Delete the PreferenceMACs on profile deletion.

components/prefs/persistent_pref_store.h

Index: components/prefs/persistent_pref_store.h
diff --git a/components/prefs/persistent_pref_store.h b/components/prefs/persistent_pref_store.h
index 7bc28278be6082009ca5b20f4c00ab459d063ac2..f01595cbc2db2ab19ffa292fad35619fa0dad184 100644
--- a/components/prefs/persistent_pref_store.h
+++ b/components/prefs/persistent_pref_store.h
@@ -73,6 +73,9 @@ class COMPONENTS_PREFS_EXPORT PersistentPrefStore : public WriteablePrefStore {
   // It should be called only for Incognito pref store.
   virtual void ClearMutableValues() = 0;
 
+  // Cleans data stored outside of the profile directory.
+  virtual void CleanupForProfileDeletion() = 0;
+
  protected:
   ~PersistentPrefStore() override {}
 };