1271767 - Add probes to determine what value to set full-screen-api.transition.timeout to

Status: RESOLVED DUPLICATE of bug 1271160

(Core :: DOM: Content Processes, defect, P1)

Description

[Mike Conley (:mconley) (:⚙️)]

We currently have this value set at full-screen-api.transition.timeout which is how long we will wait during a DOM fullscreen transition for content to complete re-laying itself out for fullscreen before "bringing up the lights" for the fullscreen transition. If the time to wait for content to say "ready" exceeds full-screen-api.transition.timeout, then we "bring up the lights" early.

500ms was, I believe, picked rather arbitrarily, and this can easily lead to situations where the user sees the fullscreen transition "finish", but then the content re-lays itself out not long after (see bug 1266799 or bug 1243014 for examples).

What we should do is probably get some telemetry data to determine what value to set full-screen-api.transition.timeout to. That'd mean finding out how long it usually takes for content to re-lay itself out for a DOM fullscreen transition.

With that information, we could potentially tune full-screen-api.transition.timeout to an agreeable value that would account for the majority of cases.

Comment 1

[Jim Mathies [:jimm]]

Xidorn, is this something you might have the time for? We want to see how well we do here and use that information to optimize the timeout for our user base.

Comment 2

[Xidorn Quan [:xidorn] UTC+10]

Sounds like what I'm doing in bug 1271160.