Roll Observatory deps (charted -> ^0.3.0)

packages/usage/test/usage_impl_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 usage.impl_test;
 
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 import 'package:usage/src/usage_impl.dart';
 
 import 'src/common.dart';
 
+main() => defineTests();
+
 void defineTests() {
   group('ThrottlingBucket', () {
     test('can send', () {
       ThrottlingBucket bucket = new ThrottlingBucket(20);
       expect(bucket.removeDrop(), true);
     });
 
     test('doesn\'t send too many', () {
       ThrottlingBucket bucket = new ThrottlingBucket(20);
       for (int i = 0; i < 20; i++) {
@@ skipping 35 matching lines @@
       AnalyticsImplMock mock = createMock();
       mock.sendScreenView('foo');
       mock.sendScreenView('bar');
       mock.sendScreenView('baz');
       return mock.waitForLastPing(timeout: new Duration(milliseconds: 100));
     });
   });
 
   group('postEncode', () {
     test('simple', () {
-      Map map = {'foo': 'bar', 'baz': 'qux norf'};
+      Map<String, dynamic> map = {'foo': 'bar', 'baz': 'qux norf'};
       expect(postEncode(map), 'foo=bar&baz=qux%20norf');
     });
   });
 }