Hook up the presubmit check for empty descriptions.

PRESUBMIT.py

Index: PRESUBMIT.py
===================================================================
--- PRESUBMIT.py	(revision 112749)
+++ PRESUBMIT.py	(working copy)
@@ -324,6 +324,8 @@
       input_api, output_api))
   results.extend(input_api.canned_checks.CheckChangeHasTestField(
       input_api, output_api))
+  results.extend(input_api.canned_checks.CheckChangeHasDescription(

[M-A Ruel, 2011/12/06 01:56:12]

In fact, it's kind of pointless because the two checks above should fire anyway
on an empty description. So in any case, the dude bypassed presubmit checks.

[Lei Zhang, 2011/12/06 02:08:45]

The two tests above only results in a warning on commit. This one results in an
error.

+      input_api, output_api))
   results.extend(_CheckSubversionConfig(input_api, output_api))
   return results