Replace unique_ptr.reset(other_unique_ptr.release()) with std::move() in ash/

ash/test/shelf_button_pressed_metric_tracker_test_api.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/test/shelf_button_pressed_metric_tracker_test_api.h"
 
 #include "base/time/tick_clock.h"
 
 namespace ash {
 namespace test {
 
 ShelfButtonPressedMetricTrackerTestAPI::ShelfButtonPressedMetricTrackerTestAPI(
     ShelfButtonPressedMetricTracker* shelf_button_pressed_metric_tracker)
     : shelf_button_pressed_metric_tracker_(
           shelf_button_pressed_metric_tracker) {}
 
 ShelfButtonPressedMetricTrackerTestAPI::
     ~ShelfButtonPressedMetricTrackerTestAPI() {}
 
 void ShelfButtonPressedMetricTrackerTestAPI::SetTickClock(
     std::unique_ptr<base::TickClock> tick_clock) {
-  shelf_button_pressed_metric_tracker_->tick_clock_.reset(tick_clock.release());
+  shelf_button_pressed_metric_tracker_->tick_clock_ = std::move(tick_clock);
 }
 
 }  // namespace test
 }  // namespace ash