Fix prefs registration in promo code.

chrome/browser/web_resource/notification_promo.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/web_resource/notification_promo.h"
 
 #include <cmath>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 297 matching lines @@
   group_ = base::RandInt(0, num_groups_ - 1);
   WritePrefs();
 }
 
 // static
 void NotificationPromo::RegisterPrefs(PrefRegistrySimple* registry) {
   registry->RegisterDictionaryPref(kPrefPromoObject);
 }
 
 // static
-void NotificationPromo::RegisterUserPrefs(PrefService* prefs,
-                                          PrefRegistrySyncable* registry) {
-  // TODO(dbeam): Remove in M28 when we're reasonably sure all prefs are gone.
+void NotificationPromo::RegisterUserPrefs(PrefRegistrySyncable* registry) {
+  // TODO(dbeam): Registered only for migration. Remove in M28 when
+  // we're reasonably sure all prefs are gone.
   // http://crbug.com/168887
-  // TODO(joi): Remove PrefService parameter; move this to migration code.
   registry->RegisterDictionaryPref(kPrefPromoObject,
                                    PrefRegistrySyncable::UNSYNCABLE_PREF);
-  prefs->ClearPref(kPrefPromoObject);
+}
+
+// static
+void NotificationPromo::MigrateUserPrefs(PrefService* user_prefs) {
+  user_prefs->ClearPref(kPrefPromoObject);
 }
 
 void NotificationPromo::WritePrefs() {
   base::DictionaryValue* ntp_promo = new base::DictionaryValue;
   ntp_promo->SetString(kPrefPromoText, promo_text_);
   ntp_promo->Set(kPrefPromoPayload, promo_payload_->DeepCopy());
   ntp_promo->SetDouble(kPrefPromoStart, start_);
   ntp_promo->SetDouble(kPrefPromoEnd, end_);
 
   ntp_promo->SetInteger(kPrefPromoNumGroups, num_groups_);
@@ skipping 110 matching lines @@
   if (group_ < initial_segment_)
     return start_;
   return start_ +
       std::ceil(static_cast<float>(group_ - initial_segment_ + 1) / increment_)
       * time_slice_;
 }
 
 double NotificationPromo::EndTime() const {
   return end_;
 }