It seems that currently we don't call the developerPrivate API at all, once the user changes the dropdown value.

The old code has been deleted, but you can see the logic at [1] line 386. Or you can revert a local branch before commit 7c7ed7b5507815c694d4c52e85c133be933b93fd to see the previous code.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/954605/11/chrome/browser/resources/extensions/extension_command_list.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b41c63db5b5efa88c4205225cd329a44a18b3492

commit b41c63db5b5efa88c4205225cd329a44a18b3492
Author: Esmael El-Moslimany <aee@chromium.org>
Date: Fri Apr 27 23:04:27 2018

MD Extensions: save changes to shortcut scope

Bug:  836988 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I9d8123653fd77bc9142459d666a0e9697569cd94
Reviewed-on: https://chromium-review.googlesource.com/1029127
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: Esmael El-Moslimany <aee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#554549}
[modify] https://crrev.com/b41c63db5b5efa88c4205225cd329a44a18b3492/chrome/browser/resources/md_extensions/keyboard_shortcuts.js
[modify] https://crrev.com/b41c63db5b5efa88c4205225cd329a44a18b3492/chrome/browser/resources/md_extensions/manager.js
[modify] https://crrev.com/b41c63db5b5efa88c4205225cd329a44a18b3492/chrome/browser/resources/md_extensions/service.js
[modify] https://crrev.com/b41c63db5b5efa88c4205225cd329a44a18b3492/chrome/browser/resources/md_extensions/shortcut_input.js
[modify] https://crrev.com/b41c63db5b5efa88c4205225cd329a44a18b3492/chrome/test/data/webui/extensions/cr_extensions_browsertest.js
[modify] https://crrev.com/b41c63db5b5efa88c4205225cd329a44a18b3492/chrome/test/data/webui/extensions/extension_keyboard_shortcuts_test.js
[modify] https://crrev.com/b41c63db5b5efa88c4205225cd329a44a18b3492/chrome/test/data/webui/extensions/extension_shortcut_input_test.js
[modify] https://crrev.com/b41c63db5b5efa88c4205225cd329a44a18b3492/chrome/test/data/webui/extensions/test_service.js

Should we request a merge to the M67 branch?

I would vote yes. This is a regression from the old UI, and was mentioned as one of the  top user issues (though by no means *the* top).

+1, let's attempt to merge.

This bug requires manual review: M67 has already been promoted to the beta branch, so this requires manual review
Please contact the milestone owner if you have questions.
Owners: cmasso@(Android), cmasso@(iOS), kbleicher@(ChromeOS), govind@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Before we approve merge to M67, please answer followings:
* Is this M67 regression? Is it critical?
* Is the change well baked/verified in Canary, having enough automation tests coverage and safe to merge to M67?
* Any other important details to justify the merge.

Please note M67 is already in Beta, so merge bar is very high. Thank you.

> Is this M67 regression?

This regressed in M65, when the new Extensions UI was rolled out and went unnoticed until now.

> Is it critical?

It was one of the top user-reported issues of last week according to feedback reports.

> Is the change well baked/verified in Canary, having enough automation tests coverage and safe to merge to M67?

The CL that fixed it includes automated tests. Having said that, @aee/@jawag can you verify this works on Canary?

Thank you dpapad@.

I will wait for @aee/@jawag to verify the bug on canary before M67 merge approval.

This is fixed in the canary build. But it uncovered another issue. We are removing the command, then adding it back when we update the scope. This causes a remove event then an add event to be sent to the UI. It's possible for the remove event to be handled after the add event which results in the command looking like it was cleared. I have a CL to fix this issue.

https://chromium-review.googlesource.com/c/chromium/src/+/1036199

Based on comment #13, we also need a merge for - https://chromium-review.googlesource.com/c/chromium/src/+/1036199 to M67 along with cl listed at #3?  If yes, it is really worth and safe to take multiple merges for the regression which has been exists since M65?

I think we should hold off on merging this given the outstanding issue noted in comment #13.

Thank you  aee@. Rejecting merge to M67 based on comment #15.

SGTM - I think the user report volumes were small enough that we can wait until M68 for this.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/19f16a5138c95e212161ecfeb1fd0d9c5ccef457

commit 19f16a5138c95e212161ecfeb1fd0d9c5ccef457
Author: Esmael El-Moslimany <aee@chromium.org>
Date: Wed May 09 20:23:50 2018

MD Extensions: avoid sending remove event when adding immediately afterward

Bug:  836988 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Iedcac22a68cb73f68f314f35b1e1c771ab52c8ad
Reviewed-on: https://chromium-review.googlesource.com/1036199
Commit-Queue: Esmael El-Moslimany <aee@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557298}
[modify] https://crrev.com/19f16a5138c95e212161ecfeb1fd0d9c5ccef457/chrome/browser/extensions/api/developer_private/developer_private_api.cc
[modify] https://crrev.com/19f16a5138c95e212161ecfeb1fd0d9c5ccef457/chrome/browser/resources/md_extensions/manager.js
[modify] https://crrev.com/19f16a5138c95e212161ecfeb1fd0d9c5ccef457/chrome/browser/resources/md_extensions/service.js
[modify] https://crrev.com/19f16a5138c95e212161ecfeb1fd0d9c5ccef457/chrome/common/extensions/api/developer_private.idl
[modify] https://crrev.com/19f16a5138c95e212161ecfeb1fd0d9c5ccef457/chrome/test/data/webui/extensions/test_service.js
[modify] https://crrev.com/19f16a5138c95e212161ecfeb1fd0d9c5ccef457/third_party/closure_compiler/externs/developer_private.js