Take out and generalize user prefs overriding from IncognitoUserPrefStore.

chrome/browser/prefs/overlay_user_pref_store.h

Index: chrome/browser/prefs/overlay_user_pref_store.h
diff --git a/chrome/browser/prefs/incognito_user_pref_store.h b/chrome/browser/prefs/overlay_user_pref_store.h
similarity index 65%
copy from chrome/browser/prefs/incognito_user_pref_store.h
copy to chrome/browser/prefs/overlay_user_pref_store.h
index b5be17eb7c66b728feb9a24615738884c9bc1da0..1776c465466633eb3db7a691e0b6510004fef42e 100644
--- a/chrome/browser/prefs/incognito_user_pref_store.h
+++ b/chrome/browser/prefs/overlay_user_pref_store.h
@@ -2,13 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_PREFS_INCOGNITO_USER_PREF_STORE_H_
-#define CHROME_BROWSER_PREFS_INCOGNITO_USER_PREF_STORE_H_
+#ifndef CHROME_BROWSER_PREFS_OVERLAY_USER_PREF_STORE_H_
+#define CHROME_BROWSER_PREFS_OVERLAY_USER_PREF_STORE_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/hash_tables.h"

[Mattias Nissler (ping if slow), 2011/11/14 12:04:55]

remove this and instead #include <map>

[mnaganov (inactive), 2011/11/14 12:07:31]

Done.

 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "chrome/browser/prefs/pref_value_map.h"
@@ -18,14 +19,14 @@
 // 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 IncognitoUserPrefStore : public PersistentPrefStore,
-                               public PrefStore::Observer {
+class OverlayUserPrefStore : public PersistentPrefStore,
+                             public PrefStore::Observer {
  public:
-  explicit IncognitoUserPrefStore(PersistentPrefStore* underlay);
-  virtual ~IncognitoUserPrefStore();
+  explicit OverlayUserPrefStore(PersistentPrefStore* underlay);
+  virtual ~OverlayUserPrefStore();
 
   // Returns true if a value has been set for the |key| in this
-  // IncognitoUserPrefStore, i.e. if it potentially overrides a value
+  // OverlayUserPrefStore, i.e. if it potentially overrides a value
   // from the |underlay_|.
   virtual bool IsSetInOverlay(const std::string& key) const;
 
@@ -50,22 +51,34 @@ class IncognitoUserPrefStore : public PersistentPrefStore,
   virtual void CommitPendingWrite();
   virtual void ReportValueChanged(const std::string& key);
 
+ protected:
+  void RegisterOverlayProperty(const std::string& key);
+  void RegisterOverlayProperty(const std::string& overlay_key,
+                               const std::string& underlay_key);
+
  private:
+  friend class OverlayUserPrefStoreTest;
+
+  typedef std::map<std::string, std::string> NamesMap;
+
   // Methods of PrefStore::Observer.
   virtual void OnPrefValueChanged(const std::string& key);
   virtual void OnInitializationCompleted(bool succeeded);
 
+  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. All preferences
-  // that store information about the browsing history or behavior of the user
-  // should have this property.
-  virtual bool ShallBeStoredInOverlay(const std::string& key) const;
+  // 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(IncognitoUserPrefStore);
+  DISALLOW_COPY_AND_ASSIGN(OverlayUserPrefStore);
 };
 
-#endif  // CHROME_BROWSER_PREFS_INCOGNITO_USER_PREF_STORE_H_
+#endif  // CHROME_BROWSER_PREFS_OVERLAY_USER_PREF_STORE_H_