I think this is the same issue as when the browser is active and closed the keyboard persists?

For the purposes of making this a solving bug, adding the following interpreted repro steps:

1: open a folder
2: tap the name field
3: press the 'enter' key on the vkeyboard

expected:
both keyboard and folder close
actual:
only the folder closes

video:
https://photos.app.goo.gl/B2rCiHT4AkFoa8y36

Hitting the enter key in the folder name field should close a folder?

+Ux.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/db6e880b79eed205babfcb2f5d0d5147f441afb4

commit db6e880b79eed205babfcb2f5d0d5147f441afb4
Author: Kevin Strohbehn <ginko@google.com>
Date: Sat Sep 08 01:36:45 2018

Navigate Back closes keyboard if open first, before closing folder

Bug:  878163 
Change-Id: I3e01dacba1cd86753b996d0a55aeefe878dc37f6
Reviewed-on: https://chromium-review.googlesource.com/1213708
Commit-Queue: Kevin Strohbehn <ginko@google.com>
Reviewed-by: Weidong Guo <weidongg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589749}
[modify] https://crrev.com/db6e880b79eed205babfcb2f5d0d5147f441afb4/ash/app_list/views/app_list_folder_view.cc
[modify] https://crrev.com/db6e880b79eed205babfcb2f5d0d5147f441afb4/ash/app_list/views/contents_view.cc
[modify] https://crrev.com/db6e880b79eed205babfcb2f5d0d5147f441afb4/ash/app_list/views/folder_header_view.cc
[modify] https://crrev.com/db6e880b79eed205babfcb2f5d0d5147f441afb4/ash/app_list/views/folder_header_view.h

Issue 773915 has been merged into this issue.