prepare for lint update of prefer_final_fields (#35059)
diff --git a/packages/flutter_tools/lib/src/devfs.dart b/packages/flutter_tools/lib/src/devfs.dart
index e15fb5c..7a28775 100644
--- a/packages/flutter_tools/lib/src/devfs.dart
+++ b/packages/flutter_tools/lib/src/devfs.dart
@@ -369,7 +369,7 @@
final _DevFSHttpWriter _httpWriter;
final String fsName;
final Directory rootDirectory;
- String _packagesFilePath;
+ final String _packagesFilePath;
final Set<String> assetPathsToEvict = <String>{};
List<Uri> sources = <Uri>[];
DateTime lastCompiled;