I want to take this issue. 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d2e643efc4cceed77e046658a588f1559f1b1e88

commit d2e643efc4cceed77e046658a588f1559f1b1e88
Author: shahriar.rostami <shahriar.rostami@gmail.com>
Date: Wed Nov 23 05:41:30 2016

Fixed dragging a folder from bookmark manager to open all elements in new tabs

Dropping a bookmark folder on Omnibox or Tab strip will open all of the urls in
separate tabs.

Note that this does not include urls within nested folders, because
BookmarkNodeData.WriteToClipboard (bookmark_node_data.cc:190) does not put urls
from nested folders into clipboard.

I have two questions from reviewers:

1) Do we have to record metrics in ToolbarController like what we have in
TabStripController.OpenUrl()?

2) I could not find any unit test for testing DropUrls of tab_strip_controller.mm
and toolbar_controller.mm, am I right?

BUG= 661765 

Review-Url: https://codereview.chromium.org/2502483002
Cr-Commit-Position: refs/heads/master@{#434124}

[modify] https://crrev.com/d2e643efc4cceed77e046658a588f1559f1b1e88/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
[modify] https://crrev.com/d2e643efc4cceed77e046658a588f1559f1b1e88/chrome/browser/ui/cocoa/toolbar/toolbar_controller.mm

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8caa17af5b4d349cb2a0df07b2b79824d89591db

commit 8caa17af5b4d349cb2a0df07b2b79824d89591db
Author: erikchen <erikchen@chromium.org>
Date: Thu Dec 15 16:59:06 2016

Revert of Fixed dragging a folder from bookmark manager to open all elements in new tabs (patchset #7 id:120001 of https://codereview.chromium.org/2502483002/ )

Reason for revert:
Reverting because this introduces a bug:
https://bugs.chromium.org/p/chromium/issues/detail?id=672805

Original issue's description:
> Fixed dragging a folder from bookmark manager to open all elements in new tabs
>
> Dropping a bookmark folder on Omnibox or Tab strip will open all of the urls in
> separate tabs.
>
> Note that this does not include urls within nested folders, because
> BookmarkNodeData.WriteToClipboard (bookmark_node_data.cc:190) does not put urls
> from nested folders into clipboard.
>
> I have two questions from reviewers:
>
> 1) Do we have to record metrics in ToolbarController like what we have in
> TabStripController.OpenUrl()?
>
> 2) I could not find any unit test for testing DropUrls of tab_strip_controller.mm
> and toolbar_controller.mm, am I right?
>
> BUG= 661765 
>
> Committed: https://crrev.com/d2e643efc4cceed77e046658a588f1559f1b1e88
> Cr-Commit-Position: refs/heads/master@{#434124}

TBR=avi@chromium.org,shrike@chromium.org,shahriar.rostami@gmail.com
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG= 661765 

Review-Url: https://codereview.chromium.org/2572363002
Cr-Commit-Position: refs/heads/master@{#438851}

[modify] https://crrev.com/8caa17af5b4d349cb2a0df07b2b79824d89591db/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
[modify] https://crrev.com/8caa17af5b4d349cb2a0df07b2b79824d89591db/chrome/browser/ui/cocoa/toolbar/toolbar_controller.mm

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/82ba88e6bff66deb3b4a9c06e966637538cd9f89

commit 82ba88e6bff66deb3b4a9c06e966637538cd9f89
Author: shahriar.rostami <shahriar.rostami@gmail.com>
Date: Tue Dec 20 05:09:43 2016

Fixed dragging a folder from bookmark manager to open all elements in new tabs

Dropping a bookmark folder on Toolbar or Tab strip will open all of the urls in
separate tabs.

The first URL of dragged/dropped bookmark on toolbar_controller should be opened
in the current opening tab.

BUG= 661765 

Review-Url: https://codereview.chromium.org/2587763002
Cr-Commit-Position: refs/heads/master@{#439713}

[modify] https://crrev.com/82ba88e6bff66deb3b4a9c06e966637538cd9f89/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
[modify] https://crrev.com/82ba88e6bff66deb3b4a9c06e966637538cd9f89/chrome/browser/ui/cocoa/toolbar/toolbar_controller.mm

Appears like that changelist fixed the issue.  Yay! :-)