315664 2026-05-27 08:24:44 -0700 [Site Isolation] iframe monitor tests are failing 2026-05-28 10:24:54 -0700 1 1 1 Unclassified WebKit WebKit Process Model WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED InRadar P1 Normal --- 1 a.tarbinian webkit-unassigned nham webkit-bug-importer oldest_to_newest 2214973 0 a.tarbinian 2026-05-27 08:24:44 -0700 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. 2214974 1 webkit-bug-importer 2026-05-27 08:24:50 -0700 <rdar://problem/178052024> 2215060 2 a.tarbinian 2026-05-27 12:57:31 -0700 Pull request: https://github.com/WebKit/WebKit/pull/65806 2215359 3 ews-feeder 2026-05-28 10:24:52 -0700 Committed 314057@main (270a9fa5f162): <https://commits.webkit.org/314057@main> Reviewed commits have been landed. Closing PR #65806 and removing active labels.