A new commit found in the Chromium Gerrit suggests that Quick Reply support could be coming to Chrome for Android by the time we get to Chrome 70 or 71 later this year. The feature would allow for users to reply to notifications directly from within Chrome that sites pop up to users on a site.
Quick Replies themselves are not new and are supported through Android and apps that developers have enabled to support. This would bring the same functionality to Chrome and would have the same benefit of being able to reply to a notification without having to leave the browser.
Today, and for some time now, sites have been able to send notification to users when visiting a site. But those interactions are pretty much one way and are truly a notification. This change, if it does get enabled, would allow for interactions to happen. Think of a more streamline chat bot or technical support as a use case.
As I often warn, reading Chromium commits is a bit of a tea leaf reading exercise and just because its in the code, it doesn’t mean it will actually be enabled. There are a lot of user implications if it is and all indications point to Google still doing a lot of testing on this prior to release. Indeed, as of now, the feature isn’t in the Canary build of Chrome for Android which is based on Chrome 70.