Update the super MAC after performing MAC validation.

chrome/browser/prefs/pref_hash_store_transaction.h

 // Copyright 2014 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_TRANSACTION_H_
 #define CHROME_BROWSER_PREFS_PREF_HASH_STORE_TRANSACTION_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 49 matching lines @@
   virtual ValueState CheckSplitValue(
       const std::string& path,
       const base::DictionaryValue* initial_split_value,
       std::vector<std::string>* invalid_keys) const = 0;
 
   // Stores hashes for the |value| of the split preference at |path|.
   // |split_value| being an empty dictionary or NULL is equivalent.
   virtual void StoreSplitHash(
       const std::string& path,
       const base::DictionaryValue* split_value) = 0;
+
+  // Forces the super MAC to be updated. Returns true if this results in a

[gab, 2014/06/11 21:28:04]

s/updated/set if it's invalid/

+  // change to the store contents.

[gab, 2014/06/11 21:28:04]

s/the store/this store's/

+  virtual bool StampSuperMac() = 0;

[gab, 2014/06/11 21:28:04]

How about SetSuperMacIfRequired() ?

With that name if it feels more natural to me that it may or may not do work and
that it would return a boolean based on whether it did work.

 };
 
 #endif  // CHROME_BROWSER_PREFS_PREF_HASH_STORE_TRANSACTION_H_