Convert //ash from scoped_ptr to std::unique_ptr

ash/shelf/shelf_button_pressed_metric_tracker.h

 // Copyright 2015 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_SHELF_SHELF_BUTTON_PRESSED_METRIC_TRACKER_H_
 #define ASH_SHELF_SHELF_BUTTON_PRESSED_METRIC_TRACKER_H_
 
+#include <memory>
+
 #include "ash/ash_export.h"
 #include "ash/shelf/shelf_item_delegate.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/time/tick_clock.h"
 #include "base/time/time.h"
 #include "ui/events/event.h"
 
 namespace views {
 class Button;
 }  // namespace views
 
 namespace ash {
 
@@ skipping 45 matching lines @@
   bool IsSubsequentActivationEvent(const views::Button* sender) const;
 
   // Caches state data for a window minimized action. The |sender| is the button
   // that caused the action.
   void SetMinimizedData(const views::Button* sender);
 
   // Resets the state data associated with the last window minimize action.
   void ResetMinimizedData();
 
   // Time source for performed action times.
-  scoped_ptr<base::TickClock> tick_clock_;
+  std::unique_ptr<base::TickClock> tick_clock_;
 
   // Stores the time of the last window minimize action.
   base::TimeTicks time_of_last_minimize_;
 
   // Stores the source button of the last window minimize action.
   // NOTE: This may become stale and should not be operated on. Not owned.
   const views::Button* last_minimized_source_button_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfButtonPressedMetricTracker);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_BUTTON_PRESSED_METRIC_TRACKER_H_