/usr/include/Swiften/Serializer/PayloadSerializers/ is in libswiften-dev 2.0~beta1+dev47-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/Swiften/Serializer/PayloadSerializers/BlockSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/BodySerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/BytestreamsSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/CapsInfoSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/ChatStateSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/CommandSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/DelaySerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/DeliveryReceiptRequestSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/DeliveryReceiptSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/DiscoInfoSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/DiscoItemsSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/ErrorSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/FormSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/FullPayloadSerializerCollection.h
/usr/include/Swiften/Serializer/PayloadSerializers/IBBSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/InBandRegistrationPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/JingleContentPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/JingleFileTransferDescriptionSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/JingleFileTransferHashSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/JingleFileTransferReceivedSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/JingleIBBTransportPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/JinglePayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/JingleS5BTransportPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/LastSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/MUCAdminPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/MUCDestroyPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/MUCInvitationPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/MUCItemSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/MUCOwnerPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/MUCPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/MUCUserPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/NicknameSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/PrioritySerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/PrivateStorageSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/RawXMLPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/ReplaceSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/ResourceBindSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/RosterItemExchangeSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/RosterSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/S5BProxyRequestSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/SearchPayloadSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/SecurityLabelSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/SecurityLabelsCatalogSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/SoftwareVersionSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/StartSessionSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/StatusSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/StatusShowSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/StorageSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/StreamInitiationFileInfoSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/StreamInitiationSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/SubjectSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/VCardSerializer.h
/usr/include/Swiften/Serializer/PayloadSerializers/VCardUpdateSerializer.h