ressChanged(secondaryProgress, value, min, max)'
    ],

    hostAttributes: {
      role: 'progressbar'
    },

    _toggleIndeterminate: function(indeterminate) {
      // If we use attribute/class binding, the animation sometimes doesn't translate properly
      // on Safari 7.1. So instead, we toggle the class here in the update method.
      this.toggleClass('indeterminate', indeterminate, this.$.primaryProgress);
    },

    _transformProgress: function(progress, ratio) {
      var transform = 'scaleX