Delete dart2js specific private library code

tool/input_sdk/private/isolate_serialization.dart

 // Copyright (c) 2014, 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.
 
 part of _isolate_helper;
 
 /// Serialize [message].
 _serializeMessage(message) {
   return new _Serializer().serialize(message);
 }
@@ skipping 42 matching lines @@
 
     if (x is RawReceivePort) {
       unsupported(x, "RawReceivePorts can't be transmitted:");
     }
 
     // SendPorts need their workerIds adjusted (either during serialization or
     // deserialization).
     if (x is _NativeJsSendPort) return serializeJsSendPort(x);
     if (x is _WorkerSendPort) return serializeWorkerSendPort(x);
 
-    if (x is Closure) return serializeClosure(x);
+    if (x is Function) return serializeClosure(x);
 
     return serializeDartObject(x);
   }
 
   void unsupported(x, [String message]) {
     if (message == null) message = "Can't transmit:";
     throw new UnsupportedError("$message $x");
   }
 
   makeRef(int serializationId) => ["ref", serializationId];
@@ skipping 75 matching lines @@
   serializeJsSendPort(_NativeJsSendPort x) {
     if (_serializeSendPorts) {
       int workerId = _globalState.currentManagerId;
       return ['sendport', workerId, x._isolateId, x._receivePort._id];
     }
     return ['raw sendport', x];
   }
 
   serializeCapability(CapabilityImpl x) => ['capability', x._id];
 
-  serializeClosure(Closure x) {
+  serializeClosure(Function x) {
     final name = IsolateNatives._getJSFunctionName(x);
     if (name == null) {
       unsupported(x, "Closures can't be transmitted:");
     }
     return ['function', name];
   }
 
   serializeDartObject(x) {
     var classExtractor = JS_EMBEDDED_GLOBAL('', CLASS_ID_EXTRACTOR);
     var fieldsExtractor = JS_EMBEDDED_GLOBAL('', CLASS_FIELDS_EXTRACTOR);
@@ skipping 182 matching lines @@
     var instanceFromClassId = JS_EMBEDDED_GLOBAL('', INSTANCE_FROM_CLASS_ID);
     var initializeObject = JS_EMBEDDED_GLOBAL('', INITIALIZE_EMPTY_INSTANCE);
 
     var emptyInstance = JS('', '#(#)', instanceFromClassId, classId);
     deserializedObjects.add(emptyInstance);
     deserializeArrayInPlace(fields);
     return JS('', '#(#, #, #)',
               initializeObject, classId, emptyInstance, fields);
   }
 }