Add a missing type name.

sdk/lib/_internal/pub/lib/src/barback.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library pub.barback;
 
 import 'dart:async';
 
 import 'package:barback/barback.dart';
 import 'package:path/path.dart' as path;
@@ skipping 101 matching lines @@
     BarbackMode mode, {Iterable<Transformer> builtInTransformers,
     WatcherType watcher: WatcherType.AUTO}) {
   var provider = new PubPackageProvider(graph);
   var barback = new Barback(provider);
 
   barback.log.listen(_log);
 
   return BarbackServer.bind(host, port, barback, graph.entrypoint.root.name)
       .then((server) {
     return new Future.sync(() {
-      if (watcher == WatcherType.NONE) {
-        loadSources(graph, barback);
-        return;
+      if (watcher != WatcherType.NONE) {
+        return watchSources(graph, barback, watcher);
       }
 
-      return watchSources(graph, barback, (directory) {
-        if (watcher == WatcherType.AUTO) return new DirectoryWatcher(directory);
-        return new PollingDirectoryWatcher(directory);
-      });
+      loadSources(graph, barback);
     }).then((_) {
       var completer = new Completer();
 
       // If any errors get emitted either by barback or by the server, including
       // non-programmatic barback errors, they should take down the whole
       // program.
       var subscriptions = [
         server.barback.errors.listen((error) {
           if (error is TransformerException) error = error.error;
           if (!completer.isCompleted) completer.completeError(error);
@@ skipping 164 matching lines @@
 
     case LogLevel.WARNING:
       log.warning("${log.yellow(prefix)}\n$message");
       break;
 
     case LogLevel.INFO:
       log.message("$prefix\n$message");
       break;
   }
 }