Add FingerprintUnlock KeyedService for each profile

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

+// Copyright 2017 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_FINGERPRINT_UNLOCK_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_QUICK_UNLOCK_FINGERPRINT_UNLOCK_H_
+
+#include <string>
+#include <vector>
+
+#include "base/time/time.h"
+#include "components/keyed_service/core/keyed_service.h"
+
+class PrefService;
+
+namespace chromeos {
+
+class FingerprintUnlockTestApi;
+
+namespace quick_unlock {
+
+class FingerprintUnlock : public KeyedService {
+ public:
+  static const int kMaximumUnlockAttempts = 5;
+
+  explicit FingerprintUnlock(PrefService* pref_service);
+  ~FingerprintUnlock() override;
+
+  // Mark that the user has had a strong authentication. This means
+  // that they authenticated with their password, for example. Fingerprint
+  // unlock will timeout after a delay.
+  void MarkStrongAuth();
+  // Returns true if the user has been strongly authenticated.
+  bool HasStrongAuth() const;
+  // Returns true if the user has fingerprint enrollments registered.
+  bool HasEnrollment() const;
+  // Returns the time since the last strong authentication. This should not be
+  // called if HasStrongAuth returns false.
+  base::TimeDelta TimeSinceLastStrongAuth() const;
+
+  // Add a fingerprint unlock attempt count.
+  void AddUnlockAttempt();
+  // Reset the number of unlock attempts to 0.
+  void ResetUnlockAttemptCount();
+  // Returns the number of unlock attempts.
+  int unlock_attempt_count() const { return unlock_attempt_count_; }

[stevenjb, 2017/02/27 17:25:34]

nit: comment the variable instead (if at all, the name is pretty clear) and
declare simple accessors last.

[xiaoyinh(OOO Sep 11-29), 2017/02/27 21:36:42]

Done.

+
+  // Returns true if fingerprint unlock is currently available.
+  bool IsFingerprintAuthenticationAvailable() const;

[stevenjb, 2017/02/27 17:25:34]

The grouping of the public methods is unclear. I would prefer a blank line
between each method.

[xiaoyinh(OOO Sep 11-29), 2017/02/27 21:36:42]

Done.

+
+ private:
+  friend class chromeos::FingerprintUnlockTestApi;
+
+  PrefService* pref_service_;
+  int unlock_attempt_count_ = 0;
+  bool has_enrollments_ = false;
+  base::Time last_strong_auth_;
+
+  DISALLOW_COPY_AND_ASSIGN(FingerprintUnlock);
+};
+
+}  // namespace quick_unlock
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_QUICK_UNLOCK_FINGERPRINT_UNLOCK_H_