Fixed regression: various preferences were not persisted when changed from incognito window

chrome/common/pref_store.h

 // Copyright (c) 2011 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 CHROME_COMMON_PREF_STORE_H_
 #define CHROME_COMMON_PREF_STORE_H_
 #pragma once
 
 #include <string>
 
@@ skipping 36 matching lines @@
 
   PrefStore() {}
 
   // Add and remove observers.
   virtual void AddObserver(Observer* observer) {}
   virtual void RemoveObserver(Observer* observer) {}
 
   // Whether the store has completed all asynchronous initialization.
   virtual bool IsInitializationComplete() const;
 
-  // Get the value for a given preference |key| and stores it in |result|.
-  // |result| is only modified if the return value is READ_OK. Ownership of the
-  // |result| value remains with the PrefStore.
+  // Get the value for a given preference |key| and stores it in |*result|.
+  // |*result| is only modified if the return value is READ_OK and if |result|
+  // is not NULL. Ownership of the |*result| value remains with the PrefStore.
   virtual ReadResult GetValue(const std::string& key,
                               const base::Value** result) const = 0;
 
  protected:
   friend class base::RefCounted<PrefStore>;
   virtual ~PrefStore() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PrefStore);
 };
 
 #endif  // CHROME_COMMON_PREF_STORE_H_