Fix components/password_manager/public/interfaces/OWNERS

When some Mojo-related OWNERS rules are not added where they should be,
the _CheckIpcOwners check suggests to add what is missing. The output of
that check is vague about what lines are supposed to go into OWNERS.

This way, components/password_manager/public/interfaces/OWNERS got
extended with some garbage text. [1]

This CL removes that text and also improves a little the presubmit
message, which now says how many of the following lines should be added
to the OWNERS file, as well as moves those lines to the very end of
the whole message.

Adding NOPRESUBMIT because the OWNERS syntax check fails on the old
OWNERS file (which this CL is fixing). This is a known issue and was
discussed on the associated bug. The resolution is that since
presubmit should avoid landing a malformed OWNERS in the future, it
is no problem if it fires for old OWNERS.
NOPRESUBMIT=true

[1] https://chromium-review.googlesource.com/c/chromium/src/+/840381/14/components/password_manager/public/interfaces/OWNERS#8

Bug: 836032
Change-Id: I0c6bdc321de06925d06775a5f1bd034c6c4dc957
Reviewed-on: https://chromium-review.googlesource.com/1025093
Commit-Queue: Vaclav Brozek <[email protected]>
Reviewed-by: Dirk Pranke <[email protected]>
Cr-Commit-Position: refs/heads/master@{#553461}
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 11a05962..77cb7fa9 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -1953,8 +1953,10 @@
       files.extend(['  %s' % f.LocalPath() for f in entry['files']])
     if missing_lines:
       errors.append(
-          '%s needs the following lines added:\n\n%s\n\nfor files:\n%s' %
-          (owners_file, '\n'.join(missing_lines), '\n'.join(files)))
+          'Because of the presence of files:\n%s\n\n'
+          '%s needs the following %d lines added:\n\n%s' %
+          ('\n'.join(files), owners_file, len(missing_lines),
+           '\n'.join(missing_lines)))
 
   results = []
   if errors: