You can get this result using Chorme at the same time the following plugin:
Mymail-Crypt for Gmail™
https://chrome.google.com/webstore/detail/mymail-crypt-for-gmail/jcaobjhdnlpmopmjhijplpjhlplfkhba?utm_source=plus
Here are details
Extension implementing GPG into Webmail (Gmail™) using the OpenPGP.js library. This project is no way affiliated with Google™.
Mymail-Crypt for Gmail™ aims to make OpenPGP encryption available and used
by anyone.
This project is in no way affiliated with Google™.
***If you are having trouble with this extension, particularly in regards
to key imports/working with other clients, please reach out to me.
To get started
*Install this Extension
*Tools -> Extensions -> under Mymail-Crypt click the options page
*Read over the help, import or generate a key as is necessary
*Give your public key to your friends, import theirs into the options page
*In Gmail™ simply click encrypt to encrypt a mail you're writing
*In Gmail™ simply click the decrypt to read a mail from a friend.
Mymail-Crypt acts as a layer on top of your Gmail™ experience that allows
you to seamlessly encrypt