ProgressTracker currently decides that main load is complete when the main frame stops loading. However it is common that timers and onload events trigger more loads immediately (for example by inserting iframes) and loading continues visually. These should be considered as part of the main load for paint throttling and speculative tiling coverage purposes.
Created attachment 222015 [details]
Comment on attachment 222015 [details]
r=me, but please switch this over to using monotonically increasing time instead of WTF::currentTime().