About:Flags or chrome://flags is a url in Chrome that allows you to try new features in Chrome while they are being tested or are generally unstable. You can enable them as you want. And even when you load up a guest session they are still loaded. Just as disclaimer. The page puts it best "WARNING These experimental features may change, break, or disappear at any time. We make absolutely no guarantees about what may happen if you turn one of these experiments on, and your browser may even spontaneously combust. Jokes aside, your browser may delete all your data, or your security and privacy could be compromised in unexpected ways. Any experiments you enable will be enabled for all users of this browser. Please proceed with caution."