cros: Implement cryptohome backend for pin.

chrome/browser/chromeos/login/lock/screen_locker.cc

Index: chrome/browser/chromeos/login/lock/screen_locker.cc
diff --git a/chrome/browser/chromeos/login/lock/screen_locker.cc b/chrome/browser/chromeos/login/lock/screen_locker.cc
index 7e1a29aa46ee77b9d397d6552773a70e69d1a8c7..50091b243aba329aed993b1a6bf6b1a5b77a6c06 100644
--- a/chrome/browser/chromeos/login/lock/screen_locker.cc
+++ b/chrome/browser/chromeos/login/lock/screen_locker.cc
@@ -30,6 +30,8 @@
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
 #include "chrome/browser/chromeos/login/lock/webui_screen_locker.h"
+#include "chrome/browser/chromeos/login/quick_unlock/fingerprint_storage.h"
+#include "chrome/browser/chromeos/login/quick_unlock/pin_backend.h"
 #include "chrome/browser/chromeos/login/quick_unlock/quick_unlock_factory.h"
 #include "chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage.h"
 #include "chrome/browser/chromeos/login/session/user_session_manager.h"
@@ -326,10 +328,10 @@ void ScreenLocker::OnAuthSuccess(const UserContext& user_context) {
     // 2. If the user signed in with cryptohome keys, then the PIN timeout is
     //    going to be reset as well, so it is safe to reset the unlock attempt
     //    count.
+    quick_unlock::PinBackend::NotifyAuthentication(user_context.GetAccountId());
     quick_unlock::QuickUnlockStorage* quick_unlock_storage =
         quick_unlock::QuickUnlockFactory::GetForUser(user);
     if (quick_unlock_storage) {
-      quick_unlock_storage->pin_storage()->ResetUnlockAttemptCount();
       quick_unlock_storage->fingerprint_storage()->ResetUnlockAttemptCount();
     }
 
@@ -397,15 +399,29 @@ void ScreenLocker::Authenticate(const UserContext& user_context) {
     int dummy_value;
     if (unlock_attempt_type_ == AUTH_PIN &&
         base::StringToInt(pin, &dummy_value)) {
-      quick_unlock::QuickUnlockStorage* quick_unlock_storage =
-          quick_unlock::QuickUnlockFactory::GetForUser(user);
-      if (quick_unlock_storage &&
-          quick_unlock_storage->TryAuthenticatePin(pin)) {
-        OnAuthSuccess(user_context);
-        return;
-      }
+      quick_unlock::PinBackend::TryAuthenticate(
+          user_context.GetAccountId(), pin,
+          base::Bind(&ScreenLocker::OnPinAttemptDone,
+                     weak_factory_.GetWeakPtr(), user_context));
+      return;
     }
+  }
+
+  ContinueAuthenticate(user_context);
+}
+
+void ScreenLocker::OnPinAttemptDone(const UserContext& user_context,
+                                    bool success) {
+  if (success)
+    OnAuthSuccess(user_context);
+  else
+    ContinueAuthenticate(user_context);
+}
 
+void ScreenLocker::ContinueAuthenticate(
+    const chromeos::UserContext& user_context) {
+  const user_manager::User* user = FindUnlockUser(user_context.GetAccountId());
+  if (user) {
     // Special case: supervised users. Use special authenticator.
     if (user->GetType() == user_manager::USER_TYPE_SUPERVISED) {
       UserContext updated_context = ChromeUserManager::Get()