isolates: remove Isolate2 interface, add top-level spawn functions, more comments

tests/isolate/src/APIv2_spawnBrowserTest.dart

Index: tests/isolate/src/APIv2_spawnBrowserTest.dart
diff --git a/tests/isolate/src/APIv2_spawnBrowserTest.dart b/tests/isolate/src/APIv2_spawnBrowserTest.dart
index 34960b894392cc452ad77ffe296706cecca62ead..45e4f2bfbd9c637af1ee129a42fb98fe2b7659fe 100644
--- a/tests/isolate/src/APIv2_spawnBrowserTest.dart
+++ b/tests/isolate/src/APIv2_spawnBrowserTest.dart
@@ -2,26 +2,26 @@
 // 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.
 
-// example of spawning an isolate from a closure
+// Example of spawning an isolate from a function.
 #library('spawn_tests');
-#import("../../../client/testing/unittest/unittest.dart");
-#import("dart:dom"); // import added so test.dart can treat this as a webtest.
+#import('../../../client/testing/unittest/unittest.dart');
+#import('dart:dom'); // import added so test.dart can treat this as a webtest.
 #import('dart:isolate');
 
-child(ReceivePort port) {
-  port.receive((msg, reply) => reply.send("re: $msg"));
+child() {
+  port.receive((msg, reply) => reply.send('re: $msg'));
 }
 
 main() {
-  asyncTest("message - reply chain", 1, () {
+  asyncTest('message - reply chain', 1, () {
     ReceivePort port = new ReceivePort();
     port.receive((msg, _) {
-      expect(msg).equals("re: hi");
+      expect(msg).equals('re: hi');
       port.close();
       callbackDone();
     });
 
-    Isolate2 c = new Isolate2.fromCode(child);
-    c.sendPort.send("hi", port.toSendPort());
+    SendPort s = spawnFunction(child);
+    s.send('hi', port.toSendPort());
   });
 }