/usr/share/gedit/plugins/ is in gedit-common 3.4.1-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/gedit/plugins/changecase/
/usr/share/gedit/plugins/externaltools/
/usr/share/gedit/plugins/externaltools/tools/
/usr/share/gedit/plugins/externaltools/tools/build
/usr/share/gedit/plugins/externaltools/tools/open-terminal-here
/usr/share/gedit/plugins/externaltools/tools/remove-trailing-spaces
/usr/share/gedit/plugins/externaltools/tools/run-command
/usr/share/gedit/plugins/externaltools/ui/
/usr/share/gedit/plugins/externaltools/ui/outputpanel.ui
/usr/share/gedit/plugins/externaltools/ui/tools.ui
/usr/share/gedit/plugins/modelines/
/usr/share/gedit/plugins/modelines/language-mappings
/usr/share/gedit/plugins/pythonconsole/
/usr/share/gedit/plugins/pythonconsole/ui/
/usr/share/gedit/plugins/pythonconsole/ui/config.ui
/usr/share/gedit/plugins/snippets/
/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/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