Move preference MACs to the protected preference stores.

base/prefs/persistent_pref_store.h

Index: base/prefs/persistent_pref_store.h
diff --git a/base/prefs/persistent_pref_store.h b/base/prefs/persistent_pref_store.h
index 11d2a54dcc0fb329c634128863e943a87fc07544..fb9d6dcdab62db50801c313ff0629fa86097ba03 100644
--- a/base/prefs/persistent_pref_store.h
+++ b/base/prefs/persistent_pref_store.h
@@ -46,16 +46,6 @@ class BASE_PREFS_EXPORT PersistentPrefStore : public WriteablePrefStore {
     virtual void OnError(PrefReadError error) = 0;
   };
 
-  // Equivalent to PrefStore::GetValue but returns a mutable value.
-  virtual bool GetMutableValue(const std::string& key,
-                               base::Value** result) = 0;
-
-  // Triggers a value changed notification. This function needs to be called
-  // if one retrieves a list or dictionary with GetMutableValue and change its
-  // value. SetValue takes care of notifications itself. Note that
-  // ReportValueChanged will trigger notifications even if nothing has changed.
-  virtual void ReportValueChanged(const std::string& key) = 0;
-
   // Same as SetValue, but doesn't generate notifications. This is used by
   // PrefService::GetMutableUserPref() in order to put empty entries
   // into the user pref store. Using SetValue is not an option since existing