Roll Dart SDK from 5687f08b854d to afb0adeca5b6 (2 revisions)

https://dart.googlesource.com/sdk.git/+log/5687f08b854d..afb0adeca5b6

2023-04-15 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com Version 3.1.0-9.0.dev
2023-04-14 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com Version 3.1.0-8.0.dev

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/dart-sdk-flutter-engine
Please CC aam@google.com,dart-vm-team@google.com,jacksongardner@google.com,rmistry@google.com on the revert to ensure that a human
is aware of the problem.

To file a bug in Flutter Engine: https://github.com/flutter/flutter/issues/new/choose

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

Author: skia-flutter-autoroll

DEPS

@@ -47,7 +47,7 @@ vars = {
   # Dart is: https://github.com/dart-lang/sdk/blob/main/DEPS
   # You can use //tools/dart/create_updated_flutter_deps.py to produce
   # updated revision list of existing dependencies.
-  'dart_revision': '5687f08b854d820f05e64334139953bb50194690',
+  'dart_revision': 'afb0adeca5b61290db3cfac78a59816aba79af1e',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py
@@ -460,7 +460,7 @@ deps = {
    Var('dart_git') + '/test_reflective_loader.git@a85a930ad3736f93b96f6cc104d3576c1ae19e0e',
 
   'src/third_party/dart/third_party/pkg/tools':
-   Var('dart_git') + '/tools.git@58d914764eab030bf537c2c58089c8ba7b46a313',
+   Var('dart_git') + '/tools.git@2308c672e0d7446f5bfdba96594b41f26fa24a2e',
 
   'src/third_party/dart/third_party/pkg/typed_data':
    Var('dart_git') + '/typed_data.git@d85363d2efb333afce07ec409a529ec32986e1a2',