Roll Observatory packages and add a roll script

packages/usage/test/src/common.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 usage.common_test;
+
+import 'dart:async';
+
+import 'package:unittest/unittest.dart';
+import 'package:usage/src/usage_impl.dart';
+
+AnalyticsImplMock createMock({bool setOptIn: true}) =>
+    new AnalyticsImplMock('UA-0', setOptIn: setOptIn);
+
+void was(Map m, String type) => expect(m['t'], type);
+void has(Map m, String key) => expect(m[key], isNotNull);
+void hasnt(Map m, String key) => expect(m[key], isNull);
+
+class AnalyticsImplMock extends AnalyticsImpl {
+  MockProperties get mockProperties => properties;
+  MockPostHandler get mockPostHandler => postHandler;
+
+  AnalyticsImplMock(String trackingId, {bool setOptIn: true}) :
+      super(trackingId, new MockProperties(), new MockPostHandler(),
+      applicationName: 'Test App', applicationVersion: '0.1') {
+    if (setOptIn) optIn = true;
+  }
+
+  Map<String, dynamic> get last => mockPostHandler.last;
+}
+
+class MockProperties extends PersistentProperties {
+  Map<String, dynamic> props = {};
+
+  MockProperties() : super('mock');
+
+  dynamic operator[](String key) => props[key];
+
+  void operator[]=(String key, dynamic value) {
+    props[key] = value;
+  }
+}
+
+class MockPostHandler extends PostHandler {
+  List<Map> sentValues = [];
+
+  Future sendPost(String url, Map<String, String> parameters) {
+    sentValues.add(parameters);
+
+    return new Future.value();
+  }
+
+  Map<String, dynamic> get last => sentValues.last;
+}