Rank most retaining instances for each class.

runtime/observatory/lib/src/elements/heap_profile.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library heap_profile_element;
 
 import 'dart:html';
 import 'observatory_element.dart';
 import 'package:observatory/app.dart';
 import 'package:observatory/service.dart';
@@ skipping 81 matching lines @@
         shadowRoot.querySelector('#newPieChart'));
     _oldPieChart = new Chart('PieChart',
         shadowRoot.querySelector('#oldPieChart'));
     _classTableBody = shadowRoot.querySelector('#classTableBody');
     _subscription = app.vm.events.stream.where(
         (event) => event.isolate == isolate).listen(_onEvent);
   }
 
   @override
   void detached() {
-    _subscription.cancel((){});
+    _subscription.cancel();
     super.detached();
   }
   
   void _onEvent(ServiceEvent event) {
     if (autoRefresh && event.eventType == 'GC') {
       refresh((){});
     }
   }
   
   void _updatePieCharts() {
@@ skipping 219 matching lines @@
   }
 
   @observable String formattedTotalCollectionTime(bool newSpace) {
     if (profile == null) {
       return '';
     }
     var heap = newSpace ? profile.isolate.newSpace : profile.isolate.oldSpace;
     return '${Utils.formatSeconds(heap.totalCollectionTimeInSeconds)} secs';
   }
 }