Surface chunk network timing details

[jtedesco]

For sites using HTTP chunking for the main page, it can be useful to disambiguate between the time an element is displayed (e.g. from the element timing API) and when it arrives on the client at the network level but is not yet processed.

For instance, if the navigation timing API surfaced the time and size of each HTTP chunk received on the client, it would be possible to map this data back to the time specific elements were received from the network, and to use this to determine the delay between receiving and displaying a particular element.

[nhelfman]

For instance, if the navigation timing API surfaced the time and size of each HTTP chunk received on the client

This would be a great and very useful addition to navigation timing!