Add the streamListen and streamCancel rpcs to the vm service.

runtime/observatory/tests/service/coverage_test.dart

 // Copyright (c) 2015, 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.
 // VMOptions=--compile-all --error_on_bad_type --error_on_bad_override
 
 import 'package:observatory/service_io.dart';
 import 'package:unittest/unittest.dart';
 import 'test_helper.dart';
 import 'dart:async';
 
@@ skipping 39 matching lines @@
   return normalized;
 }
 
 var tests = [
 
 // Go to breakpoint at line 14.
 (Isolate isolate) {
   return isolate.rootLibrary.load().then((_) {
       // Set up a listener to wait for breakpoint events.
       Completer completer = new Completer();
-      isolate.vm.events.stream.listen((ServiceEvent event) {
+      isolate.vm.debugEvents.listen((ServiceEvent event) {
         if (event.eventType == ServiceEvent.kPauseBreakpoint) {
           print('Breakpoint reached');
           completer.complete();
         }
       });
 
       // Create a timer to set a breakpoint with a short delay.
       new Timer(new Duration(milliseconds: 2000), () {
         // Add the breakpoint.
         print('Setting breakpoint.');
@@ skipping 75 matching lines @@
                     expect(coverage['coverage'].length, greaterThan(100));
                 });
           }));
       return Future.wait(tests);
   });
 },
 
 ];
 
 main(args) => runIsolateTests(args, tests, testeeConcurrent: testFunction);