Support for icon theming

sky/sdk/example/widgets/tabs.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/painting/text_style.dart';
 import 'package:sky/theme/typography.dart' as typography;
 import 'package:sky/widgets/basic.dart';
 import 'package:sky/widgets/card.dart';
 import 'package:sky/widgets/scaffold.dart';
 import 'package:sky/widgets/tabs.dart';
@@ skipping 30 matching lines @@
           builder: () => _buildContent(text)
         );
       });
     return _buildTabNavigator(n, views.toList());
   }
 
   TabNavigator _buildIconLabelsTabNavigator(int n) {
     Iterable<TabNavigatorView> views = ["event", "home", "android", "alarm", "face", "language"]
       .map((icon_name) {
         return new TabNavigatorView(
-          label: new TabLabel(icon: "action/${icon_name}_white"),
+          label: new TabLabel(icon: "action/${icon_name}"),
           builder: () => _buildContent(icon_name)
         );
       });
     return _buildTabNavigator(n, views.toList());
   }
 
   TabNavigator _buildTextAndIconLabelsTabNavigator(int n) {
     List<TabNavigatorView> views = <TabNavigatorView>[
       new TabNavigatorView(
-        label: const TabLabel(text: 'STOCKS', icon: 'action/list_white'),
+        label: const TabLabel(text: 'STOCKS', icon: 'action/list'),
         builder: () => _buildContent("Stocks")
       ),
       new TabNavigatorView(
-        label: const TabLabel(text: 'PORTFOLIO', icon: 'action/account_circle_white'),
+        label: const TabLabel(text: 'PORTFOLIO', icon: 'action/account_circle'),
         builder: () => _buildContent("Portfolio")
       ),
       new TabNavigatorView(
-        label: const TabLabel(text: 'SUMMARY', icon: 'action/assessment_white'),
+        label: const TabLabel(text: 'SUMMARY', icon: 'action/assessment'),
         builder: () => _buildContent("Summary")
       )
     ];
     return _buildTabNavigator(n, views);
   }
 
   TabNavigator _buildScrollableTabNavigator(int n) {
     Iterable<TabNavigatorView> views = [
       "MIN WIDTH",
       "THIS TAB LABEL IS SO WIDE THAT IT OCCUPIES TWO LINES",
@@ skipping 54 matching lines @@
     return new Scaffold(
       toolbar: toolbar,
       body: tabNavigator
     );
   }
 }
 
 void main() {
   runApp(new TabbedNavigatorApp());
 }