Convert //ash from scoped_ptr to std::unique_ptr

ash/first_run/desktop_cleaner.h

Index: ash/first_run/desktop_cleaner.h
diff --git a/ash/first_run/desktop_cleaner.h b/ash/first_run/desktop_cleaner.h
index 63d0f3856ff1b387e3b02842c8f80e4d1e80fdee..fe762825de2aaa9aa34b1430ea4d1a6189a7f7b6 100644
--- a/ash/first_run/desktop_cleaner.h
+++ b/ash/first_run/desktop_cleaner.h
@@ -5,12 +5,12 @@
 #ifndef ASH_FIRST_RUN_DESKTOP_CLEANER_
 #define ASH_FIRST_RUN_DESKTOP_CLEANER_
 
+#include <memory>
 #include <vector>
 
 #include "ash/ash_export.h"
 #include "base/macros.h"
 #include "base/memory/linked_ptr.h"
-#include "base/memory/scoped_ptr.h"
 
 namespace ash {
 class ContainerHider;
@@ -31,7 +31,7 @@ class ASH_EXPORT DesktopCleaner {
   static std::vector<int> GetContainersToHideForTest();
 
   std::vector<linked_ptr<ContainerHider> > container_hiders_;
-  scoped_ptr<NotificationBlocker> notification_blocker_;
+  std::unique_ptr<NotificationBlocker> notification_blocker_;
 
   friend class ash::test::FirstRunHelperTest;
   DISALLOW_COPY_AND_ASSIGN(DesktopCleaner);