Refactor preference syncing.

chrome/browser/ui/webui/options/extension_settings_handler.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 "chrome/browser/extensions/extensions_ui.h"
 
 #include <algorithm>
 
 #include "base/base64.h"
 #include "base/callback.h"
@@ skipping 901 matching lines @@
 }
 
 // static
 RefCountedMemory* ExtensionsUI::GetFaviconResourceBytes() {
   return ResourceBundle::GetSharedInstance().
       LoadDataResourceBytes(IDR_PLUGIN);
 }
 
 // static
 void ExtensionsUI::RegisterUserPrefs(PrefService* prefs) {
-  prefs->RegisterBooleanPref(prefs::kExtensionsUIDeveloperMode, false);
+  prefs->RegisterBooleanPref(prefs::kExtensionsUIDeveloperMode,
+                             false,
+                             PrefService::SYNCABLE_PREF);
 }