Fix analysis server to only send SERVER_STATUS when subscribed to.

pkg/analysis_server/test/analysis_server_test.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.analysis_server;
 
 import 'package:analyzer/file_system/physical_file_system.dart';
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/domain_server.dart';
@@ skipping 16 matching lines @@
       MockSource source = new MockSource();
       source.when(callsTo('get fullName')).alwaysReturn('foo.dart');
       source.when(callsTo('get isInSystemLibrary')).alwaysReturn(false);
       ChangeNoticeImpl notice = new ChangeNoticeImpl(source);
       notice.setErrors([], new LineInfo([0]));
       AnalysisResult firstResult = new AnalysisResult([notice], 0, '', 0);
       AnalysisResult lastResult = new AnalysisResult(null, 1, '', 1);
       context.when(callsTo("performAnalysisTask"))
         ..thenReturn(firstResult, 3)
         ..thenReturn(lastResult);
+      helper.server.serverServices.add(ServerService.STATUS);
       helper.server.schedulePerformAnalysisOperation(context);
       // Pump the event queue to make sure the server has finished any
       // analysis.
       return pumpEventQueue().then((_) {
         List<Notification> notifications = helper.channel.notificationsReceived;
         expect(notifications, isNot(isEmpty));
         // expect at least one notification indicating analysis is in progress
         expect(notifications.any((Notification notification) {
           if (notification.event == SERVER_STATUS) {
             Map analysisStatus = notification.params['analysis'];
@@ skipping 73 matching lines @@
   @override
   Response handleRequest(Request request) {
     if (request.method == 'echo') {
       var response = new Response(request.id);
       response.setResult('echo', true);
       return response;
     }
     return null;
   }
 }