Make dart2js unittests async.

tests/compiler/dart2js/pretty_parameter_test.dart

Index: tests/compiler/dart2js/pretty_parameter_test.dart
diff --git a/tests/compiler/dart2js/pretty_parameter_test.dart b/tests/compiler/dart2js/pretty_parameter_test.dart
index 91f00fd935218c211d108e77fbd46923f6a2cfe7..723683b38122e7a07322c7be83af3b964a1a9f55 100644
--- a/tests/compiler/dart2js/pretty_parameter_test.dart
+++ b/tests/compiler/dart2js/pretty_parameter_test.dart
@@ -3,7 +3,9 @@
 // BSD-style license that can be found in the LICENSE file.
 // Test that parameters keep their names in the output.
 
-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 FOO = r"""
@@ -71,26 +73,34 @@ int foo(var start, bool test) {
 """;
 
 main() {
-  String generated = compile(FOO, entry: 'foo');
-  Expect.isTrue(generated.contains(r"function(a, b) {"));
+  asyncTest(() => Future.wait([
+    compile(FOO, entry: 'foo', check: (String generated) {
+      Expect.isTrue(generated.contains(r"function(a, b) {"));
+    }),
 
-  generated = compile(BAR, entry: 'bar');
-  Expect.isTrue(generated.contains(r"function($eval, $$eval) {"));
+    compile(BAR, entry: 'bar', check: (String generated) {
+      Expect.isTrue(generated.contains(r"function($eval, $$eval) {"));
+    }),
 
-  generated = compile(PARAMETER_AND_TEMP, entry: 'bar');
-  Expect.isTrue(generated.contains(r"print(t00)"));
-  // Check that the second 't0' got another name.
-  Expect.isTrue(generated.contains(r"print(t01)"));
+    compile(PARAMETER_AND_TEMP, entry: 'bar', check: (String generated) {
+      Expect.isTrue(generated.contains(r"print(t00)"));
+      // Check that the second 't0' got another name.
+      Expect.isTrue(generated.contains(r"print(t01)"));
+    }),
 
-  generated = compile(MULTIPLE_PHIS_ONE_LOCAL, entry: 'foo');
-  Expect.isTrue(generated.contains("var a;"));
-  // Check that there is only one var declaration.
-  checkNumberOfMatches(new RegExp("var").allMatches(generated).iterator, 1);
+    compile(MULTIPLE_PHIS_ONE_LOCAL, entry: 'foo', check: (String generated) {
+      Expect.isTrue(generated.contains("var a;"));
+      // Check that there is only one var declaration.
+      checkNumberOfMatches(new RegExp("var").allMatches(generated).iterator, 1);
+    }),
 
-  generated = compile(NO_LOCAL, entry: 'foo');
-  Expect.isFalse(generated.contains('var'));
+    compile(NO_LOCAL, entry: 'foo', check: (String generated) {
+      Expect.isFalse(generated.contains('var'));
+    }),
 
-  generated = compile(PARAMETER_INIT, entry: 'foo');
-  // Check that there is only one var declaration.
-  checkNumberOfMatches(new RegExp("var").allMatches(generated).iterator, 1);
+    compile(PARAMETER_INIT, entry: 'foo', check: (String generated) {
+      // Check that there is only one var declaration.
+      checkNumberOfMatches(new RegExp("var").allMatches(generated).iterator, 1);
+    }),
+  ]));
 }