The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02

commit d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02
Author: Mathieu Perreault <mathp@chromium.org>
Date: Wed Oct 18 16:52:17 2017

[Autofill] Provide developer warnings about autocomplete attributes.

Developers are now warned (verbose level) in the DevTools when Autofill has a
suggestion regarding an autocomplete attribute that should be used.

Bug:  773186 
Change-Id: I03d11a3b86f410ca20c34aabbe13819fbc276a17
Reviewed-on: https://chromium-review.googlesource.com/708414
Commit-Queue: Mathieu Perreault <mathp@chromium.org>
Reviewed-by: Roger McFarlane <rogerm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509792}
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/chrome/browser/autofill/form_structure_browsertest.cc
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/chrome/renderer/autofill/form_autofill_browsertest.cc
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/chrome/renderer/autofill/page_passwords_analyser_browsertest.cc
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/components/autofill/content/browser/content_autofill_driver.cc
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/components/autofill/content/browser/content_autofill_driver_unittest.cc
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/components/autofill/content/renderer/BUILD.gn
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/components/autofill/content/renderer/autofill_agent.cc
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/components/autofill/content/renderer/form_cache.cc
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/components/autofill/content/renderer/form_cache.h
[add] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/components/autofill/content/renderer/page_form_analyser_logger.cc
[add] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/components/autofill/content/renderer/page_form_analyser_logger.h
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/components/autofill/content/renderer/page_passwords_analyser.cc
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/components/autofill/content/renderer/page_passwords_analyser.h
[modify] https://crrev.com/d7b56b49ad4e67de3ae359ac1d80c0e0255f5b02/components/autofill/core/browser/autofill_manager.cc

this is generating warnings in Canary for autocomplete="off" whilst linking to the standard which states that autocomplete="off" is a valid attribute

[DOM] Input elements should have autocomplete attributes (suggested: autocomplete='tel', confirm at https://goo.gl/6KgkJg) 

https://bugs.chromium.org/p/chromium/issues/detail?id=587466
https://bugs.chromium.org/p/chromium/issues/detail?id=798709

zac, can you provide a jsbin page which reproduces the warnings you're talking about?

with three form fields the warning is triggered
https://plnkr.co/edit/zCX4EpeaValQGlNVT1Oo?p=preview

but with only two form fields, it's not triggered
https://plnkr.co/edit/tL8Fpiy8b6I39Fb8qbpC?p=preview

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/35dd154a2a497e502e50cd83ced9b16f41995ef4

commit 35dd154a2a497e502e50cd83ced9b16f41995ef4
Author: Dominic Battre <battre@chromium.org>
Date: Wed Nov 21 15:35:01 2018

Replicate autofill data into a different attribute

If you enable chrome://flags/#show-autofill-type-predictions, Chrome will put
information about the autofill state for a specific <input> field into the
field's titel attribute. This is convenient for debugging because you can hover
over the field to read the information. Unfortunately, this is brittle if you
also use Google Translate for the site as Translate will try to translate the
titel value. This breaks automated processing of the data. This CL replicates
the annotations into a second attribute 'autofill-information' that should not
be touched by Google Translate.

Bug:  773186 
Change-Id: I1716b8d78e360ec67f20578cf07444018b989653
Reviewed-on: https://chromium-review.googlesource.com/c/1346050
Commit-Queue: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Reviewed-by: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610066}
[modify] https://crrev.com/35dd154a2a497e502e50cd83ced9b16f41995ef4/components/autofill/content/renderer/form_cache.cc