(' + (ratio / 100) + ')';
      progress.style.transform = progress.style.webkitTransform = transform;
    },

    _mainRatioChanged: function(ratio) {
      this._transformProgress(this.$.primaryProgress, ratio);
    },

    _progressChanged: function(secondaryProgress, value, min, max) {
      secondaryProgress = this._clampValue(secondaryProgress);
      value = this._clampValue(value);

      var secondaryRatio = this._calcRatio(secondaryProgress) * 100;
      var mainRatio = this._calcRatio(value) * 10