Support shelf 0.7.0.

lib/src/runner/browser/iframe_test.dart

Index: lib/src/runner/browser/iframe_test.dart
diff --git a/lib/src/runner/browser/iframe_test.dart b/lib/src/runner/browser/iframe_test.dart
index e7e87da07737a7953e451b6895a0044c1f7f9ffc..07e4bfd20c1eddd0240ca30e6bae04d30058202f 100644
--- a/lib/src/runner/browser/iframe_test.dart
+++ b/lib/src/runner/browser/iframe_test.dart
@@ -2,6 +2,8 @@
 // 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';
@@ -12,7 +14,6 @@ import '../../backend/suite.dart';
 import '../../backend/test.dart';
 import '../../backend/test_platform.dart';
 import '../../utils.dart';
-import '../../util/multi_channel.dart';
 import '../../util/remote_exception.dart';
 import '../../util/stack_trace_mapper.dart';