Update charted to 0.4.8 and roll

packages/usage/lib/src/usage_impl_html.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_html;
-
 import 'dart:async';
 import 'dart:convert' show JSON;
 import 'dart:html';
 
 import 'usage_impl.dart';
 
+/// An interface to a Google Analytics session, suitable for use in web apps.
+///
+/// [analyticsUrl] is an optional replacement for the default Google Analytics
+/// URL (`https://www.google-analytics.com/collect`).
+class AnalyticsHtml extends AnalyticsImpl {
+  AnalyticsHtml(
+      String trackingId, String applicationName, String applicationVersion,
+      {String analyticsUrl})
+      : super(trackingId, new HtmlPersistentProperties(applicationName),
+            new HtmlPostHandler(),
+            applicationName: applicationName,
+            applicationVersion: applicationVersion,
+            analyticsUrl: analyticsUrl) {
+    int screenWidth = window.screen.width;
+    int screenHeight = window.screen.height;
+
+    setSessionValue('sr', '${screenWidth}x$screenHeight');
+    setSessionValue('sd', '${window.screen.pixelDepth}-bits');
+    setSessionValue('ul', window.navigator.language);
+  }
+}
+
+typedef Future<HttpRequest> HttpRequestor(String url,
+    {String method, sendData});
+
 class HtmlPostHandler extends PostHandler {
-  final Function mockRequestor;
+  final HttpRequestor mockRequestor;
 
-  HtmlPostHandler({Function this.mockRequestor});
+  HtmlPostHandler({this.mockRequestor});
 
+  @override
   Future sendPost(String url, Map<String, dynamic> parameters) {
     int viewportWidth = document.documentElement.clientWidth;
     int viewportHeight = document.documentElement.clientHeight;
 
     parameters['vp'] = '${viewportWidth}x$viewportHeight';
 
     String data = postEncode(parameters);
-    var request = mockRequestor == null ? HttpRequest.request : mockRequestor;
-    return request(url, method: 'POST', sendData: data).catchError((e) {
+    HttpRequestor requestor =
+        mockRequestor == null ? HttpRequest.request : mockRequestor;
+    return requestor(url, method: 'POST', sendData: data).catchError((e) {
       // Catch errors that can happen during a request, but that we can't do
-      // anything about, e.g. a missing internet conenction.
+      // anything about, e.g. a missing internet connection.
     });
   }
+
+  @override
+  void close() {}
 }
 
 class HtmlPersistentProperties extends PersistentProperties {
   Map _map;
 
   HtmlPersistentProperties(String name) : super(name) {
     String str = window.localStorage[name];
     if (str == null || str.isEmpty) str = '{}';
     _map = JSON.decode(str);
   }
 
-  dynamic operator[](String key) => _map[key];
+  @override
+  dynamic operator [](String key) => _map[key];
 
-  void operator[]=(String key, dynamic value) {
+  @override
+  void operator []=(String key, dynamic value) {
     if (value == null) {
       _map.remove(key);
     } else {
       _map[key] = value;
     }
 
     window.localStorage[name] = JSON.encode(_map);
   }
+
+  @override
+  void syncSettings() {}
 }