components/user_prefs/tracked/tracked_preference.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_USER_PREFS_TRACKED_TRACKED_PREFERENCE_H_
   6 #define COMPONENTS_USER_PREFS_TRACKED_TRACKED_PREFERENCE_H_
   7
   8 class PrefHashStoreTransaction;
   9
  10 namespace base {
  11 class DictionaryValue;
  12 class Value;
  13 }
  14
  15 // A TrackedPreference tracks changes to an individual preference, reporting and
  16 // reacting to them according to preference-specific and browser-wide policies.
  17 class TrackedPreference {
  18  public:
  19   virtual ~TrackedPreference() {}
  20
  21   // Notifies the underlying TrackedPreference about its new |value| which
  22   // can update hashes in the corresponding hash store via |transaction|.
  23   virtual void OnNewValue(const base::Value* value,
  24                           PrefHashStoreTransaction* transaction) const = 0;
  25
  26   // Verifies that the value of this TrackedPreference in |pref_store_contents|
  27   // is valid. Responds to verification failures according to
  28   // preference-specific and browser-wide policy and reports results to via UMA.
  29   // May use |transaction| to check/modify hashes in the corresponding hash
  30   // store.
  31   virtual bool EnforceAndReport(
  32       base::DictionaryValue* pref_store_contents,
  33       PrefHashStoreTransaction* transaction) const = 0;
  34 };
  35
  36 #endif  // COMPONENTS_USER_PREFS_TRACKED_TRACKED_PREFERENCE_H_