Cleanup and style guideline conformance for policy implementation

chrome/common/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_COMMON_PREF_STORE_H_
 #define CHROME_COMMON_PREF_STORE_H_
 #pragma once
 
 class DictionaryValue;
 class Value;
@@ skipping 37 matching lines @@
 
   // Whether the store is in a pseudo-read-only mode where changes are not
   // actually persisted to disk.  This happens in some cases when there are
   // read errors during startup.
   virtual bool ReadOnly() { return true; }
 
   // TODO(danno): PrefValueStore shouldn't allow direct access to the
   // DictionaryValue. Instead, it should have getters that return a
   // richer set of information for a pref, including if the store
   // wants to return the default value for a preference.
-  virtual DictionaryValue* prefs() = 0;
+  virtual DictionaryValue* prefs() const = 0;
 
   virtual PrefReadError ReadPrefs() = 0;
 
   virtual bool WritePrefs() { return true; }
 
   virtual void ScheduleWritePrefs() { }
 };
 
 #endif  // CHROME_COMMON_PREF_STORE_H_