test rename overhaul: step 6 - isolate tests

tests/isolate/mixed_test.dart

 // Copyright (c) 2011, 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.
 
 // Dart test program for testing that heavy and light isolates can be mixed.
 
 #library('MixedTest');
 #import("dart:isolate");
-#import('../../../lib/unittest/unittest.dart');
+#import('../../lib/unittest/unittest.dart');
 
 class IsolateA extends Isolate {
   IsolateA() : super.heavy();
 
   void main() {
     this.port.receive((msg, replyTo) {
       Expect.equals("launch nested!", msg);
       new IsolateB().spawn().then((SendPort p) {
         p.call("alive?").then((msg) {
           Expect.equals("and kicking", msg);
@@ skipping 19 matching lines @@
 
 main() {
   test("light isolate can spawn heavy isolate", () {
     new IsolateA().spawn().then(expectAsync1((SendPort port) {
       port.call("launch nested!").then(expectAsync1((msg) {
         Expect.equals(499, msg);
       }));
     }));
   });
 }