Validate item URL in BackForwardAddItem() IPC.
<rdar://98999288>
Pull request: https://github.com/WebKit/WebKit/pull/3866
Committed 254005@main (94716b7588d4): <https://commits.webkit.org/254005@main> Reviewed commits have been landed. Closing PR #3866 and removing active labels.
Reverted by https://github.com/WebKit/WebKit/pull/4833
Re-opening for pull request https://github.com/WebKit/WebKit/pull/4833
Committed 255005@main (7e840610aa3a): <https://commits.webkit.org/255005@main> Reviewed commits have been landed. Closing PR #4833 and removing active labels.
Re-opening for pull request https://github.com/WebKit/WebKit/pull/6568
Committed 256785@main (78a55cf3976c): <https://commits.webkit.org/256785@main> Reviewed commits have been landed. Closing PR #6568 and removing active labels.