Bug 255200

Summary:	Implement VisibilityStateEntry
Product:	WebKit	Reporter:	Noam Rosenthal <noam>
Component:	Page Loading	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	achristensen, beidson, cdumez, miguel_salinas, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified

Description Noam Rosenthal 2023-04-08 23:43:11 PDT

VisibilityStateEntry is a new performance timeline entry type that tracks page visibility changes. It helps correlate other performance timeline entries with environment state.
New spec change: https://github.com/whatwg/html/pull/8206

See tests: https://wpt.fyi/results/page-visibility/visibility-state-entry.tentative.html?label=experimental&label=master&aligned

Actual results:

The above tests fail

Expected results:

The above tests should succeed

Corresponding Mozilla bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1827127
Corresponding Chromium bug: https://bugs.chromium.org/p/chromium/issues/detail?id=1103451
Spec PR: https://github.com/whatwg/html/pull/8206

Comment 1 Radar WebKit Bug Importer 2023-04-15 23:44:16 PDT

<rdar://problem/108101344>