WIP: Pref service: use the incognito support from Chrome

components/prefs/pref_value_store.h

 // 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.
 
 #ifndef COMPONENTS_PREFS_PREF_VALUE_STORE_H_
 #define COMPONENTS_PREFS_PREF_VALUE_STORE_H_
 
 #include <map>
 #include <string>
 #include <type_traits>
@@ skipping 62 matching lines @@
   //
   // |pref_notifier| facilitates broadcasting preference change notifications
   // to the world.
   PrefValueStore(PrefStore* managed_prefs,
                  PrefStore* supervised_user_prefs,
                  PrefStore* extension_prefs,
                  PrefStore* command_line_prefs,
                  PrefStore* user_prefs,
                  PrefStore* recommended_prefs,
                  PrefStore* default_prefs,
-                 PrefNotifier* pref_notifier);
+                 PrefNotifier* pref_notifier,
+                 PrefStore* incognito_prefs = nullptr);
+  // TODO(tibell): Add incognito store as an option.
   virtual ~PrefValueStore();
 
   // Creates a clone of this PrefValueStore with PrefStores overwritten
   // by the parameters passed, if unequal NULL.
   PrefValueStore* CloneAndSpecialize(PrefStore* managed_prefs,
                                      PrefStore* supervised_user_prefs,
                                      PrefStore* extension_prefs,
                                      PrefStore* command_line_prefs,
                                      PrefStore* user_prefs,
                                      PrefStore* recommended_prefs,
                                      PrefStore* default_prefs,
-                                     PrefNotifier* pref_notifier);
+                                     PrefNotifier* pref_notifier,
+                                     PrefStore* incognito_prefs = nullptr);
 
   // A PrefValueStore can have exactly one callback that is directly
   // notified of preferences changing in the store. This does not
   // filter through the PrefNotifier mechanism, which may not forward
   // certain changes (e.g. unregistered prefs).
   void set_callback(const PrefChangedCallback& callback);
 
   // Gets the value for the given preference name that has the specified value
   // type. Values stored in a PrefStore that have the matching |name| but
   // a non-matching |type| are silently skipped. Returns true if a valid value
@@ skipping 161 matching lines @@
 struct hash<PrefValueStore::PrefStoreType> {
   size_t operator()(PrefValueStore::PrefStoreType type) const {
     return std::hash<
         std::underlying_type<PrefValueStore::PrefStoreType>::type>()(type);
   }
 };
 
 }  // namespace std
 
 #endif  // COMPONENTS_PREFS_PREF_VALUE_STORE_H_