[Sync] Add ability to save/restore Nigori to SyncEncryptionHandlerImpl

sync/internal_api/debug_info_event_listener.cc

Index: sync/internal_api/debug_info_event_listener.cc
diff --git a/sync/internal_api/debug_info_event_listener.cc b/sync/internal_api/debug_info_event_listener.cc
index 3e7780cbe17b5656a42469e04e1fc60bbbcc018a..c9a51763584362a3df81eae2fd97cb66774e0610 100644
--- a/sync/internal_api/debug_info_event_listener.cc
+++ b/sync/internal_api/debug_info_event_listener.cc
@@ -109,6 +109,10 @@ void DebugInfoEventListener::OnPassphraseTypeChanged(
   CreateAndAddEvent(sync_pb::SyncEnums::PASSPHRASE_TYPE_CHANGED);
 }
 
+void DebugInfoEventListener::OnLocalSetCustomPassphrase(
+    const SyncEncryptionHandler::NigoriState& nigori_state) {
+}
+
 void DebugInfoEventListener::OnActionableError(
     const SyncProtocolError& sync_error) {
   DCHECK(thread_checker_.CalledOnValidThread());