Bug 313569 – [Site Isolation] COOP error reporting doesn't work

• Component: New Bugs
• Status: RESOLVED FIXED

[Anthony Tarbinian]

Several tests in 
imported/w3c/web-platform-tests/html/cross-origin-opener-policy/reporting/navigation-reporting
are broken with site isolation enabled.

These tests check that the browser is able to report a Cross-Origin-Reporing-Policy (COOP) violation. 
This is a feature which sends an HTTP POST request to a certain "reporting endpoint" when a COOP
violation is detected https://w3c.github.io/reporting 

​imported/w3c/web-platform-tests/html/cross-origin-opener-policy/reporting/navigation-reporting/report-only-four-reports.https.html
imported/w3c/web-platform-tests/html/cross-origin-opener-policy/reporting/navigation-reporting/report-only-from-unsafe-none.https.html
imported/w3c/web-platform-tests/html/cross-origin-opener-policy/reporting/navigation-reporting/report-only-same-origin-report-to.https.html
imported/w3c/web-platform-tests/html/cross-origin-opener-policy/reporting/navigation-reporting/reporting-popup-same-origin-allow-popups-report-to.https.html
imported/w3c/web-platform-tests/html/cross-origin-opener-policy/reporting/navigation-reporting/reporting-popup-same-origin-coep-report-to.https.html
imported/w3c/web-platform-tests/html/cross-origin-opener-policy/reporting/navigation-reporting/reporting-popup-same-origin-report-to.https.html
imported/w3c/web-platform-tests/html/cross-origin-opener-policy/reporting/navigation-reporting/reporting-popup-same-origin.https.html
imported/w3c/web-platform-tests/html/cross-origin-opener-policy/reporting/navigation-reporting/reporting-popup-unsafe-none-report-to.https.html

Here is the text diff from one of the tests:

-PASS coop reporting test A test with both COOP and COOP report only setup to CROSS_ORIGIN with same-origin-allow-popups; report-to="coop-popup-report-endpoint", require-corp, same-origin; report-to="coop-popup-report-only-endpoint", require-corp
+FAIL coop reporting test A test with both COOP and COOP report only setup to CROSS_ORIGIN with same-origin-allow-popups; report-to="coop-popup-report-endpoint", require-corp, same-origin; report-to="coop-popup-report-only-endpoint", require-corp promise_test: Unhandled rejection with value: "No report matched the expected report for endpoint: coop-report-endpoint, expected report: {\"body\":{\"disposition\":\"enforce\",\"effectivePolicy\":\"same-origin-allow-popups\",\"nextResponseURL\":\"/uuid=(uuid)$/\",\"type\":\"navigation-from-response\"},\"url\":\"https://web-platform.test:9443/html/cross-origin-opener-policy/reporting/navigation-reporting/report-only-four-reports.https.html\",\"type\":\"coop\"}, within available reports: []"
 PASS verify remaining reports

This happens because the current WebKit code in WebPage::sendReportToEndpoints uses a LocalFrame to kick off
the HTTP POST sequence. With site isolation, the frame being navigated can be a RemoteFrame which will cause
the LocalFrame to be null and the HTTP Post will never be sent.

[Radar WebKit Bug Importer]

<rdar://problem/175786872>

[Anthony Tarbinian]

Pull request: https://github.com/WebKit/WebKit/pull/63852

[EWS]

Committed 312548@main (61696c58623d): <https://commits.webkit.org/312548@main>

Reviewed commits have been landed. Closing PR #63852 and removing active labels.