Are we still going to maintain the autocomplete support anyway?

I think we have to because Autofill only works on Android O and beyond, and will fall back to autocomplete in other Android version.

Or you actually suggest we shouldn't fallback to autocomplete in Android O, and just make autofill not work?

I just wasn't sure what our intention was for the autocomplete code in general. If we're keeping that for older OS versions then I guess using it as a fallback works... though it might be a slightly weird experience for the user to have a different UI/behaviour/set of suggestions in some apps vs others.

Right, UI consistent is a problem, I think we shouldn't fallback to autocomplete in Android O.

I don't know enough about how autocomplete works to really judge here I think, but I would definitely at least consider whether falling back to it is worth it or not for the user, and if there's not some reasonable benefit there, I think it's okay to just declare that these apps won't get either on O and that if they want it to work they shouldn't be using an application context. Up to you/others with more knowledge of the actual experience of autocomplete and autofill here, though :)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/aeb2dd08d7deec2998db3f0c37843cb1103e9954

commit aeb2dd08d7deec2998db3f0c37843cb1103e9954
Author: Tao Bai <michaelbai@chromium.org>
Date: Thu Oct 19 20:29:38 2017

[WebView autofill] Disable the autofill on application context

Android autofill won't work with application context, disable
Autofill if WebView is created with application context.

Also add a warning log.

Bug:  776152 
Change-Id: I3b9b05b43c6359b4f5f4339699b4143b1d0b84ad
Reviewed-on: https://chromium-review.googlesource.com/726968
Reviewed-by: Changwan Ryu <changwan@chromium.org>
Commit-Queue: Tao Bai <michaelbai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#510188}
[modify] https://crrev.com/aeb2dd08d7deec2998db3f0c37843cb1103e9954/android_webview/java/src/org/chromium/android_webview/AwAutofillManager.java