Make VM event streams look like real dart streams.

runtime/observatory/tests/service/test_helper.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.
 // VMOptions=--compile-all --error_on_bad_type --error_on_bad_override --checked
 
 library test_helper;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
@@ skipping 123 matching lines @@
   }
 }
 
 
 // Cancel the subscription and complete the completer when finished processing
 // events.
 typedef void ServiceEventHandler(ServiceEvent event,
                                  StreamSubscription subscription,
                                  Completer completer);
 
-Future processServiceEvents(VM vm, ServiceEventHandler handler) {
+Future processServiceEvents(VM vm,
+                            String streamId,
+                            ServiceEventHandler handler) {
   Completer completer = new Completer();
-  var subscription;
-  subscription = vm.events.stream.listen((ServiceEvent event) {
-    handler(event, subscription, completer);
+  vm.getEventStream(streamId).then((stream) {
+    var subscription;
+    subscription = stream.listen((ServiceEvent event) {
+      handler(event, subscription, completer);
+    });
   });
   return completer.future;
 }
 
 
 Future<Isolate> hasStoppedAtBreakpoint(Isolate isolate) {
   if ((isolate.pauseEvent != null) &&
       (isolate.pauseEvent.kind == ServiceEvent.kPauseBreakpoint)) {
     // Already waiting at a breakpoint.
     print('Breakpoint reached');
     return new Future.value(isolate);
   }
 
   // Set up a listener to wait for breakpoint events.
   Completer completer = new Completer();
-  var subscription;
-  subscription = isolate.vm.events.stream.listen((ServiceEvent event) {
-    if (event.kind == ServiceEvent.kPauseBreakpoint) {
-      print('Breakpoint reached');
-      subscription.cancel();
-      completer.complete(isolate);
-    }
+  isolate.vm.getEventStream(VM.kDebugStream).then((stream) {
+    var subscription;
+    subscription = stream.listen((ServiceEvent event) {
+        if (event.kind == ServiceEvent.kPauseBreakpoint) {
+          print('Breakpoint reached');
+          subscription.cancel();
+          completer.complete();
+        }
+    });
   });
 
   return completer.future;  // Will complete when breakpoint hit.
 }
 
 
 Future<Isolate> resumeIsolate(Isolate isolate) {
   Completer completer = new Completer();
-  var subscription;
-  subscription = isolate.vm.events.stream.listen((ServiceEvent event) {
-    if (event.kind == ServiceEvent.kResume) {
-      subscription.cancel();
-      completer.complete();
-    }
+  isolate.vm.getEventStream(VM.kDebugStream).then((stream) {
+    var subscription;
+    subscription = stream.listen((ServiceEvent event) {
+      if (event.kind == ServiceEvent.kResume) {
+        subscription.cancel();
+        completer.complete();
+      }
+    });
   });
   isolate.resume();
   return completer.future;
 }
 
 
 /// Runs [tests] in sequence, each of which should take an [Isolate] and
 /// return a [Future]. Code for setting up state can run before and/or
 /// concurrently with the tests. Uses [mainArgs] to determine whether
 /// to run tests or testee in this invokation of the script.
@@ skipping 32 matching lines @@
       }, onError: (e, st) {
         process.requestExit();
         if (!_isWebSocketDisconnect(e)) {
           print('Unexpected exception in service tests: $e $st');
           throw e;
         }
       });
     });
   }
 }