Current implementation runs timers and microtask callbacks in the root
zone. That assumes that the top-level `scheduleMicrotask` or `Timer`
constructors have been used, which have so far wrapped the callback with
`runCallbackGuarded` before calling the zone implementation.
That means that doing `zone.scheduleMicrotask` directly would not ensure
that the microtask was run in the correct zone. If a `run` handler
throws, it wouldn't be caught.
This change makes the `realAsyncZone` do whatever the root zone would do
if its `ZoneDelegate` got called with the intended zone and arguments.
That should be consistent with the current behavior, and be compatible
with incoming bug-fixes to the platform `Zone` behavior.
Prepares Flutter for landing
https://dart-review.googlesource.com/c/sdk/+/406961
which is currently blocked (so this indirectly fixes
https://github.com/dart-lang/sdk/issues/59913).
There are no new tests, the goal is that all existing tests keep
running, and that they keep doing so when the Dart CL lands. Currently
that CL only breaks one test, the
`dev/automated_tests/test_smoke_test/fail_test_on_exception_after_test.dart`
test which threw the error-after-test in the root zone instead of the
test zone. This change fixes that.
9e829cbd92