Make browsing_data component a layered component

components/browsing_data/browsing_data_utils.cc

-// Copyright 2016 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 "components/browsing_data/browsing_data_utils.h"
-
-namespace browsing_data {
-
-base::Time CalculateBeginDeleteTime(TimePeriod time_period) {
-  base::TimeDelta diff;
-  base::Time delete_begin_time = base::Time::Now();
-  switch (time_period) {
-    case LAST_HOUR:
-      diff = base::TimeDelta::FromHours(1);
-      break;
-    case LAST_DAY:
-      diff = base::TimeDelta::FromHours(24);
-      break;
-    case LAST_WEEK:
-      diff = base::TimeDelta::FromHours(7 * 24);
-      break;
-    case FOUR_WEEKS:
-      diff = base::TimeDelta::FromHours(4 * 7 * 24);
-      break;
-    case EVERYTHING:
-      delete_begin_time = base::Time();
-      break;
-  }
-  return delete_begin_time - diff;
-}
-
-}  // namespace browsing_data