I introduced the constant here: https://chromium-review.googlesource.com/c/chromium/src/+/1183430

We can use that constant in the meantime, but it'd be best if we could use a constant that has some semantic meaning in Chrome beyond just the Autofill dropdown.

Max, do you know why 24dp was chosen specifically?

Yes, the 24dp spacing ensures that the text labels don't blend into each other visually. Is there a constant that has semantic meaning and is close to 24dp, e.g. 16, 18 or 20dp?

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This proposal LGTM. I really prefer 24.

24 looks great! 

OK, I'll make a one-line change now and leave a TODO to do it "the right way."

crbug.com/876364

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e0c7b3f5332e552632368c52470ca094e3f3ae07

commit e0c7b3f5332e552632368c52470ca094e3f3ae07
Author: Tommy Martino <tmartino@chromium.org>
Date: Wed Aug 22 14:54:13 2018

[Autofill Views] Set spacing to 24px

Per UX request (see bug).
See also screenshots (Googlers only):
https://docs.google.com/presentation/d/1IeyKg22nSbt8aDkvCGrHx1SBg7UBQIqymWDj2sLJ9JQ/edit#slide=id.g3fd38cc212_0_5

Bug: 876291
Change-Id: I8c782d42a5901286ee2c657b7625fbdab4dd62a2
Reviewed-on: https://chromium-review.googlesource.com/1184057
Reviewed-by: Fabio Tirelo <ftirelo@chromium.org>
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Commit-Queue: Tommy Martino <tmartino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585016}
[modify] https://crrev.com/e0c7b3f5332e552632368c52470ca094e3f3ae07/chrome/browser/ui/views/autofill/autofill_popup_base_view.h
[modify] https://crrev.com/e0c7b3f5332e552632368c52470ca094e3f3ae07/chrome/browser/ui/views/autofill/autofill_popup_view_native_views.cc

Tried testing the issue on latest chrome #70.0.3532.0 using Windows 10 by following below steps.
Note : The test URL is taken from issue : 866637 (comment #5)

Steps:
======
1.Launched chrome.
2.Added auto fill details by navigating to chrome://settings/autofill
3.Navigated to the URL  "http://zkoch.github.io/https-things/datalist.html".
4.When clicked on "Given name" text box, observed no difference in spacing between build without fix #70.0.3529.3 and latest chrome #70.0.3532.0

Attached the screenshots for reference.
tmartino@ - Could you please check screenshots and let us know if anything is being missed from our end. Requesting you to help us in verifying the fix.

Thanks.!

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	876291-Without_Fix.png 342 KB View Download

Deleted: 70.0.3432.0.png 442 KB

	70.0.3432.0.png 442 KB View Download

swarnasree.mukkala@: please enable chrome://flags#upcoming-ui-features.

The change only affects the new UI for the Autofill dropdown, which can be enabled by the flag.

Thanks.