import 'dart:mirrors';
import 'lib.dart';
import 'lib2.dart' as lib2;

void main() {
  print(reflectClass(Foo).members[const Symbol('bar')]);
  print(reflectClass(lib2.Foo).members[const Symbol('bar')]);
}

lib.dart:

library lib;

class Foo {
  static String bar = '...';
}

lib2.dart:

library lib2;

class Foo {
  static String bar = '...';
}

Running:
dart2js -o test.dart.dart test.dart --output-type=dart --analyze-all -c

Produces (prettified):
import "dart:mirrors" as p;
class Foo{static String bar='...';}
class p_Foo{static String p_bar='...';}
void main(){
  print(p.reflectClass(Foo).members[const Symbol(r'bar')]);
  print(p.reflectClass(p_Foo).members[const Symbol(r'bar')]);
}

Where second print prints null after dart2dart.