main frame - didStartProvisionalLoadForFrame
main frame - didCommitLoadForFrame
main frame - didFinishDocumentLoadForFrame
frame "<!--frame1-->" - didStartProvisionalLoadForFrame
127.0.0.1:8000 - didReceiveAuthenticationChallenge - ProtectionSpaceAuthenticationSchemeHTTPBasic - Responding with webkit:rocks
frame "<!--frame1-->" - didCommitLoadForFrame
frame "<!--frame1-->" - didFinishDocumentLoadForFrame
frame "<!--frame1-->" - willPerformClientRedirectToURL: http://127.0.0.1:8000/a//b/non-existent-file.html 
frame "<!--frame1-->" - didHandleOnloadEventsForFrame
main frame - didHandleOnloadEventsForFrame
frame "<!--frame1-->" - didFinishLoadForFrame
main frame - didFinishLoadForFrame
frame "<!--frame1-->" - didStartProvisionalLoadForFrame
frame "<!--frame1-->" - didCancelClientRedirectForFrame
frame "<!--frame1-->" - didCommitLoadForFrame
frame "<!--frame1-->" - didReceiveTitle: 404 Not Found
frame "<!--frame1-->" - didFinishDocumentLoadForFrame
frame "<!--frame1-->" - didFailLoadWithError
PASS did not cause assertion failure.