anchor.diff:  
          return Future.forEach(entries, (chrome.Entry entry) {
            if (entry.name == '.git') {
  -           return new Future.value();
  +           return filePaths;
            }
   
            if (entry.isDirectory) {
  -           return walkFilesAndUpdateIndex(entry as chrome.DirectoryEntry).then((String sha) {
  -             return new Future.value();
  +           return walkFilesAndUpdateIndex(entry as chrome.DirectoryEntry)
  +               .then((List<String> paths) {
  +             filePaths.addAll(paths);
  +             return filePaths;
              });
            } else {
              // don't update index for untracked files.
  
positive.code: 
    Index(this._store);
  
    void deleteIndexForEntry(FileStatus status) {
      if (_statusIdx.containsKey(status.path)) {
        _statusIdx.remove(status.path);
      }
    }
  
  
negative.code:            }
           }
        }).then((_) {
           return filePaths;
         });
      });
    }
  
  