To get access to the new security feature, head to chrome://flags and look for "safe browsing." You need to activate these two flags:
Once enabled, head to settings and look for the new Privacy and security section replacing the Privacy only entry of old. In there, you'll find a new Safe Browsing UI that lets you choose between standard and enhanced protection. Like on the current stable desktop version, you can select your preferred level right here, but you can also tap the arrow next to both entries to learn more about the options.
Google says that this new measure increases security by about 20% on desktops and 25% on mobile.