Fork some more files from the old framework, so that the transition will be easier to perform.

sky/sdk/lib/mojo/net/image_cache.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:sky';
 import 'dart:collection';
+
+import 'package:mojom/mojo/url_response.mojom.dart';
+
 import 'fetch.dart';
-import 'package:mojom/mojo/url_response.mojom.dart';
 
 final HashMap<String, List<ImageDecoderCallback>> _pendingRequests =
   new HashMap<String, List<ImageDecoderCallback>>();
 
 final HashMap<String, Image> _completedRequests =
   new HashMap<String, Image>();
 
 void _loadComplete(url, image) {
   _completedRequests[url] = image;
   _pendingRequests[url].forEach((c) => c(image));
@@ skipping 16 matching lines @@
     fetchUrl(url).then((UrlResponse response) {
       if (response.statusCode >= 400) {
         _loadComplete(url, null);
         return;
       }
       new ImageDecoder(response.body.handle.h,
           (image) => _loadComplete(url, image));
     });
   }
 }