r460581 make browser initiated navigations don't go to the renderer first, unless the browser knows that the previous page had a beforeunload handler. This did change timing, which caused other failures. All the other failures were test bugs or code bugs. I'm fairly confident there's no underlying bug in plznavigate that was added from that.

I suspect with WebNavigationApiTest.ForwardBack the bug is in the webnavigation code, since the test is pretty simple.

Nasko: can you help take a look at this? It repros locally on Windows release builds (but not debug, or any builds on Linux)