Standardize usage of virtual/override/final specifiers in device/.

device/serial/data_sender.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_DATA_SENDER_H_
 #define DEVICE_SERIAL_DATA_SENDER_H_
 
 #include <queue>
 
 #include "base/callback.h"
@@ skipping 12 matching lines @@
   typedef base::Callback<void(uint32_t bytes_sent, int32_t error)>
       SendErrorCallback;
   typedef base::Callback<void()> CancelCallback;
 
   // Constructs a DataSender to send data to |sink|, using a buffer size of
   // |buffer_size|, with connection errors reported as |fatal_error_value|.
   DataSender(mojo::InterfacePtr<serial::DataSink> sink,
              uint32_t buffer_size,
              int32_t fatal_error_value);
 
-  ~DataSender();
+  ~DataSender() override;
 
   // Starts an asynchronous send of |data|. If the send completes successfully,
   // |callback| will be called. Otherwise, |error_callback| will be called with
   // the error. If there is a cancel in progress or there has been a connection
   // error, this will not start a send and returns false. It is the caller's
   // responsibility to ensure |data| remains valid until one of |callback| and
   // |error_callback| is called.
   bool Send(const base::StringPiece& data,
             const DataSentCallback& callback,
             const SendErrorCallback& error_callback);
@@ skipping 49 matching lines @@
 
   // Whether we have encountered a fatal error and shut down.
   bool shut_down_;
 
   DISALLOW_COPY_AND_ASSIGN(DataSender);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_SERIAL_DATA_SENDER_H_