dart-lang/js-interop — pull request #69 by a14n (2013-04-11 18:52:05+00:00)
Title: replace Constructor with Serializable<FunctionProxy>

My first change was to make `Callback` implements `Serializable`.
This allows to simplify the definition of functions that need a callback in parameter. Thus, you can type your callback as `Serializable` and it will accept either `Callback` or `FunctionProxy` or `Serializable` (otherwise, you should have typed the callback as `dynamic`).

A `Constructor` being a function, I have removed it and have used `Serializable` instead.