Get rid of all the library tags.

lib/src/runner/engine.dart

 // Copyright (c) 2015, 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.
 
-library test.runner.engine;
-
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:async/async.dart' hide Result;
 import 'package:collection/collection.dart';
 import 'package:pool/pool.dart';
 
 import '../backend/group.dart';
 import '../backend/invoker.dart';
 import '../backend/live_test.dart';
@@ skipping 409 matching lines @@
     var futures = allLiveTests.map((liveTest) => liveTest.close()).toList();
 
     // Closing the load pool will close the test suites as soon as their tests
     // are done. For browser suites this is effectively immediate since their
     // tests shut down as soon as they're closed, but for VM suites we may need
     // to wait for tearDowns or tearDownAlls to run.
     futures.add(_loadPool.close());
     await Future.wait(futures, eagerError: true);
   }
 }