Move the bits of Prefs where production code has only trivially easy

chrome/browser/prefs/overlay_user_pref_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 CHROME_BROWSER_PREFS_OVERLAY_USER_PREF_STORE_H_
-#define CHROME_BROWSER_PREFS_OVERLAY_USER_PREF_STORE_H_
-
-#include <map>
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/memory/ref_counted.h"
-#include "base/observer_list.h"
-#include "chrome/browser/prefs/pref_value_map.h"
-#include "chrome/common/persistent_pref_store.h"
-
-// PersistentPrefStore that directs all write operations into an in-memory
-// PrefValueMap. Read operations are first answered by the PrefValueMap.
-// If the PrefValueMap does not contain a value for the requested key,
-// the look-up is passed on to an underlying PersistentPrefStore |underlay_|.
-class OverlayUserPrefStore : public PersistentPrefStore,
-                             public PrefStore::Observer {
- public:
-  explicit OverlayUserPrefStore(PersistentPrefStore* underlay);
-
-  // Returns true if a value has been set for the |key| in this
-  // OverlayUserPrefStore, i.e. if it potentially overrides a value
-  // from the |underlay_|.
-  virtual bool IsSetInOverlay(const std::string& key) const;
-
-  // Methods of PrefStore.
-  virtual void AddObserver(PrefStore::Observer* observer) OVERRIDE;
-  virtual void RemoveObserver(PrefStore::Observer* observer) OVERRIDE;
-  virtual size_t NumberOfObservers() const OVERRIDE;
-  virtual bool IsInitializationComplete() const OVERRIDE;
-  virtual ReadResult GetValue(const std::string& key,
-                              const base::Value** result) const OVERRIDE;
-
-  // Methods of PersistentPrefStore.
-  virtual ReadResult GetMutableValue(const std::string& key,
-                                     base::Value** result) OVERRIDE;
-  virtual void SetValue(const std::string& key, base::Value* value) OVERRIDE;
-  virtual void SetValueSilently(const std::string& key,
-                                base::Value* value) OVERRIDE;
-  virtual void RemoveValue(const std::string& key) OVERRIDE;
-  virtual void MarkNeedsEmptyValue(const std::string& key) OVERRIDE;
-  virtual bool ReadOnly() const OVERRIDE;
-  virtual PrefReadError GetReadError() const OVERRIDE;
-  virtual PrefReadError ReadPrefs() OVERRIDE;
-  virtual void ReadPrefsAsync(ReadErrorDelegate* delegate) OVERRIDE;
-  virtual void CommitPendingWrite() OVERRIDE;
-  virtual void ReportValueChanged(const std::string& key) OVERRIDE;
-
-  // Methods of PrefStore::Observer.
-  virtual void OnPrefValueChanged(const std::string& key) OVERRIDE;
-  virtual void OnInitializationCompleted(bool succeeded) OVERRIDE;
-
-  void RegisterOverlayPref(const std::string& key);
-  void RegisterOverlayPref(const std::string& overlay_key,
-                           const std::string& underlay_key);
-
- protected:
-  virtual ~OverlayUserPrefStore();
-
- private:
-  typedef std::map<std::string, std::string> NamesMap;
-
-  const std::string& GetOverlayKey(const std::string& underlay_key) const;
-  const std::string& GetUnderlayKey(const std::string& overlay_key) const;
-
-  // Returns true if |key| corresponds to a preference that shall be stored in
-  // an in-memory PrefStore that is not persisted to disk.
-  bool ShallBeStoredInOverlay(const std::string& key) const;
-
-  ObserverList<PrefStore::Observer, true> observers_;
-  PrefValueMap overlay_;
-  scoped_refptr<PersistentPrefStore> underlay_;
-  NamesMap overlay_to_underlay_names_map_;
-  NamesMap underlay_to_overlay_names_map_;
-
-  DISALLOW_COPY_AND_ASSIGN(OverlayUserPrefStore);
-};
-
-#endif  // CHROME_BROWSER_PREFS_OVERLAY_USER_PREF_STORE_H_