1st let me say I love the idea of a MPRIS browser extension.
I've tested your extension against my GNOME Shell extension and it seems to work rather well with the exception that you can't raise the player (the browser in this case) because you set CanRasie to false and don't have a Raise method.
It would be awesome if raising would raise the browser and switch to the appropriate tab.
It would be also nice if your extension downloaded the fav icon of the "players" to ~/.local/share/icons so MPRIS widgets could find them. Basically if you set the DesktopEntry prop to the name of the fav icon my extension should be able to find the icon in ~/.local/share/icons
1st let me say I love the idea of a MPRIS browser extension.
I've tested your extension against my GNOME Shell extension and it seems to work rather well with the exception that you can't raise the player (the browser in this case) because you set CanRasie to false and don't have a Raise method.
It would be awesome if raising would raise the browser and switch to the appropriate tab.
It would be also nice if your extension downloaded the fav icon of the "players" to
~/.local/share/iconsso MPRIS widgets could find them. Basically if you set the DesktopEntry prop to the name of the fav icon my extension should be able to find the icon in~/.local/share/icons