Google seems to be allowing you to change file permissions on Google Drive directly from Gmail.
Let us remember how it was before.
Send a link to a friend to download one archive that is stored in your Google Drive, but you forgot to give it permission to download it.
Well, you can now access Google Drive files directly from your Gmail. See the following gif published by the company:
Google announced the update and confirmed that you can now grant viewing, commenting, or editing rights to Google Drive files directly through Gmail. In addition the company stated that you can change the permissions of Google Drive files to Appliances with iOS, Android and also on the web for Gmail.
The company has already started rolling out the update to users of its services. If you're waiting for the new addition, it should be activated in your account by November 7th.
This Gmail update makes the service much easier for users and is obviously an example of smart UX.