/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/ is in qml-module-qtwebengine 5.9.5+dfsg-0ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/AlertDialog.qml
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/AuthenticationDialog.qml
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/ColorDialog.qml
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/ConfirmDialog.qml
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/FilePicker.qml
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/Menu.qml
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/MenuItem.qml
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/MenuSeparator.qml
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/MessageBubble.qml
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/PromptDialog.qml
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/ToolTip.qml
/usr/lib/x86_64-linux-gnu/qt5/qml/QtWebEngine/Controls1Delegates/qmldir