Revert of Implement owners check in presubmit for Gerrit.

presubmit_canned_checks.py

Index: presubmit_canned_checks.py
diff --git a/presubmit_canned_checks.py b/presubmit_canned_checks.py
index 1e16d8fffba2a70c69c75de569b37e9b8d0edbd7..e21d08675f27849a0a40a1a580908a36b2826d3e 100644
--- a/presubmit_canned_checks.py
+++ b/presubmit_canned_checks.py
@@ -875,7 +875,8 @@
       input_api.change.AffectedFiles(file_filter=source_file_filter)])
 
   owners_db = input_api.owners_db
-  owner_email, reviewers = _CodereviewOwnersAndReviewers(
+  # TODO(tandrii): this will always return None, set() in case of Gerrit.
+  owner_email, reviewers = _RietveldOwnerAndReviewers(
       input_api,
       owners_db.email_regexp,
       approval_needed=input_api.is_committing)
@@ -904,26 +905,6 @@
     return [output('Missing LGTM from someone other than %s' % owner_email)]
   return []
 
-def _CodereviewOwnersAndReviewers(input_api, email_regexp, approval_needed):
-  """Return the owner and reviewers of a change, if any.
-
-  If approval_needed is True, only reviewers who have approved the change
-  will be returned.
-  """
-  if input_api.change.issue:
-    if input_api.gerrit:
-      res = _GerritOwnerAndReviewers(input_api, email_regexp, approval_needed)
-    else:
-      # Rietveld is default.
-      res = _RietveldOwnerAndReviewers(input_api, email_regexp, approval_needed)
-    if res:
-      return res
-
-  reviewers = set()
-  if not approval_needed:
-    reviewers = _ReviewersFromChange(input_api.change)
-  return None, reviewers
-
 
 def _GetRietveldIssueProps(input_api, messages):
   """Gets the issue properties from rietveld."""
@@ -945,49 +926,33 @@
   return set(reviewer for reviewer in reviewers if '@' in reviewer)
 
 
-def _match_reviewer_email(r, owner_email, email_regexp):
-  return email_regexp.match(r) and r != owner_email
-
 def _RietveldOwnerAndReviewers(input_api, email_regexp, approval_needed=False):
   """Return the owner and reviewers of a change, if any.
 
   If approval_needed is True, only reviewers who have approved the change
   will be returned.
-  Returns None if can't fetch issue properties from codereview.
   """
   issue_props = _GetRietveldIssueProps(input_api, True)
   if not issue_props:
-    return None
+    reviewers = set()
+    if not approval_needed:
+      reviewers = _ReviewersFromChange(input_api.change)
+    return None, reviewers
 
   if not approval_needed:
     return issue_props['owner_email'], set(issue_props['reviewers'])
 
   owner_email = issue_props['owner_email']
+
+  def match_reviewer(r):
+    return email_regexp.match(r) and r != owner_email
 
   messages = issue_props.get('messages', [])
   approvers = set(
       m['sender'] for m in messages
-      if m.get('approval') and _match_reviewer_email(m['sender'], owner_email,
-                                                     email_regexp))
+      if m.get('approval') and match_reviewer(m['sender']))
+
   return owner_email, approvers
-
-
-def _GerritOwnerAndReviewers(input_api, email_regexp, approval_needed=False):
-  """Return the owner and reviewers of a change, if any.
-
-  If approval_needed is True, only reviewers who have approved the change
-  will be returned.
-  Returns None if can't fetch issue properties from codereview.
-  """
-  issue = input_api.change.issue
-  if not issue:
-    return None
-
-  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))
-  return owner_email, reviewers
 
 
 def _CheckConstNSObject(input_api, output_api, source_file_filter):