Port metrics test to new framework.

runtime/bin/vmservice/observatory/test/metrics_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 allocations_test;
+
+import 'test_helper.dart';
+import 'package:observatory/service_io.dart';
+import 'package:unittest/unittest.dart';
+
+import 'dart:io';
+
+main() {
+  String script = 'metrics_script.dart';
+  var process = new TestLauncher(script);
+  process.launch().then((port) {
+    String addr = 'ws://localhost:$port/ws';
+    new WebSocketVM(new WebSocketVMTarget(addr)).get('vm')
+        .then((VM vm) => vm.isolates.first.load())
+        .then((Isolate isolate) =>
+          isolate.get('metrics').then((ServiceMap metrics) {
+            expect(metrics['type'], equals('MetricList'));
+            var members = metrics['members'];
+            expect(members, isList);
+            expect(members.length, equals(1));
+            var counter = members[0];
+            expect(counter['name'], equals('a.b.c'));
+            expect(counter['value'], equals(1234.5));
+            return isolate;
+          }))
+        .then((Isolate isolate) =>
+          isolate.get('metrics/a.b.c').then((ServiceMap counter) {
+            expect(counter['name'], equals('a.b.c'));
+            expect(counter['value'], equals(1234.5));
+            return isolate;
+          }))
+        .then((Isolate isolate) =>
+          isolate.get('metrics/a.b.c.d').then((DartError err) {
+            expect(err is DartError, isTrue);
+            return isolate;
+          }))
+        .then((Isolate isolate) => exit(0));
+  });
+}