We need some archival research done on what trigger width Chrome used to hide the close button five years or so ago.  Right we're trying to make it hide when there's not space for it, which seems maybe too late.

From my quick check in Canary, the close button is on non-active tabs when tabs are 132px wide but not at 126px. Looking back at old style, it's there at 142px wide but not at 132px wide.

I checked the source from five years ago.  We always hid close buttons once icon capacity dropped below 3, so that's not better or worse pre-refresh than it was long ago.

We're currently fiddling with a lot of padding and layout stuff inside tabs, so the precise point where close buttons show and hide will change, but I'm reasonably confident that we haven't made any drastic logic changes (yet) here.  I think when measured the way I measure tab width, the two versions are within a few pixels of each other in terms of when close buttons get hidden.

I'll keep an eye on this and make sure we don't regress things by more than that amount at most; in practice I would expect us to hide close buttons sooner than pre-refresh rather than later once we're done fiddling, which ought to make you happy.

Repurposing bug to handle this.

OK... so what is the updated bug covering, then?

Race condition in bug update + bug update.

Marking WontFix per #5.

I actually think the size at which close buttons disappear is way way too small, even before the current UI update. I'm going to address this by increasing the size at which close buttons disappear.

Is this expensive to fix?

Nope, it's in the CQ

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bb53e26734e70a1f28d0d1d3fe16f2a7eaf5ca27

commit bb53e26734e70a1f28d0d1d3fe16f2a7eaf5ca27
Author: Bret Sepulveda <bsep@chromium.org>
Date: Tue Jul 17 22:10:09 2018

Increase size at which close buttons on inactive tabs disappear.

This patch changes the size at which close buttons disappear from being
approximately 48 dips of content area to being a fixed constant. As a
first pass I've set the constant to 68 dips, which feels good to me.

This patch also ties the logic for when to show extra left padding to
the close button visibility, which addresses cases where the favicon
would "twitch" due to the alert indicator appearing.

Bug:  853788 ,  863027 
Change-Id: I681f8b7d530b192f2fd5943436ae16bd93f33fba
Reviewed-on: https://chromium-review.googlesource.com/1125315
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Bret Sepulveda <bsep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575795}
[modify] https://crrev.com/bb53e26734e70a1f28d0d1d3fe16f2a7eaf5ca27/chrome/browser/ui/views/tabs/tab.cc
[modify] https://crrev.com/bb53e26734e70a1f28d0d1d3fe16f2a7eaf5ca27/chrome/browser/ui/views/tabs/tab.h
[modify] https://crrev.com/bb53e26734e70a1f28d0d1d3fe16f2a7eaf5ca27/chrome/browser/ui/views/tabs/tab_strip_unittest.cc
[modify] https://crrev.com/bb53e26734e70a1f28d0d1d3fe16f2a7eaf5ca27/chrome/browser/ui/views/tabs/tab_unittest.cc

Need designer input on the exact size (cc bettes@). Otherwise this is done.

What should the size be?

We're going to stick with 68 dips here.