/usr/share/gedit/plugins/snippets/ is in gedit-common 3.18.3-0ubuntu4.
This file is owned by root:root, with mode 0o755.
..
/usr/share/gedit/plugins/snippets/c.xml
/usr/share/gedit/plugins/snippets/chdr.xml
/usr/share/gedit/plugins/snippets/cpp.xml
/usr/share/gedit/plugins/snippets/css.xml
/usr/share/gedit/plugins/snippets/docbook.xml
/usr/share/gedit/plugins/snippets/fortran.xml
/usr/share/gedit/plugins/snippets/global.xml
/usr/share/gedit/plugins/snippets/haskell.xml
/usr/share/gedit/plugins/snippets/html.xml
/usr/share/gedit/plugins/snippets/idl.xml
/usr/share/gedit/plugins/snippets/java.xml
/usr/share/gedit/plugins/snippets/javascript.xml
/usr/share/gedit/plugins/snippets/lang/
/usr/share/gedit/plugins/snippets/lang/snippets.lang
/usr/share/gedit/plugins/snippets/latex.xml
/usr/share/gedit/plugins/snippets/mallard.xml
/usr/share/gedit/plugins/snippets/markdown.xml
/usr/share/gedit/plugins/snippets/perl.xml
/usr/share/gedit/plugins/snippets/php.xml
/usr/share/gedit/plugins/snippets/python.xml
/usr/share/gedit/plugins/snippets/rpmspec.xml
/usr/share/gedit/plugins/snippets/ruby.xml
/usr/share/gedit/plugins/snippets/sh.xml
/usr/share/gedit/plugins/snippets/snippets.xml
/usr/share/gedit/plugins/snippets/tcl.xml
/usr/share/gedit/plugins/snippets/ui/
/usr/share/gedit/plugins/snippets/ui/snippets.ui
/usr/share/gedit/plugins/snippets/xml.xml
/usr/share/gedit/plugins/snippets/xslt.xml