Cleanup and style guideline conformance for policy implementation

chrome/browser/prefs/default_pref_store.h

 // Copyright (c) 2010 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_BROWSER_PREFS_DEFAULT_PREF_STORE_H_
 #define CHROME_BROWSER_PREFS_DEFAULT_PREF_STORE_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/scoped_ptr.h"
 #include "chrome/common/pref_store.h"
 
 // This PrefStore keeps track of default preference values set when a
 // preference is registered with the PrefService.
 class DefaultPrefStore : public PrefStore {
  public:
   DefaultPrefStore();
   virtual ~DefaultPrefStore();
 
   // PrefStore methods:
-  virtual DictionaryValue* prefs();
+  virtual DictionaryValue* prefs() const;
   virtual PrefStore::PrefReadError ReadPrefs();
 
  private:
   // The default preference values.
   scoped_ptr<DictionaryValue> prefs_;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultPrefStore);
 };
 
 #endif  // CHROME_BROWSER_PREFS_DEFAULT_PREF_STORE_H_