DevTools extension for package:jni

[HosseinYousefi]

This could be used for keeping track of the references, identifying leaks, etc.

See: https://medium.com/flutter/dart-flutter-devtools-extensions-c8bc1aaf8e5f

[dcharkes]

Did you mean the use of https://pub.dev/packages/leak_tracker in there?

I remember having a discussion with @polina-c before about the difference between Finalizable and Disposable (https://pub.dev/documentation/w_common/latest/disposable/Disposable-class.html) before. E.g. Disposables must have their dispose called by the programmer or it's a leak. Finalizables can have their release/free called eagerly. (I think the tricky part with finalizable's is probably not the GC or eager release, but cyclic reference between Java and Dart.)

Possibly we could hook stuff up to the leak tracker. 👍