chart-bar suggested fix for not rendering

chart-bar.html

<link rel="import" href="../polymer/polymer.html">
<link rel="import" href="chart-js-import.html">
<link rel="import" href="dataset-properties-behavior.html">
<link rel="import" href="context-behavior.html">
<link rel="import" href="resize-behavior.html">
<link rel="import" href="chart-styles.html">

<dom-module id="chart-bar">

  <template>

    <style include="chart-styles"></style>

    <canvas id="canvas"></canvas>

  </template>

  <script>
    Polymer({

      is: 'chart-bar',

      behaviors: [
        ChartBehaviors.DatasetPropertiesBehavior,
        ChartBehaviors.ContextBehavior,
        ChartBehaviors.ResizeBehavior
      ],

      updateChart: function () {

        if(this.isAttached){ //Check for attach otherwise our ctx and chart will be undefined, resulting in no render
          this.async(function () {

            if (this.chart) {
              this.chart.destroy();
            }

            this.async(function() {
              this.chart = new Chart(this.ctx).Bar(this.data, this.options);
            }, null, 0);

          }, null, 0);
        } else {
          console.log("udpateChart() DOM isn't ready!");
        }
      },

      //Always called after ready, which means our canvas element will exist
      //This enables us to render the chart the first time on page load an retain our update method for updates
      attached: function() {
        this.updateChart();
      },

    });
  </script>

</dom-module>