[Sync] Add history delete directive type

sync/util/cryptographer.cc

Index: sync/util/cryptographer.cc
diff --git a/sync/util/cryptographer.cc b/sync/util/cryptographer.cc
index c512ab6bf24c7c10a80b166c9b96ec8367b675da..142d065e20a4bd9e525594ac74963d2223dd2ce0 100644
--- a/sync/util/cryptographer.cc
+++ b/sync/util/cryptographer.cc
@@ -399,6 +399,8 @@ void Cryptographer::UpdateEncryptedTypesFromNigori(
     encrypted_types.Put(APPS);
   if (nigori.encrypt_app_notifications())
     encrypted_types.Put(APP_NOTIFICATIONS);
+  if (nigori.encrypt_history_delete_directives())
+    encrypted_types.Put(HISTORY_DELETE_DIRECTIVES);
 
   // Note: the initial version with encryption did not support the
   // encrypt_everything field. If anything more than the sensitive types were
@@ -437,6 +439,8 @@ void Cryptographer::UpdateNigoriFromEncryptedTypes(
   nigori->set_encrypt_apps(encrypted_types_.Has(APPS));
   nigori->set_encrypt_app_notifications(
       encrypted_types_.Has(APP_NOTIFICATIONS));
+  nigori->set_encrypt_history_delete_directives(
+      encrypted_types_.Has(HISTORY_DELETE_DIRECTIVES));
 }
 
 void Cryptographer::set_encrypt_everything() {