A recent commit to the Chromium Gerrit named Adds support for badging scopes shows that Google is working on a Badging API. Websites will use Google’s prospective API to display unread notification badges on bookmarks, open tabs and web apps and PWAs. These badges will work similarly to the one you can see in iOS and Windows.
Google’s developers have explained the idea of the Badging API in a proposal published on GitHub. It seems like Google was planning to implement the idea for a while. Those who are using the desktop version of Google Chrome must have noticed the notification dots. Now the next step would definitely be adding an unread count on top of the notification dot.
The mock images of the badge from the GitHub project page indicate that the unread badges are based on the idea of Android icons that serve notifications on your phone. If Google decides to go ahead with its plan, it is definitely going to be a useful functionality.
It would be helpful for Chrome users who usually have different messaging apps such as Google Messages, WhatsApp, and Slack opened in separate tabs. Moreover, the Bookmark unread badges will be designed to eliminate the need for manually open the web page. The badge will directly inform you about unread notifications. The idea sounds pretty interesting because it will eventually save the memory resources required to open the page.
According to the design document, developers can choose between the unread count or the indicator to display the notification.
If you just want to show a status indicator flag without a number, use the Boolean mode of the API by calling Badge.set without an argument, and Badge.clear (which might be done to indicate that it is the player’s turn to move in a multiplayer game).
It is worth mentioning that the Badging API is currently in its early proposal stages. However, there is a good chance that the Chromium team will start working on the project very soon. Meanwhile, you can go through the Badging API and Badging API Explainer to explore the details.