gistfile1.txt

 class SystemAddonInstallLocation extends DirectoryInstallLocation {
  /**
   * @param  aName
   *         The string identifier for the install location
   * @param  aDirectory
   *         The nsIFile directory for the install location
   * @param  aScope
   *         The scope of add-ons installed in this location
   * @param  aResetSet
   *         True to throw away the current add-on set
   */
  constructor(aName, aDirectory, aScope, aResetSet) {
    let _addonSet = SystemAddonInstallLocation._loadAddonSet();
    let _directory = null;
    if (_addonSet.directory) {
      _directory = aDirectory.clone();
      _directory.append(_addonSet.directory);
      logger.info("SystemAddonInstallLocation scanning directory " + _directory.path);
    }
    else {
      logger.info("SystemAddonInstallLocation directory is missing");
    }
    super(aName, _directory, aScope);

    this._directory = _directory;
    this._baseDir = aDirectory;
    this._nextDir = null;

    this._stagingDirLock = 0;

    if (aResetSet) {
      this.resetAddonSet();
    }

    this.locked = false;
  }