Fix for fullscreen toolbar obscuring view

[Pat Rondon <pmr patrondon org>]

Hi,

  I've put a patch for bug #338910 (scrollbar obscured in fullscreen
mode - http://bugzilla.gnome.org/show_bug.cgi?id=338910) on bugzilla.
This also fixes #338871 (Fullscreen toolbar stay on screen when
switching workspace - http://bugzilla.gnome.org/show_bug.cgi?id=338871).
Any feedback would be appreciated.

  Thanks,
    Pat