Componentize //chrome/browser/prefs/tracked.

chrome/browser/prefs/tracked/pref_hash_calculator.h

-// Copyright 2013 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_PREFS_TRACKED_PREF_HASH_CALCULATOR_H_
-#define CHROME_BROWSER_PREFS_TRACKED_PREF_HASH_CALCULATOR_H_
-
-#include <string>
-
-#include "base/basictypes.h"
-
-namespace base {
-class Value;
-}  // namespace base
-
-// Calculates and validates preference value hashes.
-class PrefHashCalculator {
- public:
-  enum ValidationResult {
-    INVALID,
-    VALID,
-    // Valid under a deprecated but as secure algorithm.
-    VALID_SECURE_LEGACY,
-  };
-
-  // Constructs a PrefHashCalculator using |seed| and |device_id|. The same
-  // parameters must be used in order to successfully validate generated hashes.
-  // |device_id| may be empty.
-  PrefHashCalculator(const std::string& seed, const std::string& device_id);
-
-  ~PrefHashCalculator();
-
-  // Calculates a hash value for the supplied preference |path| and |value|.
-  // |value| may be null if the preference has no value.
-  std::string Calculate(const std::string& path, const base::Value* value)
-      const;
-
-  // Validates the provided preference hash using current and legacy hashing
-  // algorithms.
-  ValidationResult Validate(const std::string& path,
-                            const base::Value* value,
-                            const std::string& hash) const;
-
- private:
-  const std::string seed_;
-  const std::string device_id_;
-  const std::string legacy_device_id_;
-
-  DISALLOW_COPY_AND_ASSIGN(PrefHashCalculator);
-};
-
-#endif  // CHROME_BROWSER_PREFS_TRACKED_PREF_HASH_CALCULATOR_H_