Gnome 3 - Gedit 3.10 Any Auto session saver plugin?
For Gedit 3.10 (included in Ubuntu 14.04 too) you can use gedit-restore-tabs:
Upon starting Gedit, this plugin will try restore all open documents from the last Gedit window that was closed.
For older versions, you might want to try the reopen-tabs-gedit-plugin:
The plugin is intended to be used by those who uses gedit as a source code editor. It spares you reopening the documents that were loaded last time you closed gedit.