Google has announced a new Enhanced Safe Browsing feature that will offer real-time protection against known malicious web sites and downloads. Google Chrome uses the feature by downloading lists of known malicious sites and saving them locally. Chrome checks the URL of each site you visit or file you download against a local list, which is updated approximately every 30 minutes. Chrome will also send a small sample of pages and suspicious downloads to help discover new threats against you and other Chrome users. If you are signed into Chrome and are using the feature, the transferred data is linked to your Google account to detect if an attack if targeting your browser or account.
Source: https://www.bleepingcomputer.com/news/google/google-rolls-out-new-enhanced-safe-browsing-security-feature/