Dart: Encode/Decode handle and interface types.

mojo/public/dart/src/interface.dart

 // Copyright 2014 The Chromium Authors. 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 bindings;
 
 abstract class Interface extends core.MojoEventStreamListener {
   int _outstandingResponseFutures = 0;
   bool _isClosing = false;
 
   Interface(core.MojoMessagePipeEndpoint endpoint) : super(endpoint);
 
-  Interface.fromHandle(int handle) : super.fromHandle(handle);
+  Interface.fromHandle(core.MojoHandle handle) : super.fromHandle(handle);
+
+  Interface.unbound() : super.unbound();
 
   Future<Message> handleMessage(ServiceMessage message);
 
   void handleRead() {
     // Query how many bytes are available.
     var result = endpoint.query();
     assert(result.status.isOk || result.status.isResourceExhausted);
 
     // Read the data and view as a message.
     var bytes = new ByteData(result.bytesRead);
@@ skipping 60 matching lines @@
     return response.serializeWithHeader(header);
   }
 
   void sendMessage(Struct message, int name) {
     var header = new MessageHeader(name);
     var serviceMessage = message.serializeWithHeader(header);
     endpoint.write(serviceMessage.buffer,
                     serviceMessage.buffer.lengthInBytes,
                     serviceMessage.handles);
     if (!endpoint.status.isOk) {
-      throw "message pipe write failed";
+      throw "message pipe write failed: ${endpoint.status}";
     }
   }
 
   Future sendMessageWithRequestId(Struct response, int name, int id) {
     throw "The client interface should not expect a response";
   }
 }