Convert //ash from scoped_ptr to std::unique_ptr

ash/wm/overview/window_selector_item.h

Index: ash/wm/overview/window_selector_item.h
diff --git a/ash/wm/overview/window_selector_item.h b/ash/wm/overview/window_selector_item.h
index 36ab26dbe50bebce232b5be8c0ee3d8c87f250c9..2ae09928ba8b5b9bd16664a7c2acfd78b2a5c378 100644
--- a/ash/wm/overview/window_selector_item.h
+++ b/ash/wm/overview/window_selector_item.h
@@ -5,11 +5,12 @@
 #ifndef ASH_WM_OVERVIEW_WINDOW_SELECTOR_ITEM_H_
 #define ASH_WM_OVERVIEW_WINDOW_SELECTOR_ITEM_H_
 
+#include <memory>
+
 #include "ash/ash_export.h"
 #include "ash/wm/overview/scoped_transform_overview_window.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "ui/aura/scoped_window_targeter.h"
 #include "ui/aura/window_observer.h"
 #include "ui/gfx/geometry/rect.h"
@@ -150,7 +151,7 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
   bool in_bounds_update_;
 
   // Label under the window displaying its active tab name.
-  scoped_ptr<views::Widget> window_label_;
+  std::unique_ptr<views::Widget> window_label_;
 
   // View for the label under the window.
   OverviewLabelButton* window_label_button_view_;