Changes to how we handle fancy stacks:

pkg/unittest/lib/html_config.dart

Index: pkg/unittest/lib/html_config.dart
===================================================================
--- pkg/unittest/lib/html_config.dart	(revision 26539)
+++ pkg/unittest/lib/html_config.dart	(working copy)
@@ -132,6 +132,11 @@
   }
 
   void onInit() {
+    // For Dart internal tests, we want to turn off stack frame
+    // filtering, which we do with this meta-header.
+    var meta = query('meta[name="dart.unittest"]');
+    filterStacks = meta == null ? true :
+       !meta.content.contains('full-stack-traces');
     _installHandlers();
     window.postMessage('unittest-suite-wait-for-done', '*');
   }