Componentize //chrome/browser/prefs/tracked.

chrome/browser/prefs/tracked/pref_hash_store.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_H_
-#define CHROME_BROWSER_PREFS_TRACKED_PREF_HASH_STORE_H_
-
-#include "base/memory/scoped_ptr.h"
-
-class HashStoreContents;
-class PrefHashStoreTransaction;
-
-// Holds the configuration and implementation used to calculate and verify
-// preference MACs.
-// TODO(gab): Rename this class as it is no longer a store.
-class PrefHashStore {
- public:
-  virtual ~PrefHashStore() {}
-
-  // Returns a PrefHashStoreTransaction which can be used to perform a series
-  // of operations on the hash store. |storage| MAY be used as the backing store
-  // depending on the implementation. Therefore the HashStoreContents used for
-  // related transactions should correspond to the same underlying data store.
-  virtual scoped_ptr<PrefHashStoreTransaction> BeginTransaction(
-      scoped_ptr<HashStoreContents> storage) = 0;
-};
-
-#endif  // CHROME_BROWSER_PREFS_TRACKED_PREF_HASH_STORE_H_