Visual progress calculation from paint events

[pmdartus]

The current visual progress calculation is based on the video capture method.
The Speed Index also provides another approach to calculate the visual progress using the paint events.

[paulirish]

TBH I think it's unnecessary to use the paint event approach. It's a fallback case because the browser can't look at pixel data. But the metric is intended to be perceptual, so any approach that analyzes color values will be superior to those that dont.

[paulirish]

i spoke with the chrome engineer who implemented the paint event algorithm and he indicated it's less accurate. Given that, I think you should close this issue. :)

[pmdartus]

Thanks for the update!