Convert //ash from scoped_ptr to std::unique_ptr

ash/system/chromeos/session/tray_session_length_limit.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 ASH_SYSTEM_CHROMEOS_SESSION_SESSION_LENGTH_LIMIT_H_
 #define ASH_SYSTEM_CHROMEOS_SESSION_SESSION_LENGTH_LIMIT_H_
 
+#include <memory>
+
 #include "ash/system/chromeos/session/session_length_limit_observer.h"
 #include "ash/system/tray/system_tray_item.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 
 namespace ash {
 namespace test {
 class TraySessionLengthLimitTest;
 }
 
 class LabelTrayView;
@@ skipping 39 matching lines @@
   base::string16 ComposeTrayBubbleMessage() const;
 
   base::TimeTicks session_start_time_;
   base::TimeDelta time_limit_;
   base::TimeDelta remaining_session_time_;
 
   LimitState limit_state_;       // Current state.
   LimitState last_limit_state_;  // State of last notification update.
 
   LabelTrayView* tray_bubble_view_;
-  scoped_ptr<base::RepeatingTimer> timer_;
+  std::unique_ptr<base::RepeatingTimer> timer_;
 
   DISALLOW_COPY_AND_ASSIGN(TraySessionLengthLimit);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_CHROMEOS_SESSION_SESSION_LENGTH_LIMIT_H_