Remove PrefServiceSimple, replacing it with PrefService and PrefRegistrySimple.

chrome/browser/chromeos/login/user_manager.h

Index: chrome/browser/chromeos/login/user_manager.h
diff --git a/chrome/browser/chromeos/login/user_manager.h b/chrome/browser/chromeos/login/user_manager.h
index d812fce4b994c26a6e132ef5165b8ec258458be7..1a5934f10acd5ac7e12dfadb905a711dfac76789 100644
--- a/chrome/browser/chromeos/login/user_manager.h
+++ b/chrome/browser/chromeos/login/user_manager.h
@@ -10,7 +10,7 @@
 #include "base/memory/singleton.h"
 #include "chrome/browser/chromeos/login/user.h"
 
-class PrefServiceSimple;
+class PrefRegistrySimple;
 
 namespace chromeos {
 
@@ -63,7 +63,7 @@ class UserManager {
   static UserManager* Set(UserManager* mock);
 
   // Registers user manager preferences.
-  static void RegisterPrefs(PrefServiceSimple* local_state);
+  static void RegisterPrefs(PrefRegistrySimple* local_state);
 
   // Indicates imminent shutdown, allowing the UserManager to remove any
   // observers it has registered.