Convert //ash from scoped_ptr to std::unique_ptr

ash/accelerators/magnifier_key_scroller.h

Index: ash/accelerators/magnifier_key_scroller.h
diff --git a/ash/accelerators/magnifier_key_scroller.h b/ash/accelerators/magnifier_key_scroller.h
index 40fbd9eac6c0723acf600063f53c7776e457d1f4..eeea84b502c87444f7733230f16cfb00404bdc93 100644
--- a/ash/accelerators/magnifier_key_scroller.h
+++ b/ash/accelerators/magnifier_key_scroller.h
@@ -5,10 +5,11 @@
 #ifndef ASH_ACCELERATORS_MAGNIFIER_KEY_SCROLLER_H_
 #define ASH_ACCELERATORS_MAGNIFIER_KEY_SCROLLER_H_
 
+#include <memory>
+
 #include "ash/accelerators/key_hold_detector.h"
 #include "ash/ash_export.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "ui/events/event_handler.h"
 
 namespace ui {
@@ -22,7 +23,7 @@ class ASH_EXPORT MagnifierKeyScroller : public KeyHoldDetector::Delegate {
  public:
   static bool IsEnabled();
   static void SetEnabled(bool enabled);
-  static scoped_ptr<ui::EventHandler> CreateHandler();
+  static std::unique_ptr<ui::EventHandler> CreateHandler();
 
   // A scoped object to enable and disable the magnifier accelerator for test.
   class ScopedEnablerForTest {