bf-cache always fails in headless mode

[adamraine]

With --chrome-flags"--headless":

[dwsmart]

Running in the new headless mode seems to fix this, so changing

const chrome = await chromeLauncher.launch({chromeFlags: ['--headless']});

to

const chrome = await chromeLauncher.launch({chromeFlags: ['--headless=new']});

Seems to solve the window.open() issue:

[adamraine]

I doubt the old headless Chrome will every support bfcache testing, so we shouldn't consider this a bug. That being said, we should warn the user when the results are foobar and/or mark the audit as n/a.

[Yogurt4]

That being said, we should warn the user when the results are foobar and/or mark the audit as n/a.

Agreed. Lighthouse gives me a "Page prevented back/forward cache restoration" fail. Testing it with Chrome DevTools gives "Successfully served from back/forward cache." though.