The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/40d2d2c96d1e739f06c5c096eed5b9bb91a0ea51

commit 40d2d2c96d1e739f06c5c096eed5b9bb91a0ea51
Author: Tim Sergeant <tsergeant@chromium.org>
Date: Thu Jul 20 01:37:06 2017

MD Bookmarks: Use Command rather than Ctrl as a modifier on Mac

It is now possible to command-click to select multiple items, and to use
command+up/down/space to navigate through the bookmark list. The existing
shortcut for opening bookmarks with command-down has been removed to
allow for this.

Bug:  745040 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Ic37d271e04625aac540af778cf84528131b1787c
Reviewed-on: https://chromium-review.googlesource.com/575792
Reviewed-by: calamity <calamity@chromium.org>
Commit-Queue: Tim Sergeant <tsergeant@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488084}
[modify] https://crrev.com/40d2d2c96d1e739f06c5c096eed5b9bb91a0ea51/chrome/browser/resources/md_bookmarks/command_manager.js
[modify] https://crrev.com/40d2d2c96d1e739f06c5c096eed5b9bb91a0ea51/chrome/browser/resources/md_bookmarks/item.js
[modify] https://crrev.com/40d2d2c96d1e739f06c5c096eed5b9bb91a0ea51/chrome/browser/resources/md_bookmarks/list.js
[modify] https://crrev.com/40d2d2c96d1e739f06c5c096eed5b9bb91a0ea51/chrome/test/data/webui/md_bookmarks/command_manager_test.js
[modify] https://crrev.com/40d2d2c96d1e739f06c5c096eed5b9bb91a0ea51/chrome/test/data/webui/md_bookmarks/md_bookmarks_focus_test.js
[modify] https://crrev.com/40d2d2c96d1e739f06c5c096eed5b9bb91a0ea51/chrome/test/data/webui/md_bookmarks/test_util.js