[Sync] Implement EstimateMemoryUsage for SharedModelTypeProcessor and ModelTypeWorker

components/sync/protocol/proto_visitors.h

Index: components/sync/protocol/proto_visitors.h
diff --git a/components/sync/protocol/proto_visitors.h b/components/sync/protocol/proto_visitors.h
index 3aa673e0d03573132ec91c378174b2ea9c79b2fe..56175cf6dbc64c57f49ebd586170916552e61cf1 100644
--- a/components/sync/protocol/proto_visitors.h
+++ b/components/sync/protocol/proto_visitors.h
@@ -21,6 +21,7 @@
 #include "components/sync/protocol/favicon_image_specifics.pb.h"
 #include "components/sync/protocol/favicon_tracking_specifics.pb.h"
 #include "components/sync/protocol/history_delete_directive_specifics.pb.h"
+#include "components/sync/protocol/model_type_state.pb.h"
 #include "components/sync/protocol/nigori_specifics.pb.h"
 #include "components/sync/protocol/password_specifics.pb.h"
 #include "components/sync/protocol/preference_specifics.pb.h"
@@ -859,6 +860,13 @@ VISIT_PROTO_FIELDS(const sync_pb::AttachmentMetadata& proto) {
   VISIT_REP(record);
 }
 
+VISIT_PROTO_FIELDS(const sync_pb::ModelTypeState& proto) {
+  VISIT(progress_marker);
+  VISIT(type_context);
+  VISIT(encryption_key_name);
+  VISIT(initial_sync_done);
+}
+
 VISIT_PROTO_FIELDS(const sync_pb::EntityMetadata& proto) {
   VISIT(client_tag_hash);
   VISIT(server_id);