code: function getFileEntryDisplay(entry) {
          var name = entry.name,
              ext = LanguageManager.getCompoundFileExtension(name),
              i = name.lastIndexOf("." + ext);
  
          if (i > 0) {
              // Escape all HTML-sensitive characters in filename.
              name = _.escape(name.substring(0, i)) + "<span class='extension'>" + _.escape(name.substring(i)) + "</span>";
          } else {
              name = _.escape(name);
          }
  
          return name;
      }
docs: HTML formats a file entry name  for display in the sidebar.
  @param {!File} entry File entry to display
  @return {string} HTML formatted string