Update charted to 0.4.8 and roll

packages/unittest/test/expect_async_args_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.
 
 library unittest.expect_async_args_test;
 
 import 'package:unittest/unittest.dart';
 
 import 'package:metatest/metatest.dart';
 
 void main() => initTests(_test);
 
 void _test(message) {
   initMetatest(message);
 
   expectTestResults('expect async args', () {
     var count = 0;
     List<int> _getArgs([a = 0, b = 0, c = 0, d = 0, e = 0, f = 0]) {
       count++;
-      return [a, b, c, d, e, f];
+      return <int>[a, b, c, d, e, f];
     }
 
     test('expect async args', () {
       expect(expectAsync(_getArgs)(), [0, 0, 0, 0, 0, 0]);
       expect(expectAsync(_getArgs)(5), [5, 0, 0, 0, 0, 0]);
       expect(expectAsync(_getArgs)(1, 2, 3, 4, 5, 6), [1, 2, 3, 4, 5, 6]);
     });
 
     test('invoked with too many args', () {
       expectAsync(_getArgs)(1, 2, 3, 4, 5, 6, 7);
     });
 
     test('created with too many args', () {
       expectAsync((a1, a2, a3, a4, a5, a6, a7) {
         count++;
       })();
     });
 
     test('verify count', () {
       expect(count, 3);
     });
   }, [
     {'description': 'expect async args', 'result': 'pass',},
     {'description': 'invoked with too many args', 'result': 'error',},
     {'description': 'created with too many args', 'result': 'error',},
     {'description': 'verify count', 'result': 'pass',}
   ]);
 }