This feature is experimental. It may be changed or removed in a future version.
This event is emitted after a layer's location property has changed value.
This event is also emitted when a layer without visible history
has reached a new location. If you are only interested in changes the are visible in
the browser's address bar, observe
The event is also event for location changes on the root layer.
This event is not emitted when an overlay is opened. For this observe
The new location URL.