Use package:sky imports consistently

sky/sdk/lib/widgets/tool_bar.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/theme.dart';
 
-import '../painting/text_style.dart';
-import '../rendering/flex.dart';
-import '../theme/shadows.dart';
-import '../theme/typography.dart' as typography;
-import '../theme/view_configuration.dart';
-import 'basic.dart';
-import 'default_text_style.dart';
-import 'icon.dart';
+import 'package:sky/painting/text_style.dart';
+import 'package:sky/rendering/flex.dart';
+import 'package:sky/theme/shadows.dart';
+import 'package:sky/theme/typography.dart' as typography;
+import 'package:sky/theme/view_configuration.dart';
+import 'package:sky/widgets/basic.dart';
+import 'package:sky/widgets/default_text_style.dart';
+import 'package:sky/widgets/icon.dart';
 
 class ToolBar extends Component {
 
   ToolBar({
     String key,
     this.left,
     this.center,
     this.right,
     this.backgroundColor
   }) : super(key: key);
@@ skipping 50 matching lines @@
         boxShadow: shadows[2]
       )
     );
 
     if (iconThemeData != null)
       content = new IconTheme(data: iconThemeData, child: content);
     return content;
   }
 
 }