pkg/test: cleanup imports

lib/src/runner/runner_test.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.
 
 import 'package:stream_channel/stream_channel.dart';
 
 import '../backend/group.dart';
 import '../backend/live_test.dart';
 import '../backend/live_test_controller.dart';
 import '../backend/metadata.dart';
 import '../backend/operating_system.dart';
 import '../backend/state.dart';
 import '../backend/suite.dart';
 import '../backend/test.dart';
 import '../backend/test_platform.dart';
+import '../util/remote_exception.dart';
 import '../utils.dart';
-import '../util/remote_exception.dart';
 
 typedef StackTrace _MapTrace(StackTrace trace);
 
 /// A test running remotely, controlled by a stream channel.
 class RunnerTest extends Test {
   final String name;
   final Metadata metadata;
 
   /// The channel used to communicate with the test's [IframeListener].
   final MultiChannel _channel;
@@ skipping 56 matching lines @@
     }, groups: groups);
     return controller.liveTest;
   }
 
   Test forPlatform(TestPlatform platform, {OperatingSystem os}) {
     if (!metadata.testOn.evaluate(platform, os: os)) return null;
     return new RunnerTest(
         name, metadata.forPlatform(platform, os: os), _channel, _mapTrace);
   }
 }