Issue 862990 has been merged into this issue.

Btw, you can skip (1), it's not a necessary step :)
But otherwise Chrome crashes as in issue 862990.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3bb8e0e2f98fa7ac912b0051d452d86a0d1bb27f

commit 3bb8e0e2f98fa7ac912b0051d452d86a0d1bb27f
Author: Peter Boström <pbos@chromium.org>
Date: Thu Jul 12 22:15:32 2018

Don't show the avatar bubble in Incognito

This is a regression in Refresh as the avatar button exists in Incognito
for badging but no avatar bubble should be brought up. The logic
previously depended on the avatar button not existing at all in
Incognito.

The change simply early returns before showing a menu if in Incognito.

Bug:  chromium:863154 
Change-Id: Ifd34b4722f5ecb41d84d376f34a9adf5cf930d06
Reviewed-on: https://chromium-review.googlesource.com/1135722
Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Reviewed-by: Thomas Tangl <tangltom@chromium.org>
Commit-Queue: Peter Boström <pbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574749}
[modify] https://crrev.com/3bb8e0e2f98fa7ac912b0051d452d86a0d1bb27f/chrome/browser/ui/views/frame/browser_view.cc

 Issue 856966  has been merged into this issue.

Able to reproduce the issue on Ubuntu 17.10  on reported chromium version 69.0.3490.0.

Verified the fix on Ubuntu 17.10, Windows 10 and Mac 10.12.6 as per comment#0 on latest chromium version #69.0.3493.0.
Attaching screen shot for reference.
Observed that the user menu cannot be opened in Incognito
Hence, the fix is working as expected.
Adding the verified labels.

Thanks...!!

Deleted: 863154.png 139 KB

	863154.png 139 KB View Download

Thanks!