Comment 9 for bug 1494197

The content-hub-service needs to be able to start prompt sessions for multiple requests. Use cases:

1. Paste Other from the UITK's TextField invokes the clipboard UI as a trust prompt started by content-hub-service
2. Out of process peer picker, we have a new peer picker that doesn't run in the process of the requesting app. It's started in a prompt session by content-hub-service
3. Content picking. The content-hub-service starts apps that provide a content picker in a trust prompt.
4. Printing dialog is started by the content-hub-service.

All of these use cases require starting the prompt from the content-hub-service process. We would like to do this without stopping other prompts that might already be in use.