"When enabled, Chrome's data compression and bandwidth management can reduce data usage by up to 50% while browsing the web on Chrome for Android and iOS. This feature also enables Chrome's Safe Browsing technology which helps protect you from malicious webpages," informs Google.
This feature uses a Google proxy to compress all the pages you visit, except for HTTPS pages and the sites you visit in Chrome's incognito mode.
Chrome for iOS also adds the page translation feature, which was previously limited to Chrome for Android and desktop, while Chrome for Android lets you add to the homescreen shortcuts to any page or web app.
As usually, "these updates will be rolling out over the next few days", so don't expect to get the latest version of Mobile Chrome right away.