Add a complex reload test that rebases the root script path three times.

runtime/observatory/tests/service/complex_reload/v1/main.dart

Index: runtime/observatory/tests/service/complex_reload/v1/main.dart
diff --git a/runtime/observatory/tests/service/complex_reload/v1/main.dart b/runtime/observatory/tests/service/complex_reload/v1/main.dart
new file mode 100644
index 0000000000000000000000000000000000000000..055565f0378df07b56abe23cd915b75ee05485ff
--- /dev/null
+++ b/runtime/observatory/tests/service/complex_reload/v1/main.dart
@@ -0,0 +1,14 @@
+// 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 file.
+// VMOptions=--error_on_bad_type --error_on_bad_override
+
+import 'dart:isolate';
+
+test() => 'apple';
+
+main() {
+  RawReceivePort keepAlive = new RawReceivePort();
+  print('slave isolate running');
+}
+