This works for toolkit-views in Windows, so it's possible we just haven't implemented that bit of Drag & Drop yet (see also  Issue 543732 ).

Bulk-labelling blocking bugs for  Issue 603372 

bulk-tagging Phase1 for M52

Some thoughts, having recently done a bunch of refactoring in this area:

The "new" way of doing things is to put all the relevant information in an NSDraggingItem, and then pass that around. This is actually a nice simplification.

See ui/base/clipboard/clipboard_util_mac.mm for a bunch of utility methods I recently added, and some subtleties about UTIs.

Please avoid deprecated methods of interacting with the clipboard, including super old Mozilla code:
https://bugs.chromium.org/p/chromium/issues/detail?id=599264

Also, note that the new dragging API (beginDraggingSessionWithItems:event:source:) is asynchronous, whereas the deprecated one (dragImage:...) was synchronous.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6bdd9b835d5f6ef1ef209e301d02af2f0b12485e

commit 6bdd9b835d5f6ef1ef209e301d02af2f0b12485e
Author: spqchan <spqchan@chromium.org>
Date: Thu May 05 20:26:47 2016

Modify Pasteboard handling in OSExchangeData

BUG= 599585 

Review-Url: https://codereview.chromium.org/1947153003
Cr-Commit-Position: refs/heads/master@{#391894}

[modify] https://crrev.com/6bdd9b835d5f6ef1ef209e301d02af2f0b12485e/ui/base/dragdrop/os_exchange_data_provider_mac.mm

https://codereview.chromium.org/1964283002/

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cf5eeb5c035be5a986fa1a6488f2189e7aebe198

commit cf5eeb5c035be5a986fa1a6488f2189e7aebe198
Author: spqchan <spqchan@chromium.org>
Date: Fri Jun 03 21:17:19 2016

MacViews: Implemented Drag & Drop

Created a Drag & Drop client on Mac that bridges between the Views
and native OSX's drag and drop. This approach is based on the Aura
approach.

BUG= 599585 
TEST= Run the view unit test: DragDropClientMacTest

Review-Url: https://codereview.chromium.org/1964283002
Cr-Commit-Position: refs/heads/master@{#397801}

[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/base/mac/sdk_forward_declarations.h
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/base/BUILD.gn
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/base/dragdrop/drag_drop_types.h
[add] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/base/dragdrop/drag_drop_types_mac.mm
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/base/dragdrop/drag_utils.cc
[delete] https://crrev.com/d5c75af8c710870b5a5f4067f17d72b50a21cd2f/ui/base/dragdrop/drag_utils_aura.cc
[delete] https://crrev.com/d5c75af8c710870b5a5f4067f17d72b50a21cd2f/ui/base/dragdrop/drag_utils_mac.mm
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/base/dragdrop/os_exchange_data.h
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/base/dragdrop/os_exchange_data_provider_mac.h
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/base/dragdrop/os_exchange_data_provider_mac.mm
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/base/ui_base.gyp
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/views/cocoa/bridged_content_view.h
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/views/cocoa/bridged_content_view.mm
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/views/cocoa/bridged_native_widget.h
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/views/cocoa/bridged_native_widget.mm
[add] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/views/cocoa/drag_drop_client_mac.h
[add] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/views/cocoa/drag_drop_client_mac.mm
[add] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/views/cocoa/drag_drop_client_mac_unittest.mm
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/views/views.gyp
[modify] https://crrev.com/cf5eeb5c035be5a986fa1a6488f2189e7aebe198/ui/views/widget/native_widget_mac.mm

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/851eb42016eeca7ac932921164bb1fdb3a5844b3

commit 851eb42016eeca7ac932921164bb1fdb3a5844b3
Author: tapted <tapted@chromium.org>
Date: Mon Jun 06 00:49:47 2016

Add missing curlies in CocoaDragDropDataProvider

Otherwise the |data_| member is actually static (and causes a static
initializer).

BUG= 599585 
TBR=spqchan@chromium.org

Review-Url: https://codereview.chromium.org/2039723002
Cr-Commit-Position: refs/heads/master@{#397956}

[modify] https://crrev.com/851eb42016eeca7ac932921164bb1fdb3a5844b3/ui/views/cocoa/drag_drop_client_mac.mm

@spqchan: I can't get this to work correctly on the latest Canary. It works sometimes, but not consistently. Can you check once? Maybe this regressed? 

I can get it work on Canary. What are your reproduction steps?

+ karandeepb for Comment 14

Repro steps-
(0) Turn on chrome://flags/#mac-views-dialogs
(1) Go to a HTTP auth dialog.
(2) Select text in another application (Sublime Text in this case).
(3) Drag the selected text into the username field

Also, attaching a screencast for Canary. 

Deleted: dragdrop2.mov 23.2 MB

dragdrop2.mov 23.2 MB Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/05fd4c1a2fcbd2cb6ef5b5eceffa8e2f09579a35

commit 05fd4c1a2fcbd2cb6ef5b5eceffa8e2f09579a35
Author: spqchan <spqchan@chromium.org>
Date: Sat Sep 03 00:50:48 2016

[MacViews] Fix Drag and Drop bugs

Made changes so that MacViews can accept drops from
other applications.

BUG= 599585 

Review-Url: https://codereview.chromium.org/2307633002
Cr-Commit-Position: refs/heads/master@{#416419}

[modify] https://crrev.com/05fd4c1a2fcbd2cb6ef5b5eceffa8e2f09579a35/ui/base/dragdrop/drag_drop_types.h
[modify] https://crrev.com/05fd4c1a2fcbd2cb6ef5b5eceffa8e2f09579a35/ui/base/dragdrop/drag_drop_types_mac.mm
[modify] https://crrev.com/05fd4c1a2fcbd2cb6ef5b5eceffa8e2f09579a35/ui/views/cocoa/drag_drop_client_mac.mm
[modify] https://crrev.com/05fd4c1a2fcbd2cb6ef5b5eceffa8e2f09579a35/ui/views/cocoa/drag_drop_client_mac_unittest.mm

Fixed the issue. Thanks for catching it!