The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ac50b1fbfb0868eadf9eb2c30325ef4c5f7bfce4

commit ac50b1fbfb0868eadf9eb2c30325ef4c5f7bfce4
Author: Alex Newcomer <newcomer@chromium.org>
Date: Fri May 25 23:37:07 2018

cros: Make wallpaper and shelf body use touchable app context menus

Add touchable run types and anchor positions for desktop
menus and menus on the shelf body (|!for_item|).

Bug:  832847 
Change-Id: I788dee1c7a74dc443306ef5af79b463f9472a200
Reviewed-on: https://chromium-review.googlesource.com/1073669
Commit-Queue: Alex Newcomer <newcomer@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562064}
[modify] https://crrev.com/ac50b1fbfb0868eadf9eb2c30325ef4c5f7bfce4/ash/root_window_controller.cc
[modify] https://crrev.com/ac50b1fbfb0868eadf9eb2c30325ef4c5f7bfce4/ash/shelf/shelf_view.cc