browser.runtime.onRestartRequired.addListener(listener)
browser.runtime.onRestartRequired.removeListener(listener)
browser.runtime.onRestartRequired.hasListener(listener)

Events have three functions:

addListener(callback)

Adds a listener to this event.

removeListener(listener)

Stop listening to this event. The listener argument is the listener to remove.

hasListener(listener)

Checks whether a listener is registered for this event. Returns true if it is listening, false otherwise.

function

A callback function that will be called when this event occurs. The function will be passed the following arguments:

reason

A runtime.OnRestartRequiredReason value — the reason that the event is being dispatched.