code: function _updateListItemSelection(listItem, selectedFile) {
          var shouldBeSelected = (selectedFile && $(listItem).data(_FILE_KEY).fullPath === selectedFile.fullPath);
          ViewUtils.toggleClass($(listItem), "selected", shouldBeSelected);
      }
docs: Updates the appearance of the list element based on the parameters provided.
  @private
  @param {!HTMLLIElement} listElement
  @param {?File} selectedFile