cros: Implement cryptohome backend for pin.

chrome/browser/prefs/browser_prefs.cc

Index: chrome/browser/prefs/browser_prefs.cc
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 500f488c97d5a4a39074b41cf565a88752dfc948..e350f09509c7f5dcad7c87b21e6cf822f6e34b9f 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -190,7 +190,7 @@
 #include "chrome/browser/chromeos/first_run/first_run.h"
 #include "chrome/browser/chromeos/login/demo_mode/demo_mode_detector.h"
 #include "chrome/browser/chromeos/login/quick_unlock/fingerprint_storage.h"
-#include "chrome/browser/chromeos/login/quick_unlock/pin_storage.h"
+#include "chrome/browser/chromeos/login/quick_unlock/pin_storage_prefs.h"
 #include "chrome/browser/chromeos/login/quick_unlock/quick_unlock_utils.h"
 #include "chrome/browser/chromeos/login/saml/saml_offline_signin_limiter.h"
 #include "chrome/browser/chromeos/login/session/user_session_manager.h"
@@ -608,7 +608,7 @@ void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
   chromeos::KeyPermissions::RegisterProfilePrefs(registry);
   chromeos::MultiProfileUserController::RegisterProfilePrefs(registry);
   chromeos::quick_unlock::FingerprintStorage::RegisterProfilePrefs(registry);
-  chromeos::quick_unlock::PinStorage::RegisterProfilePrefs(registry);
+  chromeos::quick_unlock::PinStoragePrefs::RegisterProfilePrefs(registry);
   chromeos::Preferences::RegisterProfilePrefs(registry);
   chromeos::PrintersManager::RegisterProfilePrefs(registry);
   chromeos::quick_unlock::RegisterProfilePrefs(registry);