While bringing up the new Flutter API integration tests, the C++ generator failed the AllDataTypes round-trip. From initial debugging it looks like the initial Dart->C++ call works, but the completion handler for the call back into Dart is never reached. That suggests it's likely an exception on the Dart side, so perhaps there's something wrong with the serialization in that direction.

For now I'm skipping the test for that generator to get the tests landed; the skip in integration_tests.dart that references this issue should be removed, and the failure fixed.