Implement 'print', 'up', 'down', and 'frame' commands in the Observatory debugger.

runtime/observatory/test/debugging_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.
 
 import 'package:observatory/service_io.dart';
 import 'package:unittest/unittest.dart';
 import 'test_helper.dart';
 import 'dart:async';
 
 void helper(i) {
   print(i);
 }
 
 void testFunction() {
   int i = 0;
   while (true) {
     if (++i % 100000000 == 0) {
       helper(i);  // line 18
     }
   }
 }
 
 var tests = [
 
 // Pause
 (Isolate isolate) {
   Completer completer = new Completer();
-  isolate.vm.events.stream.listen((ServiceEvent event) {
+  var subscription;
+  subscription = isolate.vm.events.stream.listen((ServiceEvent event) {
     if (event.eventType == ServiceEvent.kPauseInterrupted) {
+      subscription.cancel();
       completer.complete();
     }
   });
   isolate.pause();
   return completer.future;
 },
 
 // Resume
 (Isolate isolate) {
-  return isolate.resume().then((_) {
-      expect(isolate.pauseEvent.eventType, equals(ServiceEvent.kResume));
-      expect(isolate.running, isTrue);
-      expect(isolate.paused, isFalse);
+  Completer completer = new Completer();
+  var subscription;
+  subscription = isolate.vm.events.stream.listen((ServiceEvent event) {
+    if (event.eventType == ServiceEvent.kResume) {
+      subscription.cancel();
+      completer.complete();
+    }
   });
+  isolate.resume();
+  return completer.future;
 },
 
 // Add breakpoint
 (Isolate isolate) {
   return isolate.rootLib.load().then((_) {
       // Set up a listener to wait for breakpoint events.
       Completer completer = new Completer();
       List events = [];
       var subscription;
       subscription = isolate.vm.events.stream.listen((ServiceEvent event) {
@@ skipping 72 matching lines @@
 
   expect(isolate.breakpoints.length, equals(1));
   var bpt = isolate.breakpoints.values.first;
   return isolate.removeBreakpoint(bpt).then((_) {
     return completer.future;
   });
 },
 
 // Resume
 (Isolate isolate) {
-  return isolate.resume().then((_) {
-      expect(isolate.pauseEvent.eventType, equals(ServiceEvent.kResume));
-      expect(isolate.running, isTrue);
-      expect(isolate.paused, isFalse);
+  Completer completer = new Completer();
+  var subscription;
+  subscription = isolate.vm.events.stream.listen((ServiceEvent event) {
+    if (event.eventType == ServiceEvent.kResume) {
+      subscription.cancel();
+      completer.complete();
+    }
   });
+  isolate.resume();
+  return completer.future;
 },
 
 // Add breakpoint at function entry
 (Isolate isolate) {
   // Set up a listener to wait for breakpoint events.
   Completer completer = new Completer();
   List events = [];
   var subscription;
   subscription = isolate.vm.events.stream.listen((ServiceEvent event) {
     if (event.eventType == ServiceEvent.kPauseBreakpoint) {
@@ skipping 16 matching lines @@
     expect(bpt.script.name, equals('debugging_test.dart'));
     expect(bpt.tokenPos, equals(29));
     expect(isolate.breakpoints.length, equals(1));
     return completer.future;  // Wait for breakpoint events.
   });
 },
 
 ];
 
 main(args) => runIsolateTests(args, tests, testeeConcurrent: testFunction);