cros: Add PinStorageProvider enum which describes pin backend in use.

chrome/browser/chromeos/login/quick_unlock/quick_unlock_utils.cc

Index: chrome/browser/chromeos/login/quick_unlock/quick_unlock_utils.cc
diff --git a/chrome/browser/chromeos/login/quick_unlock/quick_unlock_utils.cc b/chrome/browser/chromeos/login/quick_unlock/quick_unlock_utils.cc
index f3a306c6ccf5ab25c2c5ebe2a7bede9a4e88da90..3109378a50b17463c05f91819a56a8886b31914d 100644
--- a/chrome/browser/chromeos/login/quick_unlock/quick_unlock_utils.cc
+++ b/chrome/browser/chromeos/login/quick_unlock/quick_unlock_utils.cc
@@ -18,7 +18,12 @@ namespace chromeos {
 namespace quick_unlock {
 
 namespace {
+// Quick unlock is enabled regardless of flags.
 bool enable_for_testing_ = false;
+// If testing is enabled, PIN will use prefs as backend. Otherwise, it will use
+// cryptohome.
+PinStorageProvider testing_pin_storage_provider_ = PinStorageProvider::Prefs;
+
 // Options for the quick unlock whitelist.
 const char kQuickUnlockWhitelistOptionAll[] = "all";
 const char kQuickUnlockWhitelistOptionPin[] = "PIN";
@@ -87,6 +92,15 @@ bool IsPinEnabled(PrefService* pref_service) {
   return base::FeatureList::IsEnabled(features::kQuickUnlockPin);
 }
 
+PinStorageProvider GetPinStorageProvider() {
+  if (enable_for_testing_)
+    return testing_pin_storage_provider_;
+
+  if (base::FeatureList::IsEnabled(features::kQuickUnlockPinSignin))
+    return PinStorageProvider::Cryptohome;
+  return PinStorageProvider::Prefs;
+}
+
 bool IsFingerprintEnabled() {
   if (enable_for_testing_)
     return true;
@@ -95,8 +109,9 @@ bool IsFingerprintEnabled() {
   return base::FeatureList::IsEnabled(features::kQuickUnlockFingerprint);
 }
 
-void EnableForTesting() {
+void EnableForTesting(PinStorageProvider pin_storage_provider) {
   enable_for_testing_ = true;
+  testing_pin_storage_provider_ = pin_storage_provider;
 }
 
 }  // namespace quick_unlock