Convert //ash from scoped_ptr to std::unique_ptr

ash/metrics/task_switch_metrics_recorder.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/metrics/task_switch_metrics_recorder.h"
 
 #include "ash/metrics/task_switch_time_tracker.h"
+#include "base/memory/ptr_util.h"
 
 namespace ash {
 
 namespace {
 
 const char kAshTaskSwitchHistogramName[] = "Ash.TimeBetweenTaskSwitches";
 
 const char kDesktopHistogramName[] =
     "Ash.Desktop.TimeBetweenNavigateToTaskSwitches";
 
@@ skipping 71 matching lines @@
 
 void TaskSwitchMetricsRecorder::AddTaskSwitchTimeTracker(
     TaskSwitchSource task_switch_source) {
   CHECK(histogram_map_.find(task_switch_source) == histogram_map_.end());
 
   const char* histogram_name = GetHistogramName(task_switch_source);
   DCHECK(histogram_name);
 
   histogram_map_.add(
       task_switch_source,
-      make_scoped_ptr(new TaskSwitchTimeTracker(histogram_name)));
+      base::WrapUnique(new TaskSwitchTimeTracker(histogram_name)));
 }
 
 }  // namespace ash