Add a partial Mojo serial connection interface and implementation.

device/serial/serial.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 {
 
 struct DeviceInfo {
   string path;
   uint16 vendor_id;
   bool has_vendor_id = false;
@@ skipping 63 matching lines @@
 
 struct DeviceControlSignals {
   bool dcd;
   bool cts;
   bool ri;
   bool dsr;
 };
 
 interface SerialService {
   GetDevices() => (DeviceInfo[] devices);
+  Connect(string path,
+          ConnectionOptions options,
+          Connection& connection_request);

[darin (slow to review), 2014/07/18 04:46:15]

nit: stylistically, i think it is OK to call this parameter just "connection".
you could think of it as you are connecting the connection object to the serial
service.

[Sam McNally, 2014/07/21 03:25:37]

Done.

+};
+
+interface Connection {
+  GetInfo() => (ConnectionInfo info);
+  SetOptions(ConnectionOptions options) => (bool success);
+  SetControlSignals(HostControlSignals signals) => (bool success);
+  GetControlSignals() => (DeviceControlSignals signals);
+  Flush() => (bool success);
 };
 
 }