Integrate registry_hash_store_contents with the rest of tracked prefs.

components/user_prefs/tracked/tracked_split_preference.h

Index: components/user_prefs/tracked/tracked_split_preference.h
diff --git a/components/user_prefs/tracked/tracked_split_preference.h b/components/user_prefs/tracked/tracked_split_preference.h
index f2700a4ddabe42378a699f294b0e7105d226dba2..359c8e1f5709c619c66a0dc4556fb037ed237a6c 100644
--- a/components/user_prefs/tracked/tracked_split_preference.h
+++ b/components/user_prefs/tracked/tracked_split_preference.h
@@ -33,10 +33,13 @@ class TrackedSplitPreference : public TrackedPreference {
                          TrackedPreferenceValidationDelegate* delegate);
 
   // TrackedPreference implementation.
+  TrackedPreferenceType GetType() const override;
   void OnNewValue(const base::Value* value,
                   PrefHashStoreTransaction* transaction) const override;
-  bool EnforceAndReport(base::DictionaryValue* pref_store_contents,
-                        PrefHashStoreTransaction* transaction) const override;
+  bool EnforceAndReport(
+      base::DictionaryValue* pref_store_contents,
+      PrefHashStoreTransaction* transaction,
+      PrefHashStoreTransaction* external_validation_transaction) const override;
 
  private:
   const std::string pref_path_;