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

printing/backend/print_backend_win.cc

 // Copyright (c) 2012 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.
 
 #include "printing/backend/print_backend.h"
 
 #include <objidl.h>
 #include <winspool.h>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 139 matching lines @@
   }
 }
 
 }  // namespace
 
 class PrintBackendWin : public PrintBackend {
  public:
   PrintBackendWin() {}
 
   // PrintBackend implementation.
-  virtual bool EnumeratePrinters(PrinterList* printer_list) override;
-  virtual std::string GetDefaultPrinterName() override;
-  virtual bool GetPrinterSemanticCapsAndDefaults(
+  bool EnumeratePrinters(PrinterList* printer_list) override;
+  std::string GetDefaultPrinterName() override;
+  bool GetPrinterSemanticCapsAndDefaults(
       const std::string& printer_name,
       PrinterSemanticCapsAndDefaults* printer_info) override;
-  virtual bool GetPrinterCapsAndDefaults(
+  bool GetPrinterCapsAndDefaults(
       const std::string& printer_name,
       PrinterCapsAndDefaults* printer_info) override;
-  virtual std::string GetPrinterDriverInfo(
+  std::string GetPrinterDriverInfo(
       const std::string& printer_name) override;
-  virtual bool IsValidPrinter(const std::string& printer_name) override;
+  bool IsValidPrinter(const std::string& printer_name) override;
 
  protected:
-  virtual ~PrintBackendWin() {}
+  ~PrintBackendWin() override {}
 };
 
 bool PrintBackendWin::EnumeratePrinters(PrinterList* printer_list) {
   DCHECK(printer_list);
   DWORD bytes_needed = 0;
   DWORD count_returned = 0;
   const DWORD kLevel = 4;
   BOOL ret = EnumPrinters(PRINTER_ENUM_LOCAL|PRINTER_ENUM_CONNECTIONS, NULL,
                           kLevel, NULL, 0, &bytes_needed, &count_returned);
   if (!bytes_needed)
@@ skipping 176 matching lines @@
   ScopedPrinterHandle printer_handle;
   return printer_handle.OpenPrinter(base::UTF8ToWide(printer_name).c_str());
 }
 
 scoped_refptr<PrintBackend> PrintBackend::CreateInstance(
     const base::DictionaryValue* print_backend_settings) {
   return new PrintBackendWin;
 }
 
 }  // namespace printing