Update {virtual,override,final} to follow C++11 style in chrome/browser/chromeos/drive.

chrome/browser/chromeos/drive/fake_free_disk_space_getter.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_DRIVE_FAKE_FREE_DISK_SPACE_GETTER_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_FAKE_FREE_DISK_SPACE_GETTER_H_
 
 #include <list>
 
 #include "base/basictypes.h"
 #include "chrome/browser/chromeos/drive/file_cache.h"
 
 namespace drive {
 
 // This class is used to report fake free disk space. In particular, this
 // class can be used to simulate a case where disk is full, or nearly full.
 class FakeFreeDiskSpaceGetter : public internal::FreeDiskSpaceGetterInterface {
  public:
   FakeFreeDiskSpaceGetter();
-  virtual ~FakeFreeDiskSpaceGetter();
+  ~FakeFreeDiskSpaceGetter() override;
 
   void set_default_value(int64 value) { default_value_ = value; }
 
   // Pushes the given value to the back of the fake value list.
   //
   // If the fake value list is empty, AmountOfFreeDiskSpace() will return
   // |default_value_| repeatedly.
   // Otherwise, AmountOfFreeDiskSpace() will return the value at the front of
   // the list and removes it from the list.
   void PushFakeValue(int64 value);
 
   // FreeDiskSpaceGetterInterface overrides.
-  virtual int64 AmountOfFreeDiskSpace() override;
+  int64 AmountOfFreeDiskSpace() override;
 
  private:
   std::list<int64> fake_values_;
   int64 default_value_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeFreeDiskSpaceGetter);
 };
 
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FAKE_FREE_DISK_SPACE_GETTER_H_