Collect samples for background threads.

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

 // Copyright (c) 2015, 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 timeline_page_element;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:html';
 import 'observatory_element.dart';
@@ skipping 29 matching lines @@
       'params': {
         'vmAddress': (app.vm as WebSocketVM).target.networkAddress,
         'isolateIds': isolateIds
       }
     };
     e.contentWindow.postMessage(JSON.encode(message), window.location.href);
     return null;
   }
 
   Future refresh() async {
+    await app.vm.reload();
+    await app.vm.reloadIsolates();
     return postMessage('refresh');
   }
 
   Future clear() async {
     await app.vm.invokeRpc('_clearVMTimeline', {});
     return postMessage('clear');
   }
 
   Future recordOn() async {
     return app.vm.invokeRpc('_setVMTimelineFlags', {
@@ skipping 21 matching lines @@
     final top = e.offset.top;
     final bottomMargin = 32;
     final mainHeight = totalHeight - top - bottomMargin;
     e.style.setProperty('height', '${mainHeight}px');
     e.style.setProperty('width', '100%');
   }
 
 
   StreamSubscription _resizeSubscription;
 }