Implement pin storage backend.

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

Index: chrome/browser/chromeos/login/quick_unlock/pin_storage.h
diff --git a/chrome/browser/chromeos/login/quick_unlock/pin_storage.h b/chrome/browser/chromeos/login/quick_unlock/pin_storage.h
new file mode 100644
index 0000000000000000000000000000000000000000..2a630307f84b885dc73db2e9038c297661a78cfc
--- /dev/null
+++ b/chrome/browser/chromeos/login/quick_unlock/pin_storage.h
@@ -0,0 +1,61 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_CHROMEOS_LOGIN_QUICK_UNLOCK_PIN_STORAGE_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_QUICK_UNLOCK_PIN_STORAGE_H_
+
+#include <string>
+
+#include "base/time/time.h"
+#include "components/pref_registry/pref_registry_syncable.h"
+
+class Profile;
+
+namespace chromeos {
+
+// TODO(jdufault): Figure out the UX we want on the lock screen when there are
+// multiple users. We will be storing either global or per-user unlock state. If
+// we end up storing global unlock state, we can pull the unlock attempt and
+// strong-auth code out of this class.
+
+class PinStorage {
+ public:
+  // Fetch the data for the given profile. Each profile can have different
+  // pin/unlock state.
+  static PinStorage* GetInstance(Profile* profile);

[stevenjb, 2016/05/16 16:33:34]

We should use a BrowserContextKeyedServiceFactory for this. E.g. see
CaptivePortalService and CaptivePortalServiceFactory.

[jdufault, 2016/05/16 22:08:48]

Ah, the factory separation cleans things up quite a bit. Thanks.

+
+  // Registers profile prefs.
+  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
+
+  PinStorage();
+  virtual ~PinStorage();
+
+  // Mark in storage that the user has had a strong authentication. This means
+  // that they authenticated with their password, for example. PIN unlock will
+  // timeout after a delay.
+  virtual void MarkStrongAuth() = 0;
+  virtual base::TimeDelta TimeSinceLastStrongAuth() = 0;
+
+  // Add a PIN unlock attempt count.
+  virtual void AddUnlockAttempt() = 0;
+  virtual void ResetUnlockAttemptCount() = 0;
+  virtual int UnlockAttemptCount() = 0;
+
+  // PIN storage management.
+  virtual bool HasPin() const = 0;
+  virtual void SetPin(const std::string& raw_pin) = 0;
+  virtual void RemovePin() = 0;
+
+  // The salt and hash for the stored pin. These methods return empty values if
+  // HasPin returns false.
+  virtual std::string pin_salt() const = 0;
+  virtual std::string pin_secret() const = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(PinStorage);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_QUICK_UNLOCK_PIN_STORAGE_H_