Update charted to 0.4.8 and roll

packages/usage/example/ga.dart

Index: packages/usage/example/ga.dart
diff --git a/packages/usage/example/ga.dart b/packages/usage/example/ga.dart
index dcd91106b02b1c1c29712b6952c8906625881be4..ad64249fff1c97c61e0099f13030623b225d86f0 100644
--- a/packages/usage/example/ga.dart
+++ b/packages/usage/example/ga.dart
@@ -2,14 +2,12 @@
 // 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.
 
-/**
- * A simple command-line app to hand-test the usage library.
- */
+/// A simple command-line app to hand-test the usage library.
 library usage_ga;
 
 import 'package:usage/usage_io.dart';
 
-void main(List args) {
+main(List args) async {
   final String DEFAULT_UA = 'UA-55029513-1';
 
   if (args.isEmpty) {
@@ -21,18 +19,17 @@ void main(List args) {
 
   String ua = args.isEmpty ? DEFAULT_UA : args.first;
 
-  Analytics ga = new AnalyticsIO(ua, 'ga_test', '1.0');
-  ga.optIn = true;
-
-  ga.sendScreenView('home').then((_) {
-    return ga.sendScreenView('files');
-  }).then((_) {
-    return ga.sendException('foo exception, line 123:56');
-  }).then((_) {
-    return ga.sendTiming('writeDuration', 123);
-  }).then((_) {
-    return ga.sendEvent('create', 'consoleapp', label: 'Console App');
-  }).then((_) {
-    print('pinged ${ua}');
-  });
+  Analytics ga = new AnalyticsIO(ua, 'ga_test', '3.0');
+
+  await ga.sendScreenView('home');
+  await ga.sendScreenView('files');
+  await ga
+      .sendException('foo error:\n${sanitizeStacktrace(StackTrace.current)}');
+  await ga.sendTiming('writeDuration', 123);
+  await ga.sendEvent('create', 'consoleapp', label: 'Console App');
+  print('pinged ${ua}');
+
+  await ga.waitForLastPing();
+
+  ga.close();
 }