Move package:testing to SDK.

pkg/testing/lib/src/error_handling.dart

Index: pkg/testing/lib/src/error_handling.dart
diff --git a/pkg/testing/lib/src/error_handling.dart b/pkg/testing/lib/src/error_handling.dart
new file mode 100644
index 0000000000000000000000000000000000000000..325afed58adc909fe92d36df6e8c4c4241245221
--- /dev/null
+++ b/pkg/testing/lib/src/error_handling.dart
@@ -0,0 +1,30 @@
+// Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE.md file.
+
+library testing.error_handling;
+
+import 'dart:async' show
+    Future;
+
+import 'dart:io' show
+    exitCode,
+    stderr;
+
+import 'dart:isolate' show
+    ReceivePort;
+
+Future withErrorHandling(Future f()) async {
+  final ReceivePort port = new ReceivePort();
+  try {
+    return await f();
+  } catch (e, trace) {
+    exitCode = 1;
+    stderr.writeln(e);
+    if (trace != null) {
+      stderr.writeln(trace);
+    }
+  } finally {
+    port.close();
+  }
+}