Right now, when you issue a content suggestions fetch from chrome://snippets-internals, you can get the raw JSON response, but there's no way to see the request that was sent (headers and JSON payload). These would be very useful for debugging. We should add a hook to show it.

We might want to be able to see the most recent request (background or NTP), but at the least, a request issued manually from the internals page should show up.