Performance testing for mobile-html.
None of the calls subtract out network load time so pages that haven't been loaded before will be slower as they're uncached.
setTimeout with 1ms inside of a window.requestAnimationFrame seems to be the best way to accurately wait for the page to render before receiving the callback.
Loads the page into the mobile-html-shell page and measures the time between calling pagelib.c1.Page.load( and the page rendering.
Loads the first section of the page into the mobile-html-shell page and measures the time between calling pagelib.c1.Page.loadProgressively( and the page rendering the first section. This is still loading the full content but only appending the first section immediately. The rest of the content is added after a 100ms delay. For longer articles, the time to first paint is noticeably faster on device with this approach when compared to appending the whole article at once.
Loads the full mobile-html page using en.wikipedia.org/api/rest_v1/page/mobile-html https://gerrit.wikimedia.org/r/c/mediawiki/services/mobileapps/+/534531. Measures the time between sending the network request and the {action: 'setup'} callback from pagelib.