Remove most occurences of PrefRegistrySyncable::UNSYNCABLE_PREF

chrome/browser/policy/cloud/user_policy_signin_service_factory.cc

 // Copyright (c) 2012 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/policy/cloud/user_policy_signin_service_factory.h"
 
 #include "base/memory/ref_counted.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/policy/cloud/user_cloud_policy_manager_factory.h"
@@ skipping 80 matching lines @@
 #else
   // Create this object when the profile is created so it can track any
   // user signin activity.
   return true;
 #endif
 }
 
 void UserPolicySigninServiceFactory::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* user_prefs) {
 #if defined(OS_ANDROID) || defined(OS_IOS)
-  user_prefs->RegisterInt64Pref(
-      prefs::kLastPolicyCheckTime,
-      0,
-      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+  user_prefs->RegisterInt64Pref(prefs::kLastPolicyCheckTime, 0);
 #endif
 }
 
 }  // namespace policy