Upgrade Observatory to Polymer 0.10.x

runtime/bin/vmservice/client/lib/src/elements/isolate_summary.dart

 // Copyright (c) 2013, 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 isolate_summary_element;
 
 import 'dart:async';
 import 'dart:html';
 import 'observatory_element.dart';
 import 'package:observatory/app.dart';
@@ skipping 71 matching lines @@
     }
     _chart.draw(_table);
   }
 }
 
 @CustomTag('isolate-counter-chart')
 class IsolateCounterChartElement extends ObservatoryElement {
   IsolateCounterChartElement.created() : super.created();
 
   @published ObservableMap counters;
-  CounterChart chart = new CounterChart();
+  CounterChart chart;
 
   void countersChanged(oldValue) {
     if (counters == null) {
       return;
     }
+    // Lazily create the chart.
+    if (GoogleChart.ready && chart == null) {
+      chart = new CounterChart();
+    }
+    if (chart == null) {
+      return;
+    }
     chart.update(counters);
     var element = shadowRoot.querySelector('#counterPieChart');
     if (element != null) {
       chart.draw(element);
     }
   }
 }