Change the "Missing OWNERS" presubmit check to only suggest owners for missing files.

presubmit_canned_checks.py

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generic presubmit checks that can be reused by other presubmit checks."""
 
 import os as _os
 _HERE = _os.path.dirname(_os.path.abspath(__file__))
 
 
@@ skipping 804 matching lines @@
     missing_files = owners_db.files_not_covered_by(affected_files,
         reviewers_plus_owner)
   else:
     missing_files = owners_db.files_not_covered_by(affected_files, reviewers)
 
   if missing_files:
     output_list = [
         output('Missing %s for these files:\n    %s' %
                (needed, '\n    '.join(sorted(missing_files))))]
     if not input_api.is_committing:
-      suggested_owners = owners_db.reviewers_for(affected_files, owner_email)
+      suggested_owners = owners_db.reviewers_for(missing_files, owner_email)
       output_list.append(output('Suggested OWNERS:\n    %s' %
                                 ('\n    '.join(suggested_owners or []))))
     return output_list
 
   if input_api.is_committing and not reviewers:
     return [output('Missing LGTM from someone other than %s' % owner_email)]
   return []
 
 
 def _GetRietveldIssueProps(input_api, messages):
@@ skipping 186 matching lines @@
     snapshot("checking description")
     results.extend(input_api.canned_checks.CheckChangeHasDescription(
         input_api, output_api))
     results.extend(input_api.canned_checks.CheckDoNotSubmitInDescription(
         input_api, output_api))
     snapshot("checking do not submit in files")
     results.extend(input_api.canned_checks.CheckDoNotSubmitInFiles(
         input_api, output_api))
   snapshot("done")
   return results