Switch build mode to Analysis Driver.

pkg/analyzer_cli/test/build_mode_test.dart

Index: pkg/analyzer_cli/test/build_mode_test.dart
diff --git a/pkg/analyzer_cli/test/build_mode_test.dart b/pkg/analyzer_cli/test/build_mode_test.dart
index a80a072f72f0de09d5a8f871bd0c54729bb97f3e..6ccff0d657d0152258aa7570ebd3f24c3f8ef0cd 100644
--- a/pkg/analyzer_cli/test/build_mode_test.dart
+++ b/pkg/analyzer_cli/test/build_mode_test.dart
@@ -4,6 +4,8 @@
 
 library analyzer_cli.test.built_mode;
 
+import 'dart:async';
+
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer_cli/src/build_mode.dart';
 import 'package:analyzer_cli/src/driver.dart';
@@ -30,7 +32,7 @@ class TestAnalyzerWorkerLoop extends AnalyzerWorkerLoop {
       : super(new MemoryResourceProvider(), connection);
 
   @override
-  void analyze(CommandLineOptions options) {
+  Future<Null> analyze(CommandLineOptions options) async {
     if (_analyze != null) {
       _analyze(options);
     }