64a4376e2',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py