anchor.diff:      }
   
       List<String> addedPluginPaths = <String>[];
  -    for (String path in change.added) {
  -      FileState state = fileSystemState.getFileForPath(path);
  +    for (FileState state in driver.fsState.knownFiles) {
  +      String path = state.path;
         if (!isInRoot(path)) {
           // Found a file not in a previously known package.
           Uri uri = state.uri;
  
positive.code:   void addedDriver(AnalysisDriver driver, ContextRoot contextRoot) {
      _driverInfo[driver] = new _DriverInfo(
          contextRoot, <String>[contextRoot.root, _getSdkPath(driver)]);
      driver.fsState.knownFilesSetChanges.listen((KnownFilesSetChange change) {
        List<String> addedPluginPaths = _checkPluginsFor(driver, change);
        for (String pluginPath in addedPluginPaths) {
          manager.addPluginToContextRoot(contextRoot, pluginPath);
        }
  
negative.code:    * seen that defines a plugin. Return a list of the roots of all such plugins
     * that are found.
     */
    List<String> _checkPluginsFor(AnalysisDriver driver) {
      AbsolutePathContext context = resourceProvider.absolutePathContext;
      List<String> packageRoots = _driverInfo[driver].packageRoots;
  
      bool isInRoot(String path) {
        for (String root in packageRoots) {
  