Chrome flags are hidden settings for new browser features. Flags allow you to enable Chrome features that are being tested and yet to be released to the main channel. As in a test mode, these features are generally unstable. You can enable them if you want to try them out.
Every version update adds some ‘test’ features to regular channel and adds some new features to test mode. This article is updated regularly to track the latest flags of Chrome Canary channel. The outdated flags are removed and new flags are added regularly. How to Access the Google Chrome Flags page