Use dartfmt on Observatory code

runtime/observatory/web/main.dart

Index: runtime/observatory/web/main.dart
diff --git a/runtime/observatory/web/main.dart b/runtime/observatory/web/main.dart
index b69f66ebf1cd5dde0296e77574658b44b8ba3391..07fcb1a635fc3c256cba28df88a208a18b9b5a18 100644
--- a/runtime/observatory/web/main.dart
+++ b/runtime/observatory/web/main.dart
@@ -11,7 +11,7 @@ main() async {
   Chain.capture(() async {
     Logger.root.level = Level.INFO;
     Logger.root.onRecord.listen((LogRecord rec) {
-        print('${rec.level.name}: ${rec.time}: ${rec.message}');
+      print('${rec.level.name}: ${rec.time}: ${rec.message}');
     });
     await initElements();
     Logger.root.info('Starting Observatory');