Add serialization support to the JS DataSender and DataReceiver.

device/serial/data_stream.mojom

 // 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.
 
 module device.serial {
 
 [Client=DataSourceClient]
 interface DataSource {
   // Initializes this DataSource with a data pipe handle to use for data
   // transmission.
@@ skipping 25 matching lines @@
   // Reports that the sink has successfully received |bytes_sent| bytes of data.
   ReportBytesSent(uint32 bytes_sent);
 
   // Reports that the sink has received |bytes_sent| bytes of data (possibly 0)
   // and encountered an error: |error|. The client should respond with
   // |bytes_to_flush|, the number of bytes enqueued in the data pipe but not yet
   // acked so the correct number of bytes can be flushed from the pipe.
   ReportBytesSentAndError(uint32 bytes_sent, int32 error) => (uint32 bytes_to_flush);
 };
 
+struct SerializedDataSender {

[raymes, 2014/09/17 02:05:04]

As noted I think it would be good to move these to a separate file because they
are more of an implementation detail of the client. 

Please also add some comments about what they are for.

[Sam McNally, 2014/09/17 08:07:14]

Done.

+  handle<message_pipe> sink;
+  handle<data_pipe_producer> data_pipe;
+  int32 fatal_error_value;
+  bool shut_down;
+};
+
+struct SerializedDataReceiver {
+  handle<message_pipe> source;
+  handle<data_pipe_consumer> data_pipe;
+  int32 fatal_error_value;
+  uint32 bytes_received;
+  bool paused;
+  bool shut_down;
+};
+
 }