Refactor preference syncing.

chrome/browser/background_mode_manager.cc

 // Copyright (c) 2011 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 <string>
 
 #include "base/base_paths.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
@@ skipping 364 matching lines @@
 #else
   bool background_mode_enabled =
       !command_line->HasSwitch(switches::kDisableBackgroundMode) &&
       !command_line->HasSwitch(switches::kDisableExtensions);
   return background_mode_enabled;
 #endif
 }
 
 // static
 void BackgroundModeManager::RegisterPrefs(PrefService* prefs) {
-  prefs->RegisterBooleanPref(prefs::kUserCreatedLoginItem, false);
+  prefs->RegisterBooleanPref(prefs::kUserCreatedLoginItem,
+                             false,
+                             false /* don't sync pref */);
 }