dschuyler@, is this in your current area?

I think what you're seeing is a result of 
https://cs.chromium.org/chromium/src/components/omnibox/browser/omnibox_popup_model.cc?type=cs&q=components/omnibox/browser/omnibox_popup_model.cc&sq=package:chromium&l=89

Which decides not to show the second part if there's not enough space. Though what is 'enough space' seems a matter of opinion. This is in the area I've been working, but it's not something that has changed recently (it's been like this 3+ years). So this is currently working as intended. 

It does look like #omnibox-ui-swap-title-and-url is enabled. Is the concern specifically for the URL? (without that flag, it's the title that would be dropped).

patricialor@, would you like the behavior to change?
Can you help me understand more on whether this is an aesthetic concern or a security concern or a11y concern or something else?

Ah, yep - so not showing the second part (whether it be title / URL) when there's not enough space is fine. It's when you resize it, and the elision. When you reduce the width by some small number of pixels, it disappears (that's fine). But when you reduce it a little bit more, it reappears (without the elision, which seems broken). Reducing the width a little more after that makes it disappear again, then a reducing more makes it reappear again without the elision, and that repeats until there is *actually* no more space to fit the second part of the text - that part seems like a bug to me.

#3 Got it, thanks!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0c73f82b3528047fab41c826799b1a9ac479563e

commit 0c73f82b3528047fab41c826799b1a9ac479563e
Author: Dave Schuyler <dschuyler@chromium.org>
Date: Tue May 08 18:38:08 2018

[Omnibox] update separator width when calculating max widths

This CL updates the size of the separator text when laying out a split
row using ComputeMaxWidths.

Bug:  839714 
Change-Id: I4350f864115bd891a00f3fb8a34a2a2eafe67e17
Reviewed-on: https://chromium-review.googlesource.com/1049106
Commit-Queue: Dave Schuyler <dschuyler@chromium.org>
Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556893}
[modify] https://crrev.com/0c73f82b3528047fab41c826799b1a9ac479563e/chrome/browser/ui/views/omnibox/omnibox_match_cell_view.cc

Unable to reproduce the issue on chrome reported version 68.0.3419.0 using Windows 10 with steps mentioned below:
1) Launched chrome reported version not in maximised mode navigate to URL: https://www.nytimes.com/ and clicked on 'Tech' link
2) Opened new tab and typed 'tec' on omnibar, shows autocomplete results as 'Technology - The New York Times - nytimes.com/section/technology...'
3) Reduced the width of the window until the link('- nytimes.com/section/technology...') disappears, only on resizing the window the URL appears and disappears
4) clicked on tab, NYT URL got focused, hovered the mouse over the link, didn't any flash/appear(or) disappear of link

@Dave Schuyler: Please find the attached screencast for your reference and let us know if we missed anything in reproducing the issue and help us in verifying the fix.

Thanks!

#9, #10 move the window edge (change the size) much slower, right where the url appears/disappears. I *think* I saw it happen in the video at #10, but it's hard to see at the speed with window is changing size.