[Sealed class] Web debugging support

[itsjustkevin]

No description provided.

[nshahan]

@annagrin We need to investigate if this new language feature requires any special handling on the debugger side.

[a-siva]

On the VM side we implemented the ability to display this attribute for a class here
https://dart-review.googlesource.com/c/sdk/+/285360
The VM service API was modified for this and I presume the dwds would have to be changed to provide the same information.

[itsjustkevin]

Friendly ping.

[vsmenon]

@annagrin - anything we need to land here?

[annagrin]

I don't think so - we don't currently support any of the class attributes for web (we lack symbols). The vm_service update won't break dwds (tested the debugger with it).

@elliette do you know if class attributes are used or shown anywhere in DevTools for web or other platforms?

[elliette]

None of these class attributes are being used in DevTools or in DAP currently. This can be follow up for after Dart 3.0.0.

[itsjustkevin]

Moved to the Dart 3 cleanup milestone. Thank you @elliette and @annagrin!

[leafpetersen]

Anything to do here, or should we close this out?

[nshahan]

At this time there is nothing related to class modifiers shown in the debug tools. I'm closing and we can create a new issue if/when the UI makes use of that information.