Convert //ash from scoped_ptr to std::unique_ptr

ash/display/mouse_cursor_event_filter.h

Index: ash/display/mouse_cursor_event_filter.h
diff --git a/ash/display/mouse_cursor_event_filter.h b/ash/display/mouse_cursor_event_filter.h
index 85b097e8ef6d5245e5cbf99eea6f20ff7361b3eb..9da9a41125ab5e0c65c7805918d99012790e89ca 100644
--- a/ash/display/mouse_cursor_event_filter.h
+++ b/ash/display/mouse_cursor_event_filter.h
@@ -5,12 +5,13 @@
 #ifndef ASH_DISPLAY_MOUSE_CURSOR_EVENT_FILTER_H
 #define ASH_DISPLAY_MOUSE_CURSOR_EVENT_FILTER_H
 
+#include <memory>
+
 #include "ash/ash_export.h"
 #include "ash/display/window_tree_host_manager.h"
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "ui/events/event_handler.h"
 #include "ui/gfx/geometry/rect.h"
 
@@ -62,7 +63,7 @@ class ASH_EXPORT MouseCursorEventFilter
 
   bool mouse_warp_enabled_;
 
-  scoped_ptr<MouseWarpController> mouse_warp_controller_;
+  std::unique_ptr<MouseWarpController> mouse_warp_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(MouseCursorEventFilter);
 };