Don't run stack_trace tests on Dartium.

pkg/pkg.status

Index: pkg/pkg.status
diff --git a/pkg/pkg.status b/pkg/pkg.status
index e96bd26a673a52c3e8363ce8119864ae15116ed0..0affdd6b25b5efed0472715383086138a869248f 100644
--- a/pkg/pkg.status
+++ b/pkg/pkg.status
@@ -66,6 +66,10 @@ analyzer_experimental/test/generated/scanner_test: Skip # Imports dart:io.
 # otherwise be dart2js-compatible.
 scheduled_test/test/*: Skip
 
+# We use pathos in the stack_trace tests. We can run them on dart2js when issue
+# 6943 is fixed.
+stack_trace/test/*: Skip
+
 [ $runtime == opera && $compiler == dart2js ]
 intl/test/find_default_locale_browser_test: Fail
 intl/test/date_time_format_http_request_test: Skip # Timeout.