Reland "presubmit: Don't print comments for missing reviewers."

This is a reland of 276bab4c6e

Fixed to include author on the list of reviewers.

Original change's description:
> presubmit: Don't print comments for missing reviewers.
>
> Don't print owners comments when suggesting missing reviewers,
> as this won't be supported when using Gerrit API.
>
> Change-Id: I644b2f87b58a3c9ece3aa7d107100f3501bd3071
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2607675
> Commit-Queue: Josip Sokcevic <sokcevic@google.com>
> Reviewed-by: Gavin Mak <gavinmak@google.com>
> Reviewed-by: Josip Sokcevic <sokcevic@google.com>
> Auto-Submit: Edward Lesmes <ehmaldonado@chromium.org>

Change-Id: I6dfb2087022ad87595e6cabc50d42a8bdf6311b1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2615918
Auto-Submit: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
Reviewed-by: Josip Sokcevic <sokcevic@google.com>

presubmit_canned_checks.py

@@ -1176,17 +1176,8 @@ def CheckOwners(
 
   owner_email = owner_email or input_api.change.author_email
 
-  finder = input_api.owners_finder(
-      affected_files,
-      input_api.change.RepositoryRoot(),
-      owner_email,
-      reviewers,
-      fopen=open,
-      os_path=input_api.os_path,
-      email_postfix='',
-      disable_color=True,
-      override_files=input_api.change.OriginalOwnersFiles())
-  missing_files = finder.unreviewed_files
+  missing_files = owners_db.files_not_covered_by(
+      affected_files, reviewers.union([owner_email]))
   affects_owners = any('OWNERS' in name for name in missing_files)
 
   if input_api.is_committing:
@@ -1216,15 +1207,9 @@ def CheckOwners(
       output_list.append(output_fn('TBR for OWNERS files are ignored.'))
     if not input_api.is_committing:
       suggested_owners = owners_db.reviewers_for(missing_files, owner_email)
-      owners_with_comments = []
-      def RecordComments(text):
-        owners_with_comments.append(finder.print_indent() + text)
-      finder.writeln = RecordComments
-      for owner in suggested_owners:
-        finder.print_comments(owner)
       output_list.append(output_fn('Suggested OWNERS: ' +
           '(Use "git-cl owners" to interactively select owners.)\n    %s' %
-          ('\n    '.join(owners_with_comments))))
+          ('\n    '.join(suggested_owners))))
     return output_list
 
   if input_api.is_committing and not reviewers:

tests/presubmit_unittest.py

@@ -2721,14 +2721,9 @@ the current line as well!
 
     fake_db = mock.MagicMock(owners.Database)
     fake_db.email_regexp = input_api.re.compile(owners.BASIC_EMAIL_REGEXP)
-    input_api.owners_db = fake_db
+    fake_db.files_not_covered_by.return_value = uncovered_files
 
-    fake_finder = mock.MagicMock(owners_finder.OwnersFinder)
-    fake_finder.unreviewed_files = uncovered_files
-    fake_finder.print_indent = lambda: ''
-    # pylint: disable=unnecessary-lambda
-    fake_finder.print_comments = lambda owner: fake_finder.writeln(owner)
-    input_api.owners_finder = lambda *args, **kwargs: fake_finder
+    input_api.owners_db = fake_db
     input_api.is_committing = is_committing
     input_api.tbr = tbr
     input_api.dry_run = dry_run
@@ -2775,6 +2770,11 @@ the current line as well!
       self.assertRegexpMatches(sys.stdout.getvalue(), expected_output)
     else:
       self.assertEqual(sys.stdout.getvalue(), expected_output)
+
+    files_not_covered_by_calls = fake_db.files_not_covered_by.mock_calls
+    if len(files_not_covered_by_calls):
+      actual_reviewers = fake_db.files_not_covered_by.mock_calls[0][1][1]
+      self.assertIn(change.author_email, actual_reviewers)
     sys.stdout.truncate(0)
 
   def testCannedCheckOwners_DryRun(self):