When a tab is restored, because Chrome has restarted, or Chrome has foregrounded a tab whose memory was evicted (either due to app or tab backgrounding), the last page on that tab is reloaded. The reload should attempt to use cache, but some data might be retrieved from the network.

We should measure how much data is used from the network and from cache on such tab restores. 

Ideally, also, the data use should be tracked separately for the initial page load vs e.g., periodic XHR afterwards.