With Google I/O just a few days away, the Chrome team has added push alert support for apps in its browser or Chrome OS. Google Cloud Messaging for Chrome is designed to let apps receive notifications from outside Chrome and respond to them more efficiently. Before introducing Cloud Messaging for Chrome, apps that wanted to respond to an outside trigger — like a news alert or a message that the user has sent — would have to keep checking back with a server, using more data and power. Now, developers can have the app request a token, then have their server post a message with said token to Cloud Messaging. From there, as long as the user is signed into Chrome, it will alert the app and deliver the message.
Essentially, this is a way to let Chrome apps only run when they're needed. So soon before Google's big event, though, it's also tempting to connect this kind of upgrade to a future launch of Google Now for Chrome, which has been strongly hinted at in Chromium and Chrome OS updates. Either way, developers can check out the Cloud Messaging page now, and a Google blog post explains a little more about what's behind the process.