anchor.diff:    /// Restore Chrome user information from a per-project cache into Chrome's
     /// user data directory.
     void _restoreUserSessionInformation(Directory cacheDir, Directory userDataDir) {
  -    final Directory sourceChromeDefault = _fileSystem.directory(_fileSystem.path.join(cacheDir.path ?? '', _chromeDefaultPath));
  +    final Directory sourceChromeDefault = _fileSystem.directory(_fileSystem.path.join(cacheDir.path, _chromeDefaultPath));
       final Directory targetChromeDefault = _fileSystem.directory(_fileSystem.path.join(userDataDir.path, _chromeDefaultPath));
       try {
         if (sourceChromeDefault.existsSync()) {
  
positive.code: /// A launcher for Chromium browsers with devtools configured.
  class ChromiumLauncher {
    ChromiumLauncher({
      @required FileSystem fileSystem,
      @required Platform platform,
      @required ProcessManager processManager,
      @required OperatingSystemUtils operatingSystemUtils,
      @required BrowserFinder browserFinder,
      @required Logger logger,
    }) : _fileSystem = fileSystem,
         _platform = platform,
         _processManager = processManager,
  
negative.code:     this.debugPort,
      this.chromeConnection, {
      this.url,
      Process? process,
      required ChromiumLauncher chromiumLauncher,
    })  : _process = process,
          _chromiumLauncher = chromiumLauncher;
  
    final String? url;
    final int debugPort;
    final Process? _process;
    final ChromeConnection chromeConnection;
    final ChromiumLauncher _chromiumLauncher;
  
    Future<int?> get onExit async => _process?.exitCode;
  
    Future<void> close() async {
      if (_chromiumLauncher.hasChromeInstance) {
  