code: function(bounds, zoomChanged, dragging) {
          if (zoomChanged || !this.matrix) {
              this.updateMatrixProperties();
          }
          return OpenLayers.Layer.Grid.prototype.moveTo.apply(this, arguments);
      }
docs: Method: moveTo
  
  Parameters:
  bounds - {<OpenLayers.Bounds>}
  zoomChanged - {Boolean} Tells when zoom has changed, as layers have to
  do some init work in that case.
  dragging - {Boolean}