add changes to presubmit needed for OWNERS support

presubmit_canned_checks.py

 # Copyright (c) 2010 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."""
 
 ### Description checks
 
 def CheckChangeHasTestField(input_api, output_api):
   """Requires that the changelist have a TEST= field."""
@@ skipping 614 matching lines @@
         long_text='\n'.join(out))]
   return []
 
 
 def CheckOwners(input_api, output_api, source_file_filter=None):
   affected_files = set([f.LocalPath() for f in
       input_api.change.AffectedFiles(source_file_filter)])
   owners_db = input_api.owners_db
 
   if input_api.is_committing:
-    missing_files = owners_db.FilesNotCoveredBy(affected_files,
+    missing_files = owners_db.files_not_covered_by(affected_files,
                                                 input_api.change.approvers)
     if missing_files:
-      return [output_api.PresubmitPromptWarning('Missing approvals for: %s' %
+      return [output_api.PresubmitError('Missing owner LGTM for: %s' %
               ','.join(missing_files))]
     return []
   elif input_api.change.tags.get('R'):
     return []
 
-  suggested_reviewers = owners_db.ReviewersFor(affected_files)
-  # TODO(dpranke): Actually propagate the info back.
-  return []
+  suggested_reviewers = owners_db.reviewers_for(affected_files)
+  return [output_api.PresubmitAddText('R=%s' % ','.join(suggested_reviewers))]