Add an integration test to verify that server I/O is asynchronous.

pkg/analysis_server/test/timing/timing_framework.dart

 // Copyright (c) 2014, 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 test.timing;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:math';
 
@@ skipping 71 matching lines @@
    * Perform any operations that need to be performed once before any iterations.
    */
   Future oneTimeSetUp() {
     initializeInttestMixin();
     server = new Server();
     sourceDirectory = Directory.systemTemp.createTempSync('analysisServer');
     Completer serverConnected = new Completer();
     onServerConnected.listen((_) {
       serverConnected.complete();
     });
-    return server.start(dispatchNotification).then((params) {
+    return server.start().then((params) {
+      server.listenToOutput(dispatchNotification);
       server.exitCode.then((_) {
         skipShutdown = true;
       });
       return serverConnected.future;
     });
   }
 
   /**
    * Perform any operations that need to be performed before each iteration.
    */
@@ skipping 206 matching lines @@
    */
   List<int> toMilliseconds(List<int> times) {
     int count = times.length;
     List<int> convertedValues = new List<int>();
     for (int i = 0; i < count; i++) {
       convertedValues.add(times[i] ~/ NANOSECONDS_PER_MILLISECOND);
     }
     return convertedValues;
   }
 }