/usr/include/libgladeui-1.0/gladeui/ is in libgladeui-1-dev 3.8.0-0ubuntu6.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libgladeui-1.0/gladeui/glade-accels.h
/usr/include/libgladeui-1.0/gladeui/glade-activatable-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-app.h
/usr/include/libgladeui-1.0/gladeui/glade-attributes.h
/usr/include/libgladeui-1.0/gladeui/glade-base-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-builtins.h
/usr/include/libgladeui-1.0/gladeui/glade-button-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-catalog.h
/usr/include/libgladeui-1.0/gladeui/glade-cell-renderer-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-cell-renderer-icon.h
/usr/include/libgladeui-1.0/gladeui/glade-clipboard.h
/usr/include/libgladeui-1.0/gladeui/glade-column-types.h
/usr/include/libgladeui-1.0/gladeui/glade-command.h
/usr/include/libgladeui-1.0/gladeui/glade-cursor.h
/usr/include/libgladeui-1.0/gladeui/glade-custom.h
/usr/include/libgladeui-1.0/gladeui/glade-debug.h
/usr/include/libgladeui-1.0/gladeui/glade-design-layout.h
/usr/include/libgladeui-1.0/gladeui/glade-design-view.h
/usr/include/libgladeui-1.0/gladeui/glade-displayable-values.h
/usr/include/libgladeui-1.0/gladeui/glade-editable.h
/usr/include/libgladeui-1.0/gladeui/glade-editor-property.h
/usr/include/libgladeui-1.0/gladeui/glade-editor-table.h
/usr/include/libgladeui-1.0/gladeui/glade-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-entry-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-fixed.h
/usr/include/libgladeui-1.0/gladeui/glade-gtk.h
/usr/include/libgladeui-1.0/gladeui/glade-icon-factory-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-icon-sources.h
/usr/include/libgladeui-1.0/gladeui/glade-image-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-image-item-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-inspector.h
/usr/include/libgladeui-1.0/gladeui/glade-label-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-model-data.h
/usr/include/libgladeui-1.0/gladeui/glade-name-context.h
/usr/include/libgladeui-1.0/gladeui/glade-palette.h
/usr/include/libgladeui-1.0/gladeui/glade-parameter.h
/usr/include/libgladeui-1.0/gladeui/glade-placeholder.h
/usr/include/libgladeui-1.0/gladeui/glade-project.h
/usr/include/libgladeui-1.0/gladeui/glade-property-class.h
/usr/include/libgladeui-1.0/gladeui/glade-property.h
/usr/include/libgladeui-1.0/gladeui/glade-signal-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-signal.h
/usr/include/libgladeui-1.0/gladeui/glade-store-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-text-button.h
/usr/include/libgladeui-1.0/gladeui/glade-tool-button-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-tool-item-group-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-treeview-editor.h
/usr/include/libgladeui-1.0/gladeui/glade-utils.h
/usr/include/libgladeui-1.0/gladeui/glade-widget-action.h
/usr/include/libgladeui-1.0/gladeui/glade-widget-adaptor.h
/usr/include/libgladeui-1.0/gladeui/glade-widget.h
/usr/include/libgladeui-1.0/gladeui/glade-xml-utils.h
/usr/include/libgladeui-1.0/gladeui/glade.h