Test is an old workaround is still necessary
diff --git a/pkgs/test/tool/host.dart b/pkgs/test/tool/host.dart
index 23d83ae..d6bb00e 100644
--- a/pkgs/test/tool/host.dart
+++ b/pkgs/test/tool/host.dart
@@ -237,13 +237,8 @@
// This message indicates that the iframe is actively listening for
// events, so the message channel's second port can now be transferred.
channel.port2.start();
- // TODO(#1758): This is a work around for a crash in package:build.
- js_util.callMethod(
- js_util.getProperty(iframe, 'contentWindow'), 'postMessage', [
- 'port',
- dom.window.location.origin,
- [channel.port2]
- ]);
+ iframe.contentWindow
+ .postMessage('port', dom.window.location.origin, [channel.port2]);
readyCompleter.complete();
} else if (message.data['exception'] == true) {
// This message from `dart.js` indicates that an exception occurred
