Purpose: helper function, just colocates some replicated code to modify the canvas size if there is variation when windows or modes are switched. $LastChangedBy: jimm $ $LastChangedDate: 2014-02-11 10:54:32 -0800 (Tue, 11 Feb 2014) $ $LastChangedRevision: 14326 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/spedas/gui/display/spd_ui_orientation_update.pro $