Support stacktrace and objecthistogram service commands

tests/standalone/vmservice/unknown_isolate_command_test.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=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 //
 // Test:
 //   *) Connect to VM Service and obtain list of running isolates.
 
-library isolate_list_test;
+library unknown_isolate_command_test;
 
 import 'test_helper.dart';
 import 'package:expect/expect.dart';
 
+class UnknownRequestTest extends VmServiceRequestHelper {
+  UnknownRequestTest(port, id) :
+      super('http://127.0.0.1:$port/isolates/$id/badrequest');
+
+  onRequestCompleted(Map reply) {
+    Expect.equals('error', reply['type']);
+  }
+}
 
 class IsolateListTest extends VmServiceRequestHelper {
   IsolateListTest(port) : super('http://127.0.0.1:$port/isolates');
 
+  int _isolateId;
   onRequestCompleted(Map reply) {
     IsolateListTester tester = new IsolateListTester(reply);
     tester.checkIsolateCount(1);
-    tester.checkIsolateNameContains('isolate_list_script.dart');
+    tester.checkIsolateNameContains('unknown_isolate_command_script.dart');
+    _isolateId = reply['members'][0]['id'];
   }
 }
 
 
 main() {
-  var process = new TestLauncher('isolate_list_script.dart');
+  var process = new TestLauncher('unknown_isolate_command_script.dart');
   process.launch().then((port) {
     var test = new IsolateListTest(port);
     test.makeRequest().then((_) {
-      process.requestExit();
+      var unknownRequestTest = new UnknownRequestTest(port, test._isolateId);
+      unknownRequestTest.makeRequest().then((_) {
+        process.requestExit();
+      });
     });
   });
 }