Add RuntimeError to default expectations and handle expectation groups correctly.

pkg/testing/lib/src/chain.dart

Index: pkg/testing/lib/src/chain.dart
diff --git a/pkg/testing/lib/src/chain.dart b/pkg/testing/lib/src/chain.dart
index d51fdb27302ebeba96023adc4ec0adbad2c895a2..022db73b84662e1eb2e45bab0708e76c15fa0e2b 100644
--- a/pkg/testing/lib/src/chain.dart
+++ b/pkg/testing/lib/src/chain.dart
@@ -205,7 +205,8 @@ abstract class ChainContext {
             }
             result = toNegativeTestResult(result);
           }
-          if (!expectedOutcomes.contains(result.outcome)) {
+          if (!expectedOutcomes.contains(result.outcome) &&
+              !expectedOutcomes.contains(result.outcome.canonical)) {
             result.addLog("$sb");
             unexpectedResults[description] = result;
             unexpectedOutcomes[description] = expectedOutcomes;