[Sync] Add missing visit to session_id.

components/sync/protocol/proto_visitors.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_SYNC_PROTOCOL_PROTO_VISITORS_H_
 #define COMPONENTS_SYNC_PROTOCOL_PROTO_VISITORS_H_
 
 #include "components/sync/protocol/app_list_specifics.pb.h"
 #include "components/sync/protocol/app_notification_specifics.pb.h"
 #include "components/sync/protocol/app_setting_specifics.pb.h"
@@ skipping 832 matching lines @@
 VISIT_PROTO_FIELDS(const sync_pb::UniquePosition& proto) {
   VISIT_BYTES(value);
   VISIT_BYTES(compressed_value);
   VISIT(uncompressed_length);
   VISIT_BYTES(custom_compressed_v1);
 }
 
 VISIT_PROTO_FIELDS(const sync_pb::UserEventSpecifics& proto) {
   VISIT(event_time_usec);
   VISIT(navigation_id);
+  VISIT(session_id);
 }
 
 VISIT_PROTO_FIELDS(const sync_pb::WalletMaskedCreditCard& proto) {
   VISIT(id);
   VISIT_ENUM(status);
   VISIT(name_on_card);
   VISIT_ENUM(type);
   VISIT(last_four);
   VISIT(exp_month);
   VISIT(exp_year);
@@ skipping 39 matching lines @@
 
 }  // namespace syncer
 
 #undef VISIT_
 #undef VISIT_BYTES
 #undef VISIT_ENUM
 #undef VISIT
 #undef VISIT_REP
 
 #endif  // COMPONENTS_SYNC_PROTOCOL_PROTO_VISITORS_H_