Commit changes after a reset.

base/prefs/pref_filter.h

 // Copyright 2013 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.
 
 #ifndef BASE_PREFS_PREF_FILTER_H_
 #define BASE_PREFS_PREF_FILTER_H_
 
 #include <string>
 
 #include "base/prefs/base_prefs_export.h"
 
 namespace base {
 class DictionaryValue;
 class Value;
 }  // namespace base
 
 // Filters preferences as they are loaded from disk or updated at runtime.
 // Currently supported only by JsonPrefStore.
 class BASE_PREFS_EXPORT PrefFilter {
  public:
   virtual ~PrefFilter() {}
 
   // Receives notification when the pref store data has been loaded but before
   // Observers are notified.
   // Changes made by a PrefFilter during FilterOnLoad do not result in
   // notifications to |PrefStore::Observer|s.
-  virtual void FilterOnLoad(base::DictionaryValue* pref_store_contents) = 0;
+  // Implementations should return true if they modify the dictionary, to allow
+  // the changes to be persisted.
+  virtual bool FilterOnLoad(base::DictionaryValue* pref_store_contents) = 0;
 
   // Receives notification when a pref store value is changed, before Observers
   // are notified.
   virtual void FilterUpdate(const std::string& path) = 0;
 
   // Receives notification when the pref store is about to serialize data
   // contained in |pref_store_contents| to a string.
   virtual void FilterSerializeData(
       const base::DictionaryValue* pref_store_contents) = 0;
 };
 
 #endif  // BASE_PREFS_PREF_FILTER_H_