Remove PrefServiceSimple, replacing it with PrefService and PrefRegistrySimple.

chrome/browser/prefs/pref_registrar_simple.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_PREF_SERVICE_SIMPLE_H_
-#define CHROME_BROWSER_PREFS_PREF_SERVICE_SIMPLE_H_
+#ifndef CHROME_BROWSER_PREFS_PREF_REGISTRAR_SIMPLE_H_
+#define CHROME_BROWSER_PREFS_PREF_REGISTRAR_SIMPLE_H_
 
-#include "chrome/browser/prefs/pref_service.h"
+#include <string>
 
-// A simple PrefService implementation.
-class PrefServiceSimple : public PrefService {
+#include "base/values.h"
+
+class FilePath;
+class PrefService;
+
+// A class for performing registration of simple types to a standard
+// PrefService.
+class PrefRegistrarSimple {
  public:
-  // You may wish to use PrefServiceBuilder or one of its subclasses
-  // for simplified construction.
-  PrefServiceSimple(
-      PrefNotifierImpl* pref_notifier,
-      PrefValueStore* pref_value_store,
-      PersistentPrefStore* user_prefs,
-      DefaultPrefStore* default_store,
-      base::Callback<void(PersistentPrefStore::PrefReadError)>
-          read_error_callback,
-      bool async);
-  virtual ~PrefServiceSimple();
+  // Creates a registrar to register preferences with the specified
+  // PrefService. The caller is responsible for ensuring that the
+  // lifetime of |pref_service| exceeds the lifetime of this object.
+  PrefRegistrarSimple(PrefService* pref_service);
 
   void RegisterBooleanPref(const char* path, bool default_value);
   void RegisterIntegerPref(const char* path, int default_value);
   void RegisterDoublePref(const char* path, double default_value);
   void RegisterStringPref(const char* path, const std::string& default_value);
   void RegisterFilePathPref(const char* path, const FilePath& default_value);
   void RegisterListPref(const char* path);
   void RegisterDictionaryPref(const char* path);
   void RegisterListPref(const char* path, base::ListValue* default_value);
   void RegisterDictionaryPref(
       const char* path, base::DictionaryValue* default_value);
   void RegisterInt64Pref(const char* path,
                          int64 default_value);
 
+  void UnregisterPreference(const char* path);
+
  private:
-  DISALLOW_COPY_AND_ASSIGN(PrefServiceSimple);
+  PrefService* pref_service_;

[Mattias Nissler (ping if slow), 2013/01/03 13:11:16]

Ah, so I had a different thing in mind: Make PrefRegistrar an interface like so:

class PrefRegistrar {
 public:
  virtual ~PrefRegistrar();

  virtual ValueType GetType(const std::string& pref_name) = 0;
  virtual const base::Value* GetDefaultValue(const std::string& pref_name) = 0;
};

This is the type we'd pass to PrefService in a constructor parameter and it
would keep a pointer. PrefService would also wrap it in a PrefStore adapter for
use as |default_store|.

Then, derived classes could add the registration functions with or without the
sync parameter as appropriate.

+
+  DISALLOW_COPY_AND_ASSIGN(PrefRegistrarSimple);
 };
 
-#endif  // CHROME_BROWSER_PREFS_PREF_SERVICE_SIMPLE_H_
+#endif  // CHROME_BROWSER_PREFS_PREF_REGISTRAR_SIMPLE_H_