Convert //ash from scoped_ptr to std::unique_ptr

ash/metrics/task_switch_time_tracker.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_time_tracker.h"
 
 #include "base/metrics/histogram.h"
 #include "base/time/default_tick_clock.h"
 
 namespace ash {
@@ skipping 14 matching lines @@
 
 }  // namespace
 
 TaskSwitchTimeTracker::TaskSwitchTimeTracker(const std::string& histogram_name)
     : histogram_name_(histogram_name),
       tick_clock_(new base::DefaultTickClock()) {
 }
 
 TaskSwitchTimeTracker::TaskSwitchTimeTracker(
     const std::string& histogram_name,
-    scoped_ptr<base::TickClock> tick_clock)
-    : histogram_name_(histogram_name), tick_clock_(tick_clock.release()) {
-}
+    std::unique_ptr<base::TickClock> tick_clock)
+    : histogram_name_(histogram_name), tick_clock_(tick_clock.release()) {}
 
 TaskSwitchTimeTracker::~TaskSwitchTimeTracker() {
 }
 
 void TaskSwitchTimeTracker::OnTaskSwitch() {
   if (!HasLastActionTime())
     SetLastActionTime();
   else
     RecordTimeDelta();
 }
@@ skipping 30 matching lines @@
   }
 
 #if DCHECK_IS_ON()
   histogram_->CheckName(histogram_name_);
 #endif  // DCHECK_IS_ON()
 
   return histogram_;
 }
 
 }  // namespace ash