Manual revert of Timezone auto update option should be available by default.

chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc

 // Copyright 2014 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 "chrome/browser/chromeos/login/users/chrome_user_manager_impl.h"
 
 #include <cstddef>
 #include <set>
 
 #include "ash/multi_profile_uma.h"
@@ skipping 1030 matching lines @@
     if ((users + GetUsersAllowedForMultiProfile().size()) > 1)
       ash::MultiProfileUMA::RecordUserCount(users);
   }
 
   base::debug::SetCrashKeyValue(
       crash_keys::kNumberOfUsers,
       base::StringPrintf("%" PRIuS, GetLoggedInUsers().size()));
 }
 
 void ChromeUserManagerImpl::UpdateUserTimeZoneRefresher(Profile* profile) {
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          chromeos::switches::kDisableTimeZoneTrackingOption)) {
+  if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
+          chromeos::switches::kEnableTimeZoneTrackingOption)) {
     return;
   }
 
   user_manager::User* user = ProfileHelper::Get()->GetUserByProfile(profile);
   if (user == NULL)
     return;
 
   // In Multi-Profile mode only primary user settings are in effect.
   if (user != user_manager::UserManager::Get()->GetPrimaryUser())
     return;
@@ skipping 11 matching lines @@
 
   if (profile->GetPrefs()->GetBoolean(prefs::kResolveTimezoneByGeolocation) &&
       !system::HasSystemTimezonePolicy()) {
     g_browser_process->platform_part()->GetTimezoneResolver()->Start();
   } else {
     g_browser_process->platform_part()->GetTimezoneResolver()->Stop();
   }
 }
 
 }  // namespace chromeos