added HotRestartRequest to _deserializeMessage

[jyameo]

Fixes https://buganizer.corp.google.com/issues/484292194

[auto-submit]

autosubmit label was removed for dart-lang/webdev/2779, because - The status or check suite unit_test; linux; Dart main; PKG: webdev; Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &, `d... has failed. Please fix the issues identified (or deflake) before re-applying this label.

• The status or check suite unit_test; linux; Dart dev; PKG: webdev; Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &, `da... has failed. Please fix the issues identified (or deflake) before re-applying this label.

[nshahan]

LGTM but I have two questions:

1. Is this a type that needs the custom wire format that is backwards compatible with the built_value version used in the debug extension?
2. Can you think of any reasonable test we could add so we don't accidentally delete it in the future?

[jyameo]

1. Is this a type that needs the custom wire format that is backwards compatible with the built_value version used in the debug extension?

No, this type doesn’t require the custom wire format used for built_value compatibility (list based) in the debug extension. It uses standard JSON serialization (map based). I’ve refactored this by introducing _deserializeMessage and _serializeMessage to replace the previous serializers.serialize calls. I also added some comments to indicate which data types are list-based vs map-based.

2. Can you think of any reasonable test we could add so we don't accidentally delete it in the future?

Since this RPC request originates from the injected client, it requires E2E integration between Flutter tools and DWDS. I have already added some E2E tests for hot reload and hot restart over WebSockets in the Flutter repo that should catch regressions such as these.

CC @nshahan

[natebosch]

Do we expect the CI failures are existing problems or do they look related to this change?