Crostini, the Linux side of Chrome OS is getting support for drag and drop from Chrome. The code commit that I spotted today talks about adding support for this feature. This, however, will work only from Chrome to Crostini and not the other way around, yet.

The bug that tracks this feature covers drag and drop for Crostini apps in general. Today’s code commit, however, from the look of it, is only a small part of the whole request.

Support for drag+drop from chrome to crostini

There were several modifications necessary:
 - We need to offer utf8 or some applications (at least gedit) won't
   accept utf16.
 - We refactored the current architecture to re-use more code.
 - There was an error where "finish" and "destroy" were flipped, which
   causes the client application to crash.

Does not support:
 - crostini to chrome
 - X11 clients
 - most mime types (only utf8/16 supported)

The drag and drop feature is currently marked as a feature for Chrome OS version 78 which will take a few months to reach the Stable channel. However, if you are a Crostini enthusiast, this should be a piece of exciting news already. You could get to test this feature in the Canary or Dev channel before it becomes available in the Stable channel.