Convert //ash from scoped_ptr to std::unique_ptr

ash/rotator/screen_rotation_animation.h

Index: ash/rotator/screen_rotation_animation.h
diff --git a/ash/rotator/screen_rotation_animation.h b/ash/rotator/screen_rotation_animation.h
index e93f6f6f53c7f27da47006a820afd9e5560fba9c..66e0df97d6e90f4dfc188aa9115cb8cacc4eb3d9 100644
--- a/ash/rotator/screen_rotation_animation.h
+++ b/ash/rotator/screen_rotation_animation.h
@@ -7,9 +7,10 @@
 
 #include <stdint.h>
 
+#include <memory>
+
 #include "ash/ash_export.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "ui/compositor/layer_animation_element.h"
 #include "ui/gfx/animation/tween.h"
@@ -48,7 +49,7 @@ class ASH_EXPORT ScreenRotationAnimation : public ui::LayerAnimationElement {
   void OnAbort(ui::LayerAnimationDelegate* delegate) override;
 
   // The root InterpolatedTransform that defines the animation.
-  scoped_ptr<ui::InterpolatedTransform> interpolated_transform_;
+  std::unique_ptr<ui::InterpolatedTransform> interpolated_transform_;
 
   // The Tween type to use for the animation.
   gfx::Tween::Type tween_type_;