1382999 - use HTTP OMT data delivery while loading worker resource

Status: NEW

(Core :: DOM: Workers, enhancement, P3)

Description

[Shih-Chiang Chien [:schien] (UTC+8) (use ni? plz)]

From telemetry [1] I found worker-related HTTP requests are not utilizing off-main-thread data delivery. Worker script loader uses nsStreamLoader/nsStreamListenerTee and LoaderListener to load the resource. However, |RetargetDeliveryTo| is not called in ScriptLoaderRunnable::OnStartRequest. Therefore, HTTP OMT is not activated.

[1] https://mzl.la/2ugPhaU
[2] https://searchfox.org/mozilla-central/rev/3a3af33f513071ea829debdfbc628caebcdf6996/dom/workers/ScriptLoader.cpp#969
[3] https://searchfox.org/mozilla-central/rev/3a3af33f513071ea829debdfbc628caebcdf6996/dom/workers/ScriptLoader.cpp#674

Comment 1

[Ben Kelly [:bkelly, not reviewing]]

We should do this, but note that it won't help with service workers.