Roll Dart SDK from 1e37edb to 2b6909b (1 revision) (#37516)

https://dart.googlesource.com/sdk.git/+log/1e37edb1f6c1..2b6909ba35e5

2022-11-11 [email protected] Version 2.19.0-390.0.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 [email protected],[email protected] 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

@@ -48,7 +48,7 @@ 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': '1e37edb1f6c1cd50fa38b16dbbbcfd4de8d26540',
+  'dart_revision': '2b6909ba35e59d2c7efd0ac2d0b9918f9263a039',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py

ci/licenses_golden/licenses_third_party

@@ -1,4 +1,4 @@
-Signature: e7170a284c3a1dbbb8570b5ba6771d34
+Signature: 3253fb53101f65b5cf30852bdef8b5fc
 
 UNUSED LICENSES: