A frequent request from the last Flutter developer survey was for an easier method of testing light/dark mode changes. Currently, a user needs to manually change the theme settings or adjust phone settings to see the difference. Instead we should add a toggle from the CLI, and eventually devtools/Intellij/Vscode that allows developers to override the current setting.

Fixes #59495

Adds flutter.ext.brightnessOverride service protocol which either queries the current platform brightness, or overrides it to a new value. This accepts either Brightness.light or Brightness.dark as a value.

Adds a CLI toggle b which allows the setting to be toggled manually.

Requires an update to the MediaQuery, to conditionally use a debug override when not in release mode

Failing dev/integration_tests/ui/test_driver/keyboard_resize_test.dart
Also timing out on new_gallery_ios__transition_perf

This reverts commit c7a37c72.

* Add comments to flutter_driver for timeline class

Mostly about explanation for the json items from
timeline.dart and timeline_summary.dart.

* Revert "Revert "Add clipBehavior to widgets with clipRect (#55977)" (#58344)"

This reverts commit 1d395c5e.

* Add missed Overflow

Fixes #59608

The VmService getter can be null, handle that in the listViews method. NNBD when

Broke iOS devicelab tests.

This reverts commit 90fb2e80.

This reverts commit e0ed12c7.

Remove dependency on package:collection by moving mergeSort into foundation/collections.dart (#59521)

This removes a dependency from Flutter (package:collection) by copying the implementation of mergeSort into Flutter's foundation/collections.dart.

Also, removed a reference to UnmodifiableSetView from the shortcuts code by just returning a copy instead.

After Dart VM change we are now required to use loadLibrary on an import whenever it is imported as deferred.

See: https://dart-review.googlesource.com/c/sdk/+/149613

Updates the tooling to use the GTK embedding, rather than the GLFW embedding:
- Adds new requirements to `doctor`
- Updates the app and plugin templates to make GTK-based runners and plugins
- Stops downloading and installing the GLFW artifacts

Final part of #54860, other than cleanup.

This command was previously used by the re-entrant build scripts in xcode_backend.sh and build.gradle. These have since been refactored to use flutter assemble.

Deprecation the command in preparation for removal in a future release of flutter. The only current use is a test on HHH

This will need to be moved, so we can skip for now to avoid issues around double uploading or changing the token config. The tool coverage is fairly steady and we're not losing any historical data.

[flutter_tools] ensure generated entrypoint matches test and web entrypoint language version (#59291)

Ensure that the language version of the test/web generated entrypoint matches the language version of the test file to run, or the overall package language version if no annotation is provided.

* Word substitutions

* ++