Move preference MACs to the protected preference stores.

chrome/browser/prefs/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_PREF_HASH_STORE_IMPL_H_
 #define CHROME_BROWSER_PREFS_PREF_HASH_STORE_IMPL_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 24 matching lines @@
     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,
-                    scoped_ptr<HashStoreContents> contents,
                     bool use_super_mac);
 
   virtual ~PrefHashStoreImpl();
 
   // Clears the contents of this PrefHashStore. |IsInitialized()| will return
   // false after this call.
   void Reset();
 
   // PrefHashStore implementation.
-  virtual scoped_ptr<PrefHashStoreTransaction> BeginTransaction() OVERRIDE;
-  virtual void CommitPendingWrite() OVERRIDE;
+  virtual scoped_ptr<PrefHashStoreTransaction> BeginTransaction(
+      base::DictionaryValue* storage) OVERRIDE;
 
  private:
   class PrefHashStoreTransactionImpl;
 
   const PrefHashCalculator pref_hash_calculator_;
-  scoped_ptr<HashStoreContents> contents_;
-  const bool initial_hashes_dictionary_trusted_;
   bool use_super_mac_;
 
-  // True if hashes have been modified since the last call to
-  // CommitPendingWriteIfRequired().
-  bool has_pending_write_;
-
   DISALLOW_COPY_AND_ASSIGN(PrefHashStoreImpl);
 };
 
 #endif  // CHROME_BROWSER_PREFS_PREF_HASH_STORE_IMPL_H_