Componentize //chrome/browser/prefs/tracked.

chrome/browser/prefs/tracked/pref_hash_store_impl.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_STORE_IMPL_H_
-#define CHROME_BROWSER_PREFS_TRACKED_PREF_HASH_STORE_IMPL_H_
-
-#include <string>
-
-#include "base/compiler_specific.h"
-#include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
-#include "chrome/browser/prefs/tracked/pref_hash_calculator.h"
-#include "chrome/browser/prefs/tracked/pref_hash_store.h"
-
-class HashStoreContents;
-class PrefHashStoreTransaction;
-
-// Implements PrefHashStoreImpl by storing preference hashes in a
-// HashStoreContents.
-class PrefHashStoreImpl : public PrefHashStore {
- public:
-  enum StoreVersion {
-    // No hashes have been stored in this PrefHashStore yet.
-    VERSION_UNINITIALIZED = 0,
-    // The hashes in this PrefHashStore were stored before the introduction
-    // of a version number and should be re-initialized.
-    VERSION_PRE_MIGRATION = 1,
-    // The hashes in this PrefHashStore were stored using the latest algorithm.
-    VERSION_LATEST = 2,
-  };
-
-  // Constructs a PrefHashStoreImpl that calculates hashes using
-  // |seed| and |device_id| and stores them in |contents|.
-  //
-  // The same |seed| and |device_id| must be used to load and validate
-  // previously stored hashes in |contents|.
-  PrefHashStoreImpl(const std::string& seed,
-                    const std::string& device_id,
-                    bool use_super_mac);
-
-  ~PrefHashStoreImpl() override;
-
-  // Provides an external HashStoreContents implementation to be used.
-  // BeginTransaction() will ignore |storage| if this is provided.
-  void set_legacy_hash_store_contents(
-      scoped_ptr<HashStoreContents> legacy_hash_store_contents);
-
-  // Clears the contents of this PrefHashStore. |IsInitialized()| will return
-  // false after this call.
-  void Reset();
-
-  // PrefHashStore implementation.
-  scoped_ptr<PrefHashStoreTransaction> BeginTransaction(
-      scoped_ptr<HashStoreContents> storage) override;
-
- private:
-  class PrefHashStoreTransactionImpl;
-
-  const PrefHashCalculator pref_hash_calculator_;
-  scoped_ptr<HashStoreContents> legacy_hash_store_contents_;
-  bool use_super_mac_;
-
-  DISALLOW_COPY_AND_ASSIGN(PrefHashStoreImpl);
-};
-
-#endif  // CHROME_BROWSER_PREFS_TRACKED_PREF_HASH_STORE_IMPL_H_