NetErrorTabHelper currently listens for the DidStartProvisionalLoadForFrame() and DidFailProvisionalLoad() WebContentsObserver callbacks. However, these callbacks are deprecated and cannot be relied on when PlzNavigate is enabled. NetErrorTabHelper should migrate to listening for DidStartNavigation() and DidFinishNavigation().

This bug is the cause of several browser_tests failures when run with PlzNavigate enabled:

DnsProbeBrowserTest.CorrectionsLoadStopped
DnsProbeBrowserTest.NoInternetProbeResultWithBrokenCorrections
ErrorPageNavigationCorrectionsFailTest.FetchCorrectionsFails
DnsProbeBrowserTest.NxdomainProbeResultWithWorkingSlowCorrections
ErrorPageTest.IFrameDNSError_JavaScript
DnsProbeBrowserTest.CorrectionsDisabled
DnsProbeBrowserTest.CorrectionsLoadStoppedSlowProbe
DnsProbeBrowserTest.ProbesDisabled
DnsProbeBrowserTest.SyncFailureWithBrokenCorrections
DnsProbeBrowserTest.NoInternetProbeResultWithSlowBrokenCorrections
DnsProbeBrowserTest.Incognito
DnsProbeBrowserTest.NxdomainProbeResultWithWorkingCorrections