isolates refactor: this change introduces 'dart:isolate' as a library. This is a

tests/isolate/src/SerializationTest.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 serialization of messages without spawning
 // isolates.
 
 // ---------------------------------------------------------------------------
 // Serialization test.
 // ---------------------------------------------------------------------------
 #library('SerializationTest');
-#import("dart:coreimpl");
+#import('dart:isolate');
 
 main() {
-  testAllTypes(copy);
-  testAllTypes(serialize);
-}
-
-copy(x) {
-  return new Copier().traverse(x);
-}
-
-serialize(x) {
-  Serializer serializer = new Serializer();
-  Deserializer deserializer = new Deserializer();
-  return deserializer.deserialize(serializer.traverse(x));
+  testAllTypes(TestingOnly.copy);
+  testAllTypes(TestingOnly.serialize);
 }
 
 void testAllTypes(Function f) {
   copyAndVerify(0, f);
   copyAndVerify(499, f);
   copyAndVerify(true, f);
   copyAndVerify(false, f);
   copyAndVerify("", f);
   copyAndVerify("foo", f);
   copyAndVerify([], f);
@@ skipping 46 matching lines @@
     Expect.isTrue(copy is Map);
     Expect.equals(o.length, copy.length);
     o.forEach((key, value) {
       Expect.isTrue(copy.containsKey(key));
       verify(value, copy[key]);
     });
   } else {
     Expect.fail("Unexpected object encountered");
   }
 }