ENVIRONMENT and STATS
For syncing clients:
From chrome://version, please provide the OS and Chrome build number.
From about:sync, copy/paste the tab contents here, or select the Data tab
and click [Dump sync events to text].

REPRO STEPS
Login to gmail account and click on "Drafts".
Click on a draft email(compose box opens).
Click on discard draft button at the bottom right of the compose box.
"Your message is discarded appears"

But....Draft mail is still not deleted.Its still available in the list.

Again click on the draft mail and repeat the above steps.

--The email is deleted twice,"Your message is discarded appears"

ACTUAL RESULTS
Login to gmail account and click on "Drafts".
Click on a draft email(compose box opens).
Click on discard draft button at the bottom right of the compose box.
"Your message is discarded appears"

But....Draft mail is still not deleted.Its still available in the list.

Again click on the draft mail and repeat the above steps.

--The email is deleted twice,"Your message is discarded appears"

EXPECTED RESULTS
On clicking on the "Discard draft" button the email should get deleted as well as it should be removed from the list.

Performance issue---Its takes a while to delete the draft mail and also sync problem with the mail list.

ADDITIONAL INFO
Anything else which may help us debug the issue; screenshots of error
messages or states are always helpful.