* enable plznavigate code path
* AtomBrowserClient::GetGeolocationApiKey returns the right default
* use IsLoadingToDifferentDocument to identify top level navigation in mainFrame
* use candidate site instance when available
* spec: don't test httpReferrer option for file origin
* update libcc ref
* affinity: only group same site in this mode
* plznavigate: don't emit did-get-response-details event for blob scheme