Reland: Add code to deal with serial device disconnection detection on Windows

device/serial/serial_io_handler.h

 // 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.
 
 #ifndef DEVICE_SERIAL_SERIAL_IO_HANDLER_H_
 #define DEVICE_SERIAL_SERIAL_IO_HANDLER_H_
 
 #include "base/callback.h"
 #include "base/files/file.h"
 #include "base/memory/ref_counted.h"
@@ skipping 172 matching lines @@
 
   serial::SendError write_cancel_reason() const { return write_cancel_reason_; }
 
   bool write_canceled() const { return write_canceled_; }
 
   const serial::ConnectionOptions& options() const { return options_; }
 
   // Possibly fixes up a serial port path name in a platform-specific manner.
   static std::string MaybeFixUpPortName(const std::string& port_name);
 
+  base::SingleThreadTaskRunner* file_thread_task_runner() const {
+    return file_thread_task_runner_.get();
+  }
+
+  base::SingleThreadTaskRunner* ui_thread_task_runner() const {
+    return ui_thread_task_runner_.get();
+  }
+
+  const std::string& port() const { return port_; }
+
  private:
   friend class base::RefCounted<SerialIoHandler>;
 
   void MergeConnectionOptions(const serial::ConnectionOptions& options);
 
   // Continues an Open operation on the FILE thread.
   void StartOpen(const std::string& port,
                  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner);
 
   // Finalizes an Open operation (continued from StartOpen) on the IO thread.
@@ skipping 19 matching lines @@
   serial::SendError write_cancel_reason_;
   bool write_canceled_;
 
   // Callback to handle the completion of a pending Open() request.
   OpenCompleteCallback open_complete_;
 
   scoped_refptr<base::SingleThreadTaskRunner> file_thread_task_runner_;
   // On Chrome OS, PermissionBrokerClient should be called on the UI thread.
   scoped_refptr<base::SingleThreadTaskRunner> ui_thread_task_runner_;
 
+  std::string port_;
+
   DISALLOW_COPY_AND_ASSIGN(SerialIoHandler);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_SERIAL_SERIAL_IO_HANDLER_H_