RESOLVED FIXED315664
[Site Isolation] iframe monitor tests are failing 
https://bugs.webkit.org/show_bug.cgi?id=315664
Summary [Site Isolation] iframe monitor tests are failing
Anthony Tarbinian
Reported 2026-05-27 08:24:44 PDT
The following tests are failing with site isolation: http/tests/iframe-monitor/eligibility.html http/tests/iframe-monitor/iframe-unload.html http/tests/iframe-monitor/throttler.html http/tests/iframe-monitor/workers/service-worker-not-count-twice.html http/tests/iframe-monitor/workers/service-worker.html http/tests/iframe-monitor/workers/shared-worker.html Note that this doesn't cover http/tests/iframe-memory-monitor/media-video-autoplay-in-frames.html These 6 tests in http/tests/iframe-monitor/ timed out under --site-isolation. The tests use a WebKit feature which enforces a resource usage threshold for iframes. When an iframe goes over the resource usage threshold, the iframe is killed by getting swapped out with a gray placeholder iframe that reads: "this frame is hidden". The first bug was that WebLocalFrameLoaderClient::didExceedNetworkUsageThreshold assumes that the main frame is a local frame. This isn't true with site isolation. It uses the local main frame to grab the URL of the main frame and send it via the Messages::NetworkConnectionToWebProcess::ShouldOffloadIFrameForHost IPC message. With site isolation enabled, the main frame's document wasn't available and didExceedNetworkUsageThreshold returned early, never sending the NetworkConnectionToWebProcess::ShouldOffloadIFrameForHost IPC message. The second bug was that LocalFrame::showResourceMonitoringError tried to use ownerElement() to set the srcdoc of the iframe. With site isolation enabled, the owner element was in a different process and was nullptr. The third bug, involves settings on internals.* to not be propagated to all processes which is problematic for site isolation.
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Radar WebKit Bug Importer
Comment 1 2026-05-27 08:24:50 PDT
<rdar://problem/178052024>
Anthony Tarbinian
Comment 2 2026-05-27 12:57:31 PDT
Pull request: https://github.com/WebKit/WebKit/pull/65806
EWS
Comment 3 2026-05-28 10:24:52 PDT
Committed 314057@main (270a9fa5f162): <https://commits.webkit.org/314057@main> Reviewed commits have been landed. Closing PR #65806 and removing active labels.
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