First pass at asynchronous input loading in dart2js.

tests/compiler/dart2js/simple_inferrer_final_field2_test.dart

Index: tests/compiler/dart2js/simple_inferrer_final_field2_test.dart
diff --git a/tests/compiler/dart2js/simple_inferrer_final_field2_test.dart b/tests/compiler/dart2js/simple_inferrer_final_field2_test.dart
index 75bf80373913bcd77e53668cae3ce5adb9b1d257..fa7b6f5dbce1ca67624ed92f9185459209cfc3e8 100644
--- a/tests/compiler/dart2js/simple_inferrer_final_field2_test.dart
+++ b/tests/compiler/dart2js/simple_inferrer_final_field2_test.dart
@@ -6,6 +6,7 @@
 // infering types for fields.
 
 import 'package:expect/expect.dart';
+import "package:async_helper/async_helper.dart";
 import 'compiler_helper.dart';
 import 'parser_helper.dart';
 
@@ -26,15 +27,16 @@ main() {
 void main() {
   Uri uri = new Uri(scheme: 'source');
   var compiler = compilerFor(TEST, uri);
-  compiler.runCompiler(uri);
-  var typesInferrer = compiler.typesTask.typesInferrer;
-
-  checkFieldTypeInClass(String className, String fieldName, type) {
-    var cls = findElement(compiler, className);
-    var element = cls.lookupLocalMember(buildSourceString(fieldName));
-    Expect.equals(type, typesInferrer.getTypeOfElement(element));
-  }
-
-  checkFieldTypeInClass('A', 'intField', compiler.typesTask.intType);
-  checkFieldTypeInClass('A', 'stringField', compiler.typesTask.stringType);
+  asyncTest(() => compiler.runCompiler(uri).then((_) {
+    var typesInferrer = compiler.typesTask.typesInferrer;
+
+    checkFieldTypeInClass(String className, String fieldName, type) {
+      var cls = findElement(compiler, className);
+      var element = cls.lookupLocalMember(buildSourceString(fieldName));
+      Expect.equals(type, typesInferrer.getTypeOfElement(element));
+    }
+
+    checkFieldTypeInClass('A', 'intField', compiler.typesTask.intType);
+    checkFieldTypeInClass('A', 'stringField', compiler.typesTask.stringType);
+  }));
 }