Convert //ash from scoped_ptr to std::unique_ptr

ash/display/display_animator_chromeos.h

Index: ash/display/display_animator_chromeos.h
diff --git a/ash/display/display_animator_chromeos.h b/ash/display/display_animator_chromeos.h
index a4fc768ff9ca32f659e54401c850e2756916e753..a3e44ff88396141e7cc2400fc1f1cce912a775ab 100644
--- a/ash/display/display_animator_chromeos.h
+++ b/ash/display/display_animator_chromeos.h
@@ -6,6 +6,7 @@
 #define ASH_DISPLAY_DISPLAY_ANIMATOR_CHROMEOS_H_
 
 #include <map>
+#include <memory>
 
 #include "ash/ash_export.h"
 #include "ash/display/display_animator.h"
@@ -55,7 +56,7 @@ class ASH_EXPORT DisplayAnimatorChromeOS
   void ClearHidingLayers();
 
   std::map<aura::Window*, ui::Layer*> hiding_layers_;
-  scoped_ptr<base::OneShotTimer> timer_;
+  std::unique_ptr<base::OneShotTimer> timer_;
   base::WeakPtrFactory<DisplayAnimatorChromeOS> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DisplayAnimatorChromeOS);