Bug 1880374 - Disable DNS prefetching if document nodePrincipal is systemPrincipal r=valentin

}

bool HTMLDNSPrefetch::IsAllowed(Document* aDocument) {

  // Do not use prefetch if the document's node principal is the system

  // principal.

  nsCOMPtr<nsIPrincipal> principal = aDocument->NodePrincipal();

  if (principal->IsSystemPrincipal()) {

    return false;

  }

  // There is no need to do prefetch on non UI scenarios such as XMLHttpRequest.

  return aDocument->IsDNSPrefetchAllowed() && aDocument->GetWindow();

}