First pass at asynchronous input loading in dart2js.

tests/compiler/dart2js/types_of_captured_variables_test.dart

Index: tests/compiler/dart2js/types_of_captured_variables_test.dart
diff --git a/tests/compiler/dart2js/types_of_captured_variables_test.dart b/tests/compiler/dart2js/types_of_captured_variables_test.dart
index 3376b657066adc67bae04f297248409cd650cc75..e46f23c58727d177e28ac84641187be425fbcd62 100644
--- a/tests/compiler/dart2js/types_of_captured_variables_test.dart
+++ b/tests/compiler/dart2js/types_of_captured_variables_test.dart
@@ -35,15 +35,18 @@ main() {
 
 main() {
   // Test that we know the type of captured, non-mutated variables.
-  String generated = compileAll(TEST1);
-  Expect.isTrue(generated.contains('+ 3'));
+  compileAll(TEST1).then((generated) {
+    Expect.isTrue(generated.contains('+ 3'));
+  });
 
   // Test that we know the type of captured, mutated variables.
-  generated = compileAll(TEST2);
-  Expect.isTrue(generated.contains('+ 3'));
+  compileAll(TEST2).then((generated) {
+    Expect.isTrue(generated.contains('+ 3'));
+  });
 
   // Test that we know when types of a captured, mutated variable
   // conflict.
-  generated = compileAll(TEST3);
-  Expect.isFalse(generated.contains('+ 3'));
+  compileAll(TEST3).then((generated) {
+    Expect.isFalse(generated.contains('+ 3'));
+  });
 }