SkyDemo.apk should show thumbmails when offline

sky/sdk/lib/painting/box_painter.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 'dart:async';
 import 'dart:math' as math;
 import 'dart:sky' as sky;
 import 'dart:sky' show Point, Offset, Size, Rect, Color, Paint, Path;
 
 import '../base/lerp.dart';
 import 'shadows.dart';
 import 'package:sky/mojo/net/image_cache.dart' as image_cache;
 
 class BorderSide {
   const BorderSide({
@@ skipping 118 matching lines @@
 enum BackgroundFit { fill, contain, cover, none, scaleDown }
 
 enum BackgroundRepeat { repeat, repeatX, repeatY, noRepeat }
 
 // TODO(jackson): We should abstract this out into a separate class
 // that handles the image caching and so forth, which has callbacks
 // for "size changed" and "image changed". This would also enable us
 // to do animated images.
 
 class BackgroundImage {
-  final String src;
   final BackgroundFit fit;
   final BackgroundRepeat repeat;
   BackgroundImage({
-    this.src,
+    Future<sky.Image> image,
     this.fit: BackgroundFit.scaleDown,
     this.repeat: BackgroundRepeat.noRepeat
   }) {
-    image_cache.load(src).then((image) {
-      if (image == null)
+    image.then((resolvedImage) {
+      if (resolvedImage == null)
         return;
-      _image = image;
-      _size = new Size(image.width.toDouble(), image.height.toDouble());
+      _image = resolvedImage;
+      _size = new Size(resolvedImage.width.toDouble(), resolvedImage.height.toDouble());
       for (Function listener in _listeners) {
         listener();
       }
     });
   }
 
   sky.Image _image;
   sky.Image get image => _image;
 
   Size _size;
 
   final List<Function> _listeners = new List<Function>();
 
   void addChangeListener(Function listener) {
     _listeners.add(listener);
   }
 
   void removeChangeListener(Function listener) {
     _listeners.remove(listener);
   }
 
-  String toString() => 'BackgroundImage($src, $fit, $repeat)';
+  String toString() => 'BackgroundImage($fit, $repeat)';
 }
 
 enum Shape { rectangle, circle }
 
 // This must be immutable, because we won't notice when it changes
 class BoxDecoration {
   const BoxDecoration({
     this.backgroundColor, // null = don't draw background color
     this.backgroundImage, // null = don't draw background image
     this.border, // null = don't draw border
@@ skipping 193 matching lines @@
     path.close();
     canvas.drawPath(path, paint);
   }
 
   void paint(sky.Canvas canvas, Rect rect) {
     _paintBackgroundColor(canvas, rect);
     _paintBackgroundImage(canvas, rect);
     _paintBorder(canvas, rect);
   }
 }