Remove the migration code from content_settings::PrefProvider.

chrome/browser/prefs/pref_model_associator.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/pref_model_associator.h"
 
 #include "base/auto_reset.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/prefs/pref_service.h"
 #include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/prefs/pref_service_syncable.h"
 #include "chrome/common/pref_names.h"
+#include "components/content_settings/core/browser/content_settings_pref_provider.h"
 #include "sync/api/sync_change.h"
 #include "sync/api/sync_error_factory.h"
 #include "sync/protocol/preference_specifics.pb.h"
 #include "sync/protocol/sync.pb.h"
 
 using syncer::PREFERENCES;
 using syncer::PRIORITY_PREFERENCES;
 
 namespace {
 
@@ skipping 287 matching lines @@
     const base::Value& local_value,
     const base::Value& server_value) {
   // This function special cases preferences individually, so don't attempt
   // to merge for all migrated values.
   if (name == prefs::kURLsToRestoreOnStartup ||
       name == prefs::kURLsToRestoreOnStartupOld) {
     return scoped_ptr<base::Value>(
         MergeListValues(local_value, server_value)).Pass();
   }
 
-  if (name == prefs::kContentSettingsPatternPairs) {
+  if (content_settings::PrefProvider::IsContentSettingsExceptionsPref(name)) {

[msramek, 2015/07/27 17:53:01]

This change should have happened back at the time when we introduced these
preferences, not just now when we do the clean-up of the old news. 

However, I didn't know that merging of the local and synced dictionary needs to
be handled explicitly. Fortunately, this would only be a problem if the user
added two exceptions at different machines at the same time; one of them would
be ignored. Unsurprisingly, this is a rare enough case that no one has noticed.

     return scoped_ptr<base::Value>(
         MergeDictionaryValues(local_value, server_value)).Pass();
   }
 
   // If this is not a specially handled preference, server wins.
   return scoped_ptr<base::Value>(server_value.DeepCopy()).Pass();
 }
 
 bool PrefModelAssociator::CreatePrefSyncData(
     const std::string& name,
@@ skipping 309 matching lines @@
 void PrefModelAssociator::NotifySyncedPrefObservers(const std::string& path,
                                                     bool from_sync) const {
   SyncedPrefObserverMap::const_iterator observer_iter =
       synced_pref_observers_.find(path);
   if (observer_iter == synced_pref_observers_.end())
     return;
   SyncedPrefObserverList* observers = observer_iter->second;
   FOR_EACH_OBSERVER(SyncedPrefObserver, *observers,
                     OnSyncedPrefChanged(path, from_sync));
 }