With HTTP/2 image loads can saturate the connection and cause the loading of more important resources to be delayed (https://blog.cloudflare.com/better-http-2-prioritization-for-a-faster-web/ for a pretty good analysis). We should do some scheduling in the network process.
Created attachment 418281 [details]
Created attachment 418415 [details]
Created attachment 418429 [details]
Comment on attachment 418429 [details]
I didn't check the EWS issues; might be something to fix before landing.
Created attachment 418522 [details]
Committed r271946: <https://trac.webkit.org/changeset/271946>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 418522 [details].