Google has enabled it to use picture-in-picture mode in its latest version of the Chrome browser. This makes it possible for example to keep a YouTube video in the foreground while other programs are being opened.
The updates are in version 70 of the Chrome browser, and Google employee François Beaufort left in a message on Google+ know that the picture-in-picture is now turned on by default. Incidentally, developers have to build support for this on their website. There is also an extension for Chrome that allows users to turn on the picture-in-picture on any webpage for videos.
On YouTube, picture-in-picture mode is already built-in; Users can open a menu by right-clicking twice, selecting picture-in-picture. Then the played video can be kept in the foreground. This is also possible if another application is opened.
According to Beaufort, picture-in-picture is supported on Windows, Linux and the Mac. The intention is that support is built in on the Chrome browsers for Android and Chrome OS. Incidentally, it is possible to use the mode there; therefore chrome:// flags / # enable-surfaces-for-videos should be turned on, as it is still an experimental version.