1) we have already  WebContentsObserver -- it is ApplicationEventRouter. So maybe ApplicationEventRouter could send some kind of event, like "Application started" or "Main Document Loaded" or smth like that ( @kenchris, maybe you can suggest a better name)?
2) ApplicationProcessManager would need a method "CloseRunningApplication()" and for the given purpose we should think how it can obviate launching of "onsuspend" handlers.
3) So, in HandleApplicationManagementCommands (maybe there is a better place?) we create observer for "Main Document Loaded" event that closes the app inside its Observe() function, and then launch the app.

wdyt?