fileSystem.chooseEntry from package:chrome/app.dart generates runtime error - dart

Question

Has anyone successfully used any fileSystem calls in package:chrome/app.dart? (This is the Chrome API package for Google Dart.)
Here's my code:
import 'package:chrome/app.dart';
void main() {
fileSystem.chooseEntry();
}
Here's my pubspec.yaml file:
name: ChooseEntry
description: A sample chrome packaged application
dependencies:
browser: any
chrome: any
meta: any
The other files were generated automatically by the Dart Editor and remain untouched by me.
The error I get from Dartium is:
Breaking on exception: 'package:chrome/src/common.dart': malformed type: line 72 pos 29: type 'js.Callback' is not loaded
When I compile to JS and run in Dartium or Chrome, I get this error:
Uncaught RuntimeError: Error: Cannot resolve 'Callback'.
So, my question is whether anyone has successfully used the chooseEntry API, or any API in fileSystem and, if so, what about what I did needs to be fixed. My guess is that I'm missing a package, but I can't identify what it might be.
I did add package "js" to pubspec.yaml, with no effect. I also tried making copies of all the packages, in case Dartium or Chrome didn't handle the symlinks correctly, and that didn't help either. (I doubt that that's the problem, as it found the code for fileSystem.chooseEntry just fine.)
I'm using:
Dart Editor version 1.0.0_r30798 (STABLE)
Dart SDK version 1.0.0.10_r30798

Answer 1

The chrome package appears not to be maintained anymore, consider using chrome_gen instead by replacing chrome with chrome_gen in pubspec.yaml and by editing the import statement like this:
import 'package:chrome_gen/chrome_app.dart';
main() {
fileSystem.chooseEntry();
}
The difference between these two packages is that wrappers are hand-written in chrome and autogenerated in chrome_gen from the json and idl files from Chrome.
Links:
Pub Package: chrome_gen
Mailing List: What is the difference between chrome and chrome_gen ?