Revert "Eliminate all code related to the AutomaticProfileResetter."

chrome/browser/prefs/chrome_pref_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/prefs/chrome_pref_service_factory.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 136 matching lines @@
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
 #if !defined(OS_ANDROID)
   {
     11, prefs::kPinnedTabs,
     PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
 #endif
   {
+    13, prefs::kProfileResetPromptMemento,
+    PrefHashFilter::ENFORCE_ON_LOAD,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC

[gab, 2014/09/03 14:51:39]

This should be okay; either it got cleared, or it still exists and has a valid
MAC (i.e. the last Chrome that ran had this as a protected pref).

Even safer/cleaner would be to use new pref names though IMO as suggested above.

[engedy, 2014/09/04 11:59:45]

I went for a middle-ground solution, please see my response to the comment
before.

+  },
+  {
     14, DefaultSearchManager::kDefaultSearchProviderDataPrefName,
     PrefHashFilter::NO_ENFORCEMENT,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
   {
     // Protecting kPreferenceResetTime does two things:
     //  1) It ensures this isn't accidently set by someone stomping the pref
     //     file.
     //  2) More importantly, it declares kPreferenceResetTime as a protected
     //     pref which is required for it to be visible when queried via the
@@ skipping 350 matching lines @@
 
 void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
   ProfilePrefStoreManager::RegisterProfilePrefs(registry);
 }
 
 void RegisterPrefs(PrefRegistrySimple* registry) {
   ProfilePrefStoreManager::RegisterPrefs(registry);
 }
 
 }  // namespace chrome_prefs