Delete the PreferenceMACs on profile deletion.

components/prefs/overlay_user_pref_store.h

 // Copyright (c) 2012 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 COMPONENTS_PREFS_OVERLAY_USER_PREF_STORE_H_
 #define COMPONENTS_PREFS_OVERLAY_USER_PREF_STORE_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 45 matching lines @@
   PrefReadError GetReadError() const override;
   PrefReadError ReadPrefs() override;
   void ReadPrefsAsync(ReadErrorDelegate* delegate) override;
   void CommitPendingWrite(base::OnceClosure done_callback) override;
   void SchedulePendingLossyWrites() override;
   void ReportValueChanged(const std::string& key, uint32_t flags) override;
 
   void RegisterOverlayPref(const std::string& key);
 
   void ClearMutableValues() override;
+  void OnStoreDeletionFromDisk() override;
 
  protected:
   ~OverlayUserPrefStore() override;
 
  private:
   typedef std::set<std::string> NamesSet;
   class ObserverAdapter;
 
   void OnPrefValueChanged(bool overlay, const std::string& key);
   void OnInitializationCompleted(bool overlay, bool succeeded);
 
   // Returns true if |key| corresponds to a preference that shall be stored in
   // an in-memory PrefStore that is not persisted to disk.
   bool ShallBeStoredInOverlay(const std::string& key) const;
 
   base::ObserverList<PrefStore::Observer, true> observers_;
   std::unique_ptr<ObserverAdapter> overlay_observer_;
   std::unique_ptr<ObserverAdapter> underlay_observer_;
   scoped_refptr<PersistentPrefStore> overlay_;
   scoped_refptr<PersistentPrefStore> underlay_;
   NamesSet overlay_names_set_;
   NamesSet written_overlay_names_;
 
   DISALLOW_COPY_AND_ASSIGN(OverlayUserPrefStore);
 };
 
 #endif  // COMPONENTS_PREFS_OVERLAY_USER_PREF_STORE_H_