cros: Implement cryptohome backend for pin.

chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage.h

Index: chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage.h
diff --git a/chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage.h b/chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage.h
index 7632985e170cd62e84743572cf1231bca165bde1..365675ba1aa0edbd5c76500fdb0201c04bd37165 100644
--- a/chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage.h
+++ b/chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage.h
@@ -5,13 +5,13 @@
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_QUICK_UNLOCK_QUICK_UNLOCK_STORAGE_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_QUICK_UNLOCK_QUICK_UNLOCK_STORAGE_H_
 
+#include "base/callback.h"
 #include "base/memory/ptr_util.h"
 #include "base/time/time.h"
-#include "chrome/browser/chromeos/login/quick_unlock/fingerprint_storage.h"
-#include "chrome/browser/chromeos/login/quick_unlock/pin_storage.h"
 #include "components/keyed_service/core/keyed_service.h"
 
 class PrefService;
+class Profile;
 
 namespace chromeos {
 
@@ -19,9 +19,12 @@ class QuickUnlockStorageTestApi;
 
 namespace quick_unlock {
 
+class FingerprintStorage;
+class PinStoragePrefs;
+
 class QuickUnlockStorage : public KeyedService {
  public:
-  explicit QuickUnlockStorage(PrefService* pref_service);
+  explicit QuickUnlockStorage(Profile* profile);
   ~QuickUnlockStorage() override;
 
   // Mark that the user has had a strong authentication. This means
@@ -39,16 +42,13 @@ class QuickUnlockStorage : public KeyedService {
   // Returns true if fingerprint unlock is currently available.
   bool IsFingerprintAuthenticationAvailable() const;
 
-  // Returns true if PIN unlock is currently available.
-  bool IsPinAuthenticationAvailable() const;
-
-  // Tries to authenticate the given pin. This will consume a pin unlock
-  // attempt. This always returns false if HasStrongAuth returns false.
-  bool TryAuthenticatePin(const std::string& pin);
-
-  FingerprintStorage* fingerprint_storage();
+  FingerprintStorage* fingerprint_storage() const {
+    return fingerprint_storage_.get();
+  }
 
-  PinStorage* pin_storage();
+  // Fetch the underlying pref pin storage. If iteracting with pin generally,
+  // use the PinBackend APIs.
+  PinStoragePrefs* pin_storage_prefs() const { return pin_storage_.get(); }
 
  private:
   friend class chromeos::QuickUnlockStorageTestApi;
@@ -59,7 +59,7 @@ class QuickUnlockStorage : public KeyedService {
   PrefService* pref_service_;
   base::Time last_strong_auth_;
   std::unique_ptr<FingerprintStorage> fingerprint_storage_;
-  std::unique_ptr<PinStorage> pin_storage_;
+  std::unique_ptr<PinStoragePrefs> pin_storage_;
 
   DISALLOW_COPY_AND_ASSIGN(QuickUnlockStorage);
 };