You can now activate this new and important button in Google Chrome
Chrome engineers are working on adding a new button that allows us to play or pause multimedia content and place it in the browser toolbar. In fact, this will make it easier to temporarily pause or resume the multimedia content currently running in your browser, independent of the tab from which it comes.
This new feature has been named Global Media Controls or GMC and has just been enabled in the Chrome Canary version. Specifically, the new control button appears to the right of the title bar, and when clicked it will display a pop-up window that lets users pause or resume playback Currently running multimedia content.
This functionality can be activated as long as you have the latest version of Chrome Canary. For this purpose, the first thing you will do is download this version from the following link:
In order to use the GCM multimedia control button, we will only have to write the following link in the Canary Chrome title b
chrome://flags/#global-media-controls
the option as in the image then, restart the browser

This way, this new button will appear for you to turn off or resume playback of multimedia content.