Converted Observatory heap-profile element

runtime/observatory/lib/src/elements/isolate/counter_chart.dart

Index: runtime/observatory/lib/src/elements/isolate/counter_chart.dart
diff --git a/runtime/observatory/lib/src/elements/isolate/counter_chart.dart b/runtime/observatory/lib/src/elements/isolate/counter_chart.dart
index 3c7b3bc4c3f431a4368f397fb08aa64f4b47e9d0..14bc7ef66f37611f07d4c4b288946c6246f4c812 100644
--- a/runtime/observatory/lib/src/elements/isolate/counter_chart.dart
+++ b/runtime/observatory/lib/src/elements/isolate/counter_chart.dart
@@ -46,30 +46,30 @@ class IsolateCounterChartElement extends HtmlElement implements Renderable {
     _subscription.cancel();
   }
 
+  static final _columns = [
+    new ChartColumnSpec(label: 'Type', type: ChartColumnSpec.TYPE_STRING),
+    new ChartColumnSpec(label: 'Percent', formatter: (v) => v.toString())
+  ];
+
+  final _series = [new ChartSeries("Work", const [1], new PieChartRenderer(
+    sortDataByValue: false
+  ))];
+
   void render() {
-    var areaHost;
-    var legendHost;
-    children = [
-      areaHost = new DivElement()..classes = ['host'],
-      legendHost = new DivElement()..classes = ['legend']
-    ];
-    final series = new ChartSeries("Work", [1], new PieChartRenderer(
-      sortDataByValue: false
-    ));
-    var rect = areaHost.getBoundingClientRect();
-    var minSize = new Rect.size(rect.width, rect.height);
-    final config = new ChartConfig([series], [0])
+    final areaHost = new DivElement()..classes = const ['host'];
+    final  legendHost = new DivElement()..classes = const ['legend'];
+    children = [areaHost, legendHost];
+    final rect = areaHost.getBoundingClientRect();
+    final minSize = new Rect.size(rect.width, rect.height);
+    final config = new ChartConfig(_series, const [0])
         ..minimumSize = minSize
         ..legend = new ChartLegend(legendHost, showValues: true);
-    final data = new ChartData([
-        new ChartColumnSpec(label: 'Type', type: ChartColumnSpec.TYPE_STRING),
-        new ChartColumnSpec(label: 'Percent', formatter: (v) => v.toString())
-      ], _counters.keys
+    final data = new ChartData(_columns, _counters.keys
           .map((key) => [key, double.parse(_counters[key].split('%')[0])])
           .toList());
 
     new LayoutArea(areaHost, data, config, state: new ChartState(),
-        autoUpdate: true)
+        autoUpdate: false)
       ..addChartBehavior(new Hovercard())
       ..addChartBehavior(new AxisLabelTooltip())
       ..draw();