unittest step 3 and 4: remove TestFramework.dart, make test.dart use

tests/isolate/src/APIv2_spawnBrowserNegativeTest.dart

-// Copyright (c) 2012, 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.
-
-// Negative test to make sure that we are reaching all assertions.
-#library('spawn_tests');
-#import('../../../lib/unittest/unittest.dart');
-#import('../../../lib/unittest/dom_config.dart');
-#import('dart:dom'); // import added so test.dart can treat this as a webtest.
-#import('dart:isolate');
-
-child() {
-  port.receive((msg, reply) => reply.send('re: $msg'));
-}
-
-main() {
-  useDomConfiguration();
-  asyncTest('message - reply chain', 1, () {
-    ReceivePort port = new ReceivePort();
-    port.receive((msg, _) {
-      expect(msg).equals('re: hello'); // should be hi, not hello
-      port.close();
-      callbackDone();
-    });
-
-    SendPort s = spawnFunction(child);
-    s.send('hi', port.toSendPort());
-  });
-}