The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b9a79669128060b6b4c184efeabf7a187fef6de3

commit b9a79669128060b6b4c184efeabf7a187fef6de3
Author: Alex Newcomer <newcomer@chromium.org>
Date: Thu Aug 02 23:55:09 2018

cros: Add icons to wallpaper context menus

Three changes:
 - Add the icons for desktop context menu options.
 - Make the "Autohide Shelf" option a regular menu option.
   - This is because touchable menu items do not use the "check" type
     and was OKed by UX.
 - Remove the "Autohide" and "Shelf position" items in tablet mode.
   - This is requested by UX.

Bug:  850134 
Change-Id: I4bc7912687fbd8f1c3543301be511ac02277a859
Reviewed-on: https://chromium-review.googlesource.com/1159735
Commit-Queue: Alex Newcomer <newcomer@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580379}
[modify] https://crrev.com/b9a79669128060b6b4c184efeabf7a187fef6de3/ash/resources/vector_icons/BUILD.gn
[add] https://crrev.com/b9a79669128060b6b4c184efeabf7a187fef6de3/ash/resources/vector_icons/auto_hide.icon
[add] https://crrev.com/b9a79669128060b6b4c184efeabf7a187fef6de3/ash/resources/vector_icons/shelf_position.icon
[add] https://crrev.com/b9a79669128060b6b4c184efeabf7a187fef6de3/ash/resources/vector_icons/wallpaper.icon
[modify] https://crrev.com/b9a79669128060b6b4c184efeabf7a187fef6de3/ash/shelf/shelf_context_menu_model.cc