Use sky_shell instead of mojo_shell for testing.

sky/tests/resources/unit.dart

-
-import "dart:sky.internals" as internals;
-
-import 'package:sky/mojo/shell.dart' as shell;
-import 'package:mojom/sky/test_harness.mojom.dart';
-
 import "third_party/unittest/unittest.dart";
-
-void notifyTestComplete(String result) {
-  TestHarnessProxy test_harness = new TestHarnessProxy.unbound();
-  shell.requestService("mojo:sky_viewer", test_harness);
-  test_harness.ptr.onTestComplete(result, null);
-  test_harness.close();
-
-  internals.notifyTestComplete("DONE");
-}
+import "harness.dart";
 
 class _SkyConfig extends SimpleConfiguration {
   void onDone(bool success) {
     try {
       super.onDone(success);
     } catch (ex) {
       print(ex.toString());
     }
 
     notifyTestComplete("DONE");
   }
 }
 
 final _singleton = new _SkyConfig();
 
 void initUnit() {
   unittestConfiguration = _singleton;
 }