Comment 6 for bug 1389761

> (b) automatically reflect, and adjust, the system volume for the active output role, without the app having to do anything at all;

i dont think that works, the item should have a way to select for which role you want the volume change since we auto-change roles all the time. what if a notification goes off while the app is open ? you will suddenly adjust the notification volume. what if your app uses a certain role that only gets activated if you actually play a sound.
my alternate webapp container framework allows to enable haptic feedback and click sounds for links in websites, if i enable that i can see the volume indicator jump to full volume for the lenght of the sound. if i would want to provide the mentioned slider to adjust the sound effect volume it would always only point to the main system volume unless the effect is played.
the toolkit widget should have a field to define the type of role you want it to change.