Add comments describing some more files.

git-svn-id: svn://10.0.0.236/trunk@193306 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/content/base/src/nsGkAtoms.cpp

@@ -34,6 +34,13 @@
  * the terms of any one of the MPL, the GPL or the LGPL.
  *
  * ***** END LICENSE BLOCK ***** */
+
+/*
+ * This class wraps up the creation (and destruction) of the standard
+ * set of atoms used by gklayout; the atoms are created when gklayout
+ * is loaded and they are destroyed when gklayout is unloaded.
+ */
+
 #include "nsGkAtoms.h"
 #include "nsStaticAtom.h"