Add serialization support to the JS DataSender and DataReceiver.

device/serial/data_stream.mojom

Index: device/serial/data_stream.mojom
diff --git a/device/serial/data_stream.mojom b/device/serial/data_stream.mojom
index 689b38148411ede1b7ca63c39c3a2f47a841027b..6e831dd9590491b35844c1f0c40296cc67019e02 100644
--- a/device/serial/data_stream.mojom
+++ b/device/serial/data_stream.mojom
@@ -43,4 +43,20 @@ interface DataSinkClient {
   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;
+};
+
 }