Add more debugging in presubmit owners check for Gerrit.

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__))
 
 # Justifications for each filter:
@@ skipping 981 matching lines @@
   """
   issue = input_api.change.issue
   if not issue:
     return None, (set() if approval_needed else
                   _ReviewersFromChange(input_api.change))
 
   owner_email = input_api.gerrit.GetChangeOwner(issue)
   reviewers = set(
       r for r in input_api.gerrit.GetChangeReviewers(issue, approval_needed)
       if _match_reviewer_email(r, owner_email, email_regexp))
+  input_api.logging.debug('owner: %s; approvals given by: %s',
+                          owner_email, ', '.join(sorted(reviewers)))
   return owner_email, reviewers
 
 
 def _CheckConstNSObject(input_api, output_api, source_file_filter):
   """Checks to make sure no objective-c files have |const NSSomeClass*|."""
   pattern = input_api.re.compile(
     r'(?<!reinterpret_cast<)'
     r'const\s+NS(?!(Point|Range|Rect|Size)\s*\*)\w*\s*\*')
 
   def objective_c_filter(f):
@@ skipping 164 matching lines @@
   for f in affected_files:
     cmd = ['gn', 'format', '--dry-run', f.AbsoluteLocalPath()]
     rc = gn.main(cmd)
     if rc == 2:
       warnings.append(output_api.PresubmitPromptWarning(
           '%s requires formatting. Please run:\n  gn format %s' % (
               f.AbsoluteLocalPath(), f.LocalPath())))
   # It's just a warning, so ignore other types of failures assuming they'll be
   # caught elsewhere.
   return warnings