Connections can be shared between browser tabs, so two tabs may use the same connection to a single origin. This obviously has implications for privacy e.g. if

Connections can be shared between browser tabs, so two tabs may use the same connection to a single origin. This obviously has implications for privacy e.g. if that connection is to a third-party so Firefox and Chrome are starting to partition network connections. If you capture a Netlog in Chrome, you'll a NetworkIsolationKey (?) entry, and consisting of top-level frame origin, frame origin, request origin (or similar) that's used to key the connection an limit it's use