Add DartWorkManager to manage Dart-specific results computation scheduling.

pkg/analyzer/test/generated/test_support.dart

 // Copyright (c) 2014, 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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.test_support;
 
 import 'dart:collection';
@@ skipping 576 matching lines @@
   }
   String get shortName {
     return _name;
   }
   Uri get uri {
     throw new UnsupportedOperationException();
   }
   UriKind get uriKind {
     throw new UnsupportedOperationException();
   }
+  @override
+  String toString() => '$_name';
   bool operator ==(Object other) {
     if (other is TestSource) {
       return other._name == _name;
     }
     return false;
   }
   bool exists() => exists2;
   void getContentsToReceiver(Source_ContentReceiver receiver) {
     throw new UnsupportedOperationException();
   }
@@ skipping 30 matching lines @@
     if (other is TestSource) {
       return other.uri == uri;
     }
     return false;
   }
 
   Uri resolveRelativeUri(Uri uri) {
     return this.uri.resolveUri(uri);
   }
 }