Update {virtual,override} to follow C++11 style in device.

device/serial/serial_io_handler_win.h

Index: device/serial/serial_io_handler_win.h
diff --git a/device/serial/serial_io_handler_win.h b/device/serial/serial_io_handler_win.h
index 6cdbedc0dee041c5399df12fb0b4b0a3e4afc69d..838fdc87a776fbb4d60eab64a1b96121daf13cfd 100644
--- a/device/serial/serial_io_handler_win.h
+++ b/device/serial/serial_io_handler_win.h
@@ -15,17 +15,17 @@ class SerialIoHandlerWin : public SerialIoHandler,
                            public base::MessageLoopForIO::IOHandler {
  protected:
   // SerialIoHandler implementation.
-  virtual void ReadImpl() override;
-  virtual void WriteImpl() override;
-  virtual void CancelReadImpl() override;
-  virtual void CancelWriteImpl() override;
-  virtual bool ConfigurePortImpl() override;
-  virtual bool Flush() const override;
-  virtual serial::DeviceControlSignalsPtr GetControlSignals() const override;
-  virtual bool SetControlSignals(
+  void ReadImpl() override;
+  void WriteImpl() override;
+  void CancelReadImpl() override;
+  void CancelWriteImpl() override;
+  bool ConfigurePortImpl() override;
+  bool Flush() const override;
+  serial::DeviceControlSignalsPtr GetControlSignals() const override;
+  bool SetControlSignals(
       const serial::HostControlSignals& control_signals) override;
-  virtual serial::ConnectionInfoPtr GetPortInfo() const override;
-  virtual bool PostOpen() override;
+  serial::ConnectionInfoPtr GetPortInfo() const override;
+  bool PostOpen() override;
 
  private:
   friend class SerialIoHandler;
@@ -33,12 +33,12 @@ class SerialIoHandlerWin : public SerialIoHandler,
   explicit SerialIoHandlerWin(
       scoped_refptr<base::MessageLoopProxy> file_thread_message_loop,
       scoped_refptr<base::MessageLoopProxy> ui_thread_message_loop);
-  virtual ~SerialIoHandlerWin();
+  ~SerialIoHandlerWin() override;
 
   // base::MessageLoopForIO::IOHandler implementation.
-  virtual void OnIOCompleted(base::MessageLoopForIO::IOContext* context,
-                             DWORD bytes_transfered,
-                             DWORD error) override;
+  void OnIOCompleted(base::MessageLoopForIO::IOContext* context,
+                     DWORD bytes_transfered,
+                     DWORD error) override;
 
   // Context used for asynchronous WaitCommEvent calls.
   scoped_ptr<base::MessageLoopForIO::IOContext> comm_context_;