Convert //ash from scoped_ptr to std::unique_ptr

ash/drag_drop/drag_image_view.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 ASH_DRAG_DROP_DRAG_IMAGE_VIEW_H_
 #define ASH_DRAG_DROP_DRAG_IMAGE_VIEW_H_
 
+#include <memory>
+
 #include "base/macros.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/views/controls/image_view.h"
 
 namespace gfx {
 class Image;
 }
 
 namespace views {
 class Widget;
@@ skipping 46 matching lines @@
 
  private:
   gfx::Image* DragHint() const;
 
   // Overridden from views::ImageView.
   void OnPaint(gfx::Canvas* canvas) override;
 
   // Overridden from views::view
   void Layout() override;
 
-  scoped_ptr<views::Widget> widget_;
+  std::unique_ptr<views::Widget> widget_;
   gfx::Size widget_size_;
 
   ui::DragDropTypes::DragEventSource drag_event_source_;
   int touch_drag_operation_;
   gfx::Point touch_drag_operation_indicator_position_;
 
   DISALLOW_COPY_AND_ASSIGN(DragImageView);
 };
 
 }  // namespace ash
 
 #endif  // ASH_DRAG_DROP_DRAG_IMAGE_VIEW_H_