Automatically fetch timeline when timeline page is loaded

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';
+import 'package:observatory/elements.dart';
 import 'package:observatory/service_html.dart';
 import 'package:polymer/polymer.dart';
 
 
 @CustomTag('timeline-page')
 class TimelinePageElement extends ObservatoryElement {
   TimelinePageElement.created() : super.created();
 
   attached() {
     super.attached();
     _resizeSubscription = window.onResize.listen((_) => _updateSize());
     _updateSize();
+    // Click refresh button.
+    NavRefreshElement refreshButton = $['refresh'];
+    refreshButton.buttonClick(null, null, null);
   }
 
   detached() {
     super.detached();
     if (_resizeSubscription != null) {
       _resizeSubscription.cancel();
     }
   }
 
   Future postMessage(String method) {
@@ skipping 50 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;
 }