Working on a CL at https://chromium-review.googlesource.com/c/chromium/src/+/1129847 that shifts the dropdown up and right if it goes off screen (technically past the top of the shelf). Screenshot attached.

Deleted: Screenshot from 2018-07-09 12-37-47.png 90.3 KB

	Screenshot from 2018-07-09 12-37-47.png 90.3 KB View Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1112e023de45107107f178257a5193e0bfa4e92f

commit 1112e023de45107107f178257a5193e0bfa4e92f
Author: Quan Nguyen <qnnguyen@chromium.org>
Date: Mon Jul 09 22:15:20 2018

Move user menu back into the work area if it extends too far down.

Also shifts the user menu right in this case so that the dropdown arrow
remains visible.

Bug:  861791 
Change-Id: I65b0be969c1f15936ce3b86df5bae4eb7c200ed6
Reviewed-on: https://chromium-review.googlesource.com/1129847
Reviewed-by: Jacob Dufault <jdufault@chromium.org>
Commit-Queue: Quan Nguyen <qnnguyen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#573482}
[modify] https://crrev.com/1112e023de45107107f178257a5193e0bfa4e92f/ash/login/ui/login_bubble.cc

This is either not fixed or has since been regressed. The remove user widget is still rendering off-screen, and the "Remove User" button that should be visible is not. This was true for both the official 70.x and now 71.0.3578.94 builds.