Patch for this is here: https://chromium-review.googlesource.com/c/chromium/src/+/1112587 .

As I'm OOO I won't be able to finish it. I'm passing this to Mike as James is already working on a KSV related stuff.

 Issue 856811  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/086094c1415442a55b6a845553075cf354906a87

commit 086094c1415442a55b6a845553075cf354906a87
Author: Mike Wasserman <msw@chromium.org>
Date: Thu Jun 28 22:25:16 2018

ws: Wire up property for showing top-level window titles

Plumb views::WidgetDelegate::ShouldShowWindowTitle to the ws host frame.
Move prop to aura/client for MusClient and DesktopWindowTreeHostMus.
Make the KSV's delegate return false for ShouldShowWindowTitle.

Based on Scott's CL (PS1 matches crrev.com/c/1112587 PS4)

BUG= 854324 
TEST=covered by tests; No title in Chrome OS KSV (Ctrl-Alt-/)

Change-Id: I190c8245edbb310a1f03f6ec6ad318b325be04bc
Reviewed-on: https://chromium-review.googlesource.com/1113938
Commit-Queue: Michael Wasserman <msw@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571300}
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ash/components/shortcut_viewer/views/keyboard_shortcut_view.cc
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ash/components/shortcut_viewer/views/keyboard_shortcut_view.h
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ash/public/cpp/mus_property_mirror_ash.cc
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ash/public/cpp/window_properties.cc
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ash/public/cpp/window_properties.h
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ash/wm/non_client_frame_controller.cc
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ash/wm/non_client_frame_controller_unittest.cc
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/chrome/browser/ui/views/frame/browser_frame_mash.cc
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ui/aura/client/aura_constants.cc
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ui/aura/client/aura_constants.h
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ui/views/bubble/bubble_frame_view.cc
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ui/views/mus/desktop_window_tree_host_mus.cc
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ui/views/mus/desktop_window_tree_host_mus_unittest.cc
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ui/views/mus/mus_client.cc
[modify] https://crrev.com/086094c1415442a55b6a845553075cf354906a87/ui/views/window/dialog_delegate_unittest.cc