Centralized event streams

runtime/observatory/lib/src/repositories/flag.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file
 
 part of repositories;
 
 class Flag implements M.Flag {
   final String name;
   final String comment;
   final bool modified;
   final String valueAsString;
   Flag(this.name, this.comment, this.modified, this.valueAsString) {
     assert(name != null);
     assert(comment != null);
     assert(modified != null);
   }
 }
 
 class FlagsRepository implements M.FlagsRepository {
-  Future<Iterable<Flag>> list(M.VM vm) async{
-    if (vm is S.VM) {
-      List<Map> flags = ((await vm.getFlagList()) as S.ServiceMap)['flags'];
-      return flags.map(_toFlag);
-    }
-    return const [];
+  final S.VM vm;
+
+  FlagsRepository(this.vm);
+
+  Future<Iterable<Flag>> list() async{
+    List<Map> flags = ((await vm.getFlagList()) as S.ServiceMap)['flags'];
+    return flags.map(_toFlag);
   }
 
   static _toFlag(Map map){
     return new Flag(map['name'],
                     map['comment'],
                     map['modified'],
                     map['valueAsString']);
   }
 }