This is likely for the same reason as 918335. Working on it.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d393ae33a44814e3d54d5d803878c94231091a07

commit d393ae33a44814e3d54d5d803878c94231091a07
Author: Tomasz Wiszkowski <ender@google.com>
Date: Thu Jan 03 19:54:46 2019

Ensure Status view hiding animation is properly started.

Overlooked in crrev/c/1393888

Bug:  918877 , 918335

Change-Id: I4c4f0274eefd0b23d449390699f673e061653b48
Reviewed-on: https://chromium-review.googlesource.com/c/1394784
Commit-Queue: Tomasz Wiszkowski <ender@google.com>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#619726}
[modify] https://crrev.com/d393ae33a44814e3d54d5d803878c94231091a07/chrome/android/java/src/org/chromium/chrome/browser/omnibox/status/StatusView.java

While the situation is improved with that change (e.g. the gap goes away), there is pretty reliable and noticeable jump in the transition of icon -> no icon.

I find it most obvious going from lock icon -> new incognito tab.  The same happens occasionally if I do forward back navigation between a lock icon site and one without (e.g. amazon.com -> chrome://version and then back and forth).

I think in the case where we're transitioning to no icon, we might want to skip any potential animations.  I think the animations can look ok when transitioning between two icons, but otherwise we'd need to build a more robust animation to handle sliding the text around in response to the icon appearing/disappearing.

I see what you mean.

Looks like using TransitionDrawable is trickier than it looked like initially, and without feedback mechanism (~Listener), it will be quite a challenge to get this done right.

I think I'll just use TransitionDrawable for icon changes, but i'll simply fade view in or out when showing/clearing icon instead. I tried a few approaches, but each has its own cases that I yet fail to see.

Thanks for being vigilant! I'll take care of this.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/04dc409ca1d7af5a6b515521db1f3a1049249a54

commit 04dc409ca1d7af5a6b515521db1f3a1049249a54
Author: Tomasz Wiszkowski <ender@google.com>
Date: Fri Jan 04 22:24:42 2019

Fix timing issue when hiding status icon.

Different timing being used by TransitionDrawable and Android Animations
caused a glitch where disappearing padlock icon would leave briefly an empty
space before disappearing the view completely.

This change restores logic that animates in and out the status view when
it is being presented or hidden.

Bug:  918877 
Change-Id: If179cb153d4db4ff71637af6bc68096c8bc147bc
Reviewed-on: https://chromium-review.googlesource.com/c/1395881
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Tomasz Wiszkowski <ender@google.com>
Cr-Commit-Position: refs/heads/master@{#620087}
[modify] https://crrev.com/04dc409ca1d7af5a6b515521db1f3a1049249a54/chrome/android/java/src/org/chromium/chrome/browser/omnibox/status/StatusView.java

Missed this last week. My bad.