    const metricSelector = tr.ui.b.createSelector(
          this, 'currentMetricName_',
          this.settingsKey_,
          this.currentMetricName_,
          this.metrics_);
      Polymer.dom(this.$.top_left_controls).appendChild(metricSelector);
      metricSelector.addEventListener('change',
          this.onMetricChange_.bind(this));
      this.currentMetricTypeInfo_ =
        tr.metrics.MetricRegistry.findTypeInfoWithName(
            this.currentMetricName_);

      this.recomputeButton_ = tr.ui.b