Better visualization of Lantern simulation (filmstrip & net requests)

[Munter]

Feature request summary

In the new lantern simulation it seems simulated timings aren't applied to numbers inside different audits, like network-requests or screenshot-thumbnails, making visualizations of these audits incompatible with the reported perceived performance metrics

What is the motivation or use case for changing this?

Visualizations are helpful in drilling down into reasons for performance issues. Having a report of slow perceived performance metrics without being able to correlate them with a network waterfall or screenshots of rendering over time makes it hard to debug issues

How is this beneficial to Ligthhouse?

The lighthouse output could be used to drive more detailed reports than the one that is currently produced by the html reporter

[patrickhulce]

I like this @Munter thanks for filing! We've been working on pieces of this. There's somewhat of a debug option currently if you're running with the CLI, use the --save-assets flag to dump traces and set the env variable LANTERN_DEBUG=true then you'll get traces with the lantern timings for each metric (at which point you can view the waterfall by opening it in DevTools performance panel).

Agreed this hardly a first class visualization, but it's progress so stay tuned :)

[martinschierle]

+1 for getting this fixed, I also rely on the resource and screenshot timings for my project (see g.co/perfgame)