This was probably introduced with one of my or pbos@'s changes to the AvatarToolbarButton.

I just tested it on my machine. It's reproducible, but as soon as the I click the icon, it changes back. So it's probably a missing-observer issue.
I'll look into it.

Eli, how severe is this issue? I prioritized it with 2 for now.

For what it's worth, I can't reproduce this with Unity turned on.

I would view this as P2. As long as the picture eventually resets to the local avatar, that should be sufficient.

For those who are able to reproduce it: does the picture go away if you open a new tab and navigate somewhere? Or does it only go away if you click the avatar button?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c2f5b2df7f21c1bc0d41ce0e0d929c2ef193e002

commit c2f5b2df7f21c1bc0d41ce0e0d929c2ef193e002
Author: Thomas Tangl <tangltom@chromium.org>
Date: Wed Aug 22 17:49:35 2018

Update avatar toolbar button when account is removed

Update the icon of the avatar toolbar button when
an account is signed out.
This happens for instance when the user selects cancel
on the sync-confirmation dialog.

Bug:  870656 
Change-Id: Id557500c02ef2ac10d704cde75a9afe9db5e7655
Reviewed-on: https://chromium-review.googlesource.com/1185195
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Commit-Queue: Thomas Tangl <tangltom@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585148}
[modify] https://crrev.com/c2f5b2df7f21c1bc0d41ce0e0d929c2ef193e002/chrome/browser/ui/views/profiles/avatar_toolbar_button.cc
[modify] https://crrev.com/c2f5b2df7f21c1bc0d41ce0e0d929c2ef193e002/chrome/browser/ui/views/profiles/avatar_toolbar_button.h

I was a bit late on this, but should we merge this back?
From my perspective this would be totally okay since it's a very trivial change (5 lines), just listening for Account removals and updating the icon in this case.

Without your change, when does the avatar revert back? Is it only when you click on the button, or does it change back eventually by itself (e.g. if you open a new tab or navigate somewhere else)?

FWIW, I don't view this as P1, so I think it's fine to let the fix roll out in 70.

It only reverts back when you click on the button or go to chrome://settings.

However, I just checked and the only way this can happen is when the user selects "Cancel" on the sync confirmation dialog. And I can't reproduce this on Mac.

This means if we are fine that for some users on Linux and Windows this happens, we can let the fix roll out in 70.

Does it get fixed when Chrome gets restarted?

As long as it gets fixed on restart, I don't think this is worth a merge back.

Yes, restart fixes it too. Okay, then it'll be in 70.

Update:
Rechecked the above issue on Win(7,8,8.1,10) ,Mac(10.12.6 , 10.13.1 , 10.13.6, 10.14)  and Linux(14.04 LTS)  OS using latest canary build#70.0.3532.0 and issue is fix. Users GAIA picture disappears from toolbar when user cancels the browser sign in.

Please refer attached screencast for reference.

Thank You...

Deleted: Canary Behaviour.mp4 418 KB

	Canary Behaviour.mp4 418 KB View Download

Perfect. WAI :)