Roll Dart SDK from 87df1bbcea5e to 3b9af2825d47 (2 revisions) (#44308)

https://dart.googlesource.com/sdk.git/+log/87df1bbcea5e..3b9af2825d47

2023-08-03 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com Version 3.2.0-30.0.dev
2023-08-02 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com Version 3.2.0-29.0.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 dart-vm-team@google.com,jacksongardner@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

DEPS

@@ -53,7 +53,7 @@ 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': '87df1bbcea5edc2c5b19839b81d717a17f33c190',
+  'dart_revision': '3b9af2825d47613a1c5b40a9617ad0506dd39f52',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py
@@ -473,7 +473,7 @@ deps = {
    Var('dart_git') + '/term_glyph.git@423700a3c019dc67f93d2bd6578016a1402506f7',
 
   'src/third_party/dart/third_party/pkg/test':
-   Var('dart_git') + '/test.git@7f81deeac294a1120917aeaa35d5b670146c4529',
+   Var('dart_git') + '/test.git@92eb0f7c3df8f3f089eb3962b46d55b00cf0e51c',
 
   'src/third_party/dart/third_party/pkg/test_reflective_loader':
    Var('dart_git') + '/test_reflective_loader.git@0bfaad91ed308ce9da11b48395c8210d7542c16b',