Implement additional parts of the new ui for CBD.

components/browsing_data/core/pref_names.h

 // 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.
 
 #ifndef COMPONENTS_BROWSING_DATA_CORE_PREF_NAMES_H_
 #define COMPONENTS_BROWSING_DATA_CORE_PREF_NAMES_H_
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 namespace browsing_data {
 
 namespace prefs {
 
 extern const char kDeleteTimePeriod[];
 
 extern const char kDeleteBrowsingHistory[];
 extern const char kDeleteDownloadHistory[];
 extern const char kDeleteCache[];
 extern const char kDeleteCookies[];
 extern const char kDeletePasswords[];
 extern const char kDeleteFormData[];
 extern const char kDeleteHostedAppsData[];
 extern const char kDeleteMediaLicenses[];
 
 extern const char kLastClearBrowsingDataTime[];
 extern const char kClearBrowsingDataHistoryNoticeShownTimes[];
 
+extern const char kLastClearBrowsingDataTab[];
+
 // Registers the Clear Browsing Data UI prefs.
 void RegisterBrowserUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
 }  // namespace prefs
 
 }  // namespace browsing_data
 
 #endif  // COMPONENTS_BROWSING_DATA_CORE_PREF_NAMES_H_