rebaseline.py: add bug-filing URL to error message

R=bsalomon@google.com

Review URL: https://codereview.chromium.org/23968002

git-svn-id: http://skia.googlecode.com/svn/trunk@11133 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tools/rebaseline.py b/tools/rebaseline.py
index a1e3c57..d4edf50 100755
--- a/tools/rebaseline.py
+++ b/tools/rebaseline.py
@@ -121,8 +121,12 @@
       self._failures_encountered.append(exc_info)
     else:
       print >> sys.stderr, (
-          'Halting at first exception; to keep going, re-run ' +
-          'with the --keep-going-on-failure option set.')
+          '\nHalting at first exception.\n' +
+          'Please file a bug to epoger@google.com at ' +
+          'https://code.google.com/p/skia/issues/entry, containing the ' +
+          'command you ran and the following stack trace.\n\n' +
+          'Afterwards, you can re-run with the --keep-going-on-failure ' +
+          'option set.\n')
       raise exc_info[1], None, exc_info[2]
 
   def ReportAllFailures(self):