Make dart2js unittests async.

tests/compiler/dart2js/type_guard_unuser_test.dart

Index: tests/compiler/dart2js/type_guard_unuser_test.dart
diff --git a/tests/compiler/dart2js/type_guard_unuser_test.dart b/tests/compiler/dart2js/type_guard_unuser_test.dart
index 7df302be77169e14d62c27917f0f180784eebf3d..a6703b9e9824940631add1e38ab2a01baf5fc8b4 100644
--- a/tests/compiler/dart2js/type_guard_unuser_test.dart
+++ b/tests/compiler/dart2js/type_guard_unuser_test.dart
@@ -2,7 +2,9 @@
 // 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:expect/expect.dart";
+import 'dart:async';
+import 'package:expect/expect.dart';
+import 'package:async_helper/async_helper.dart';
 import 'compiler_helper.dart';
 
 const String TEST_ONE = r"""
@@ -41,28 +43,31 @@ foo(int a, int b) {
 """;
 
 main() {
-  String generated = compile(TEST_ONE, entry: 'foo');
-  RegExp regexp = new RegExp(getIntTypeCheck(anyIdentifier));
-  Iterator<Match> matches = regexp.allMatches(generated).iterator;
-  checkNumberOfMatches(matches, 0);
-  Expect.isTrue(
-      generated.contains(
-          new RegExp(r'return a === true \? [$A-Z]+\.foo\(2\) : b;')));
-
-  generated = compile(TEST_TWO, entry: 'foo');
-  regexp = new RegExp("foo\\(1\\)");
-  matches = regexp.allMatches(generated).iterator;
-  checkNumberOfMatches(matches, 1);
-
-  generated = compile(TEST_THREE, entry: 'foo');
-  regexp = new RegExp(getNumberTypeCheck('a'));
-  Expect.isTrue(regexp.hasMatch(generated));
-  regexp = new RegExp(getNumberTypeCheck('b'));
-  Expect.isTrue(regexp.hasMatch(generated));
-
-  generated = compile(TEST_THREE_WITH_BAILOUT, entry: 'foo');
-  regexp = new RegExp(getNumberTypeCheck('a'));
-  Expect.isTrue(regexp.hasMatch(generated));
-  regexp = new RegExp(getNumberTypeCheck('b'));
-  Expect.isTrue(regexp.hasMatch(generated));
+  asyncTest(() => Future.wait([
+    compile(TEST_ONE, entry: 'foo', check: (String generated) {
+      RegExp regexp = new RegExp(getIntTypeCheck(anyIdentifier));
+      Iterator<Match> matches = regexp.allMatches(generated).iterator;
+      checkNumberOfMatches(matches, 0);
+      Expect.isTrue(
+          generated.contains(
+              new RegExp(r'return a === true \? [$A-Z]+\.foo\(2\) : b;')));
+    }),
+    compile(TEST_TWO, entry: 'foo', check: (String generated) {
+      RegExp regexp = new RegExp("foo\\(1\\)");
+      Iterator<Match> matches = regexp.allMatches(generated).iterator;
+      checkNumberOfMatches(matches, 1);
+    }),
+    compile(TEST_THREE, entry: 'foo', check: (String generated) {
+      RegExp regexp = new RegExp(getNumberTypeCheck('a'));
+      Expect.isTrue(regexp.hasMatch(generated));
+      regexp = new RegExp(getNumberTypeCheck('b'));
+      Expect.isTrue(regexp.hasMatch(generated));
+    }),
+    compile(TEST_THREE_WITH_BAILOUT, entry: 'foo', check: (String generated) {
+      RegExp regexp = new RegExp(getNumberTypeCheck('a'));
+      Expect.isTrue(regexp.hasMatch(generated));
+      regexp = new RegExp(getNumberTypeCheck('b'));
+      Expect.isTrue(regexp.hasMatch(generated));
+    })
+  ]));
 }