This removes the nullOk parameter from Focus.of, FocusTraversalOrder.of and FocusTraversalGroup.of, and creates maybeOf equivalents for each. The of methods now return non-nullable values, and the maybeOf equivalents return nullable values.

This removes the nullOk parameter from AnimatedList.of and SliverAnimatedList.of, and creates maybeOf equivalents for each. The of methods now return non-nullable values, and the maybeOf equivalents return nullable values.

This removes the nullOk parameter from Router.of, and createsRouter.maybeOf. Router.ofnow returns a non-nullable value, and the Router.maybeOf returns a nullable value.

This removes the nullOk parameter from Shortcuts.of, Actions.find and Actions.handler and created Shortcuts.maybeOf and Actions.maybeFind. Shortcuts.of and Actions.find now return non-nullable values, and the maybe versions return a nullable value. I didn't create a non-nullable version of Actions.handler, since it needs to be able to return null if an action is not enabled, but I did remove the nullOk parameter, effectively setting it to true permanently, since setting it to false doesn't make much sense if the function can still return null when the action is not enabled.

Enable web tool integration tests: expression evaluation, stepping, and basic hot restart

Enables build_test for Linux. Currently only flutter_gallery has platform directories for the desktop platforms, so this will run only that build, but this will provide an end-to-end build test for Linux.

Other example/test projects can be brought online for Linux in the future just by adding the linux/ directory to the project.

* [devicelab] work around occasional null values for devtools

* Update perf_tests.dart

This reverts commit d0cdfa41.

Currently we only have a test that measures if flutter drive can fail. Unfortunately it has been failing for multiple years based on the fact that the error is due to a missing Gradle config.

Add a smoke success test case, and update both tests to use the test API and the tester-device.

073263e39 Roll Skia from 5bbbb49f1da0 to 7737a5bd2510 (13 revisions) (flutter/engine#22140) (#69231)

Support --web-renderer options which would allow user to specify which rendering backend to use. (#68848)

[flutter_tools] conditionally invoke pub run test for drive scripts based on presence of dependency (#69246)

* [flutter_tools] conditionally invoke pub run test for drive scripts based on presence of dependency

* [flutter_tools] stage web integration tests

* Improve resampling of up and remove events.

This improves resampling of these events by searching
for them until the next approximate sample time.
Co-authored-by: David Reveman <reveman@google.com>