Convert //chrome/browser/chromeos from scoped_ptr to std::unique_ptr

chrome/browser/chromeos/login/easy_unlock/easy_unlock_reauth.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 CHROME_BROWSER_CHROMEOS_LOGIN_EASY_UNLOCK_EASY_UNLOCK_REAUTH_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_EASY_UNLOCK_EASY_UNLOCK_REAUTH_H_
 
+#include <memory>
+
 #include "base/callback_forward.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 
 namespace chromeos {
 
 class UserContext;
 
 // Responsible for locking the screen and reauthenticating the user so we can
 // create new cryptohome keys for passwordless sign-in.
 class EasyUnlockReauth {
  public:
   typedef base::Callback<void(const UserContext&)> UserContextCallback;
 
   // Launches the reauth screen to get the user context. If the screen fails
   // for some reason, then this function will return false.
   static bool ReauthForUserContext(UserContextCallback callback);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(EasyUnlockReauth);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_EASY_UNLOCK_EASY_UNLOCK_REAUTH_H_