Make the TaskDescription background color match the ToolBar on Android

sky/sdk/lib/widgets/task_description.dart

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:sky/widgets/widget.dart';
+import 'package:sky/widgets/theme.dart';
+import 'package:sky/mojo/activity.dart' as activity;
+
+class TaskDescription extends Component {
+  Widget child;

[Hixie, 2015/07/07 23:13:03]

these should be final, and after the constructor

+  String label;
+
+  TaskDescription({this.label, this.child});

[Hixie, 2015/07/07 23:13:03]

put spaces inside the {}s around the arguments

+
+  Widget build() {
+    activity.updateTaskDescription(label, Theme.of(this).primaryColor);
+    return child;
+  }
+}