Multi-strategy based tracking.

chrome/browser/prefs/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_PREF_HASH_STORE_H_
 #define CHROME_BROWSER_PREFS_PREF_HASH_STORE_H_
 
 #include <string>
-
-#include "base/memory/scoped_ptr.h"
+#include <vector>
 
 namespace base {
+class DictionaryValue;
 class Value;
 }  // namespace base
 
 namespace internals {
 
 // Hash of hashes for each profile, used to validate the existing hashes when
 // debating whether an unknown value is to be trusted, will be stored as a
 // string under
 // |kProfilePreferenceHashes|.|kHashOfHashesPref|.|hash_stored_id_|.
 const char kHashOfHashesPref[] = "hash_of_hashes";
@@ skipping 28 matching lines @@
     TRUSTED_UNKNOWN_VALUE,
   };
 
   // Checks |initial_value| against the existing stored value hash.
   virtual ValueState CheckValue(
       const std::string& path, const base::Value* initial_value) const = 0;
 
   // Stores a hash of the current |value| of the preference at |path|.
   virtual void StoreHash(const std::string& path,
                          const base::Value* value) = 0;
+
+  // Checks |initial_value| against the existing stored hashes for the split
+  // preference at |path|. |initial_split_value| being an empty dictionary or
+  // NULL is equivalent. |invalid_keys| must initially be empty. |invalid_keys|
+  // will not be mofified unless the return value is CHANGED, in which case it
+  // will be filled with the keys that are considered invalid (unknown or
+  // changed).
+  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;
 };
 
 #endif  // CHROME_BROWSER_PREFS_PREF_HASH_STORE_H_