Convert //ash from scoped_ptr to std::unique_ptr

ash/test/task_switch_time_tracker_test_api.h

Index: ash/test/task_switch_time_tracker_test_api.h
diff --git a/ash/test/task_switch_time_tracker_test_api.h b/ash/test/task_switch_time_tracker_test_api.h
index b45dfe093b95a95120321523c6bf522f8b6bdbda..c9a617eeaf4e048beb5932fda240e5074c15e579 100644
--- a/ash/test/task_switch_time_tracker_test_api.h
+++ b/ash/test/task_switch_time_tracker_test_api.h
@@ -5,10 +5,10 @@
 #ifndef ASH_TEST_TASK_SWITCH_TIME_TRACKER_TEST_API_H_
 #define ASH_TEST_TASK_SWITCH_TIME_TRACKER_TEST_API_H_
 
+#include <memory>
 #include <string>
 
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 
 namespace base {
@@ -43,7 +43,7 @@ class TaskSwitchTimeTrackerTestAPI {
   base::SimpleTestTickClock* tick_clock_;
 
   // The TaskSwitchTimeTracker to provide internal access to.
-  scoped_ptr<TaskSwitchTimeTracker> time_tracker_;
+  std::unique_ptr<TaskSwitchTimeTracker> time_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskSwitchTimeTrackerTestAPI);
 };