First pass at asynchronous input loading in dart2js.

tests/compiler/dart2js/analyze_api_test.dart

Index: tests/compiler/dart2js/analyze_api_test.dart
diff --git a/tests/compiler/dart2js/analyze_api_test.dart b/tests/compiler/dart2js/analyze_api_test.dart
index ec291dd622a0450027f67e1f8d5fee34ea34680d..7194e5c24176890b77f34811f18d891ab0d93c7d 100644
--- a/tests/compiler/dart2js/analyze_api_test.dart
+++ b/tests/compiler/dart2js/analyze_api_test.dart
@@ -6,6 +6,7 @@ library analyze_api;
 
 import '../../../sdk/lib/_internal/libraries.dart';
 import 'analyze_helper.dart';
+import "../../async_helper.dart";
 
 /**
  * Map of white-listed warnings and errors.
@@ -28,5 +29,5 @@ void main() {
       uriList.add(new Uri(scheme: 'dart', path: name));
     }
   });
-  analyze(uriList, WHITE_LIST);
+  asyncTest(() => analyze(uriList, WHITE_LIST));
 }