components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/password_manager/password_store_x.h

Index: chrome/browser/password_manager/password_store_x.h
diff --git a/chrome/browser/password_manager/password_store_x.h b/chrome/browser/password_manager/password_store_x.h
index 3e01da7e84a89ae78a741d2a6e83d33856b1b1c5..80c852724ba2a91dc66a90b51d3a56fd15c98b90 100644
--- a/chrome/browser/password_manager/password_store_x.h
+++ b/chrome/browser/password_manager/password_store_x.h
@@ -13,9 +13,12 @@
 
 class LoginDatabase;
 class PrefService;
-class PrefRegistrySyncable;
 class Profile;
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 // PasswordStoreX is used on Linux and other non-Windows, non-Mac OS X
 // operating systems. It uses a "native backend" to actually store the password
 // data when such a backend is available, and otherwise falls back to using the
@@ -57,7 +60,7 @@ class PasswordStoreX : public PasswordStoreDefault {
 
 #if !defined(OS_MACOSX) && !defined(OS_CHROMEOS) && defined(OS_POSIX)
   // Registers the pref setting used for the methods below.
-  static void RegisterUserPrefs(PrefRegistrySyncable* registry);
+  static void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
   // Returns true if passwords have been tagged with the local profile id.
   static bool PasswordsUseLocalProfileId(PrefService* prefs);