Update charted to 0.4.8 and roll

packages/quiver/test/async/countdown_timer_test.dart

 // Copyright 2013 Google Inc. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 10 matching lines @@
 import 'package:quiver/testing/time.dart';
 
 main() {
   group('CountdownTimer', () {
     test('should countdown', () {
       new FakeAsync().run((FakeAsync async) {
         var clock = async.getClock(new DateTime.fromMillisecondsSinceEpoch(0));
         var stopwatch = new FakeStopwatch(
             () => 1000 * clock.now().millisecondsSinceEpoch, 1000000);
 
-        var timings = new CountdownTimer(
-            new Duration(milliseconds: 500), new Duration(milliseconds: 100),
-            stopwatch: stopwatch).map((c) => c.remaining.inMilliseconds);
+        var timings = new CountdownTimer(const Duration(milliseconds: 500),
+                const Duration(milliseconds: 100),
+                stopwatch: stopwatch)
+            .map((c) => c.remaining.inMilliseconds);
 
         List<int> result;
         timings.toList().then((list) {
           result = list;
         });
 
         async.elapse(aMillisecond * 500);
         expect(result, [400, 300, 200, 100, 0]);
       });
     });
+
+    test('should set increment to the initialized value', () {
+      var timer = new CountdownTimer(
+          const Duration(milliseconds: 321), const Duration(milliseconds: 123));
+      expect(timer.increment, const Duration(milliseconds: 123));
+    });
   });
 }