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

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

Index: chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage_unittest.cc
diff --git a/chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage_unittest.cc b/chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage_unittest.cc
index d51838961a849dc2cfb0e6306cc28be9f7a8eca8..810b30b4649135ca035cc6750f28b502d9677090 100644
--- a/chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage_unittest.cc
+++ b/chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage_unittest.cc
@@ -30,11 +30,13 @@ base::TimeDelta GetExpirationTime(PrefService* pref_service) {
 
 class QuickUnlockStorageUnitTest : public testing::Test {
  protected:
-  QuickUnlockStorageUnitTest() : profile_(new TestingProfile()) {}
+  QuickUnlockStorageUnitTest() : profile_(base::MakeUnique<TestingProfile>()) {}
   ~QuickUnlockStorageUnitTest() override {}
 
   // testing::Test:
-  void SetUp() override { quick_unlock::EnableForTesting(); }
+  void SetUp() override {
+    quick_unlock::EnableForTesting(quick_unlock::PinStorageType::kPrefs);
+  }
 
   content::TestBrowserThreadBundle thread_bundle_;
   std::unique_ptr<TestingProfile> profile_;