Introduce PrefRegistrySyncable, simplifying PrefServiceSyncable.

chrome/browser/prefs/incognito_mode_prefs.cc

Index: chrome/browser/prefs/incognito_mode_prefs.cc
diff --git a/chrome/browser/prefs/incognito_mode_prefs.cc b/chrome/browser/prefs/incognito_mode_prefs.cc
index 958140b2ed46cb71dd280c632f94c3f789c92658..7edb49f8ccae963e14ed959aef2d11a5f6ca0ea5 100644
--- a/chrome/browser/prefs/incognito_mode_prefs.cc
+++ b/chrome/browser/prefs/incognito_mode_prefs.cc
@@ -6,6 +6,7 @@
 
 #include "base/command_line.h"
 #include "base/logging.h"
+#include "chrome/browser/prefs/pref_registry_syncable.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
@@ -52,11 +53,11 @@ void IncognitoModePrefs::SetAvailability(PrefService* prefs,
 }
 
 // static
-void IncognitoModePrefs::RegisterUserPrefs(PrefServiceSyncable* pref_service) {
-  DCHECK(pref_service);
-  pref_service->RegisterIntegerPref(prefs::kIncognitoModeAvailability,
-                                    IncognitoModePrefs::ENABLED,
-                                    PrefServiceSyncable::UNSYNCABLE_PREF);
+void IncognitoModePrefs::RegisterUserPrefs(PrefRegistrySyncable* registry) {
+  DCHECK(registry);

[Mattias Nissler (ping if slow), 2013/02/06 17:53:33]

nit: not needed, we crash below if the pointer is NULL.

[Jói, 2013/02/07 14:52:32]

Done.

+  registry->RegisterIntegerPref(prefs::kIncognitoModeAvailability,
+                                IncognitoModePrefs::ENABLED,
+                                PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 // static