Reland: use flutter features for web and desktop (#36699)


diff --git a/dev/bots/test.dart b/dev/bots/test.dart
index f103674..48be0bb 100644
--- a/dev/bots/test.dart
+++ b/dev/bots/test.dart
@@ -289,6 +289,9 @@
     workingDirectory: path.join(flutterRoot, relativePathToApplication),
     expectNonZeroExit: false,
     timeout: _kShortTimeout,
+    environment: <String, String>{
+      'FLUTTER_WEB': 'true',
+    }
   );
   print('Done.');
 }