Fix fuzzy arrow warnings since they will become errors before too long.

lib/src/runner/browser/browser_manager.dart

@@ -188,7 +188,7 @@ class BrowserManager {
     }));
 
     _environment = _loadBrowserEnvironment();
-    _channel.stream.listen(_onMessage, onDone: close);
+    _channel.stream.listen((message) => _onMessage(message), onDone: close);
   }
 
   /// Loads [_BrowserEnvironment].

lib/src/runner/configuration/load.dart

@@ -286,7 +286,8 @@ class _ConfigurationLoader {
 
     var paths = _getList("paths", (pathNode) {
       _validate(pathNode, "Paths must be strings.", (value) => value is String);
-      _validate(pathNode, "Paths must be relative.", p.url.isRelative);
+      _validate(pathNode, "Paths must be relative.",
+          (value) => p.url.isRelative(value));
 
       return _parseNode(pathNode, "path", p.fromUri);
     });

lib/src/runner/loader.dart

@@ -15,7 +15,6 @@ import '../backend/group.dart';
 import '../backend/invoker.dart';
 import '../backend/test_platform.dart';
 import '../util/io.dart';
-import '../utils.dart';
 import 'browser/platform.dart';
 import 'configuration.dart';
 import 'configuration/suite.dart';

pubspec.yaml

@@ -1,5 +1,5 @@
 name: test
-version: 0.12.27
+version: 0.12.27+1
 author: Dart Team <[email protected]>
 description: A library for writing dart unit tests.
 homepage: https://github.com/dart-lang/test

test/frontend/add_tear_down_test.dart

@@ -7,8 +7,6 @@ import 'dart:async';
 import 'package:async/async.dart';
 import 'package:test/test.dart';
 
-import 'package:test/src/backend/declarer.dart';
-
 import '../utils.dart';
 
 void main() {