Fix for issue 21398 (only send "literal like" objects across isolates spawned using spawnURI

runtime/lib/isolate_patch.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.
 
 import "dart:collection" show HashMap;
 import "dart:_internal";
 
 patch class ReceivePort {
   /* patch */ factory ReceivePort() = _ReceivePortImpl;
 
@@ skipping 324 matching lines @@
 
   // TODO(iposva): Cleanup to have only one definition.
   // These values need to be kept in sync with the class IsolateMessageHandler
   // in vm/isolate.cc.
   static const _PAUSE = 1;
   static const _RESUME = 2;
   static const _PING = 3;
   static const _KILL = 4;
 
 
-  static SendPort _spawnFunction(SendPort readyPort, Function topLevelFunction,
-                                 var message, bool paused)
+  static void _spawnFunction(SendPort readyPort, Function topLevelFunction,
+                             var message, bool paused)
       native "Isolate_spawnFunction";
 
-  static SendPort _spawnUri(SendPort readyPort, String uri,
-                            List<String> args, var message,
-                            bool paused, String packageRoot)
+  static void _spawnUri(SendPort readyPort, String uri,
+                        List<String> args, var message,
+                        bool paused, String packageRoot)
       native "Isolate_spawnUri";
 
   static void _sendOOB(port, msg) native "Isolate_sendOOB";
 
   /* patch */ void _pause(Capability resumeCapability) {
     var msg = new List(4)
         ..[0] = 0  // Make room for OOB message type.
         ..[1] = _PAUSE
         ..[2] = pauseCapability
         ..[3] = resumeCapability;
@@ skipping 50 matching lines @@
   static Isolate _getCurrentIsolate() {
     List portAndCapabilities = _getPortAndCapabilitiesOfCurrentIsolate();
     return new Isolate(portAndCapabilities[0],
                        pauseCapability: portAndCapabilities[1],
                        terminateCapability: portAndCapabilities[2]);
   }
 
   static List _getPortAndCapabilitiesOfCurrentIsolate()
       native "Isolate_getPortAndCapabilitiesOfCurrentIsolate";
 }