On bug 175569 support for Server Timing API <https://w3c.github.io/server-timing/> was added to WebKit. Support for it under WebKit is still classified as experimental and the implementation is not complete (e.g. PerformanceNavigationTiming is not implemented) The feature is guarded with a run-time flag (ServerTimingEnabled) which is disabled by default But I think it should be enabled for GTK and WPE when experimental features are enabled A layout test for this is imported/w3c/web-platform-tests/server-timing/server_timing_header-parsing.html The layout test passes currently because the feature is getting enabled on WTR
Created attachment 381679 [details] Patch
Comment on attachment 381679 [details] Patch Clearing flags on attachment: 381679 Committed r251535: <https://trac.webkit.org/changeset/251535>
All reviewed patches have been landed. Closing bug.