This warning will be displayed for any download URL that matches the latest list of malicious websites published by the Safe Browsing API. The new feature follows the same privacy policy currently in use by the Safe Browsing feature. For example, this feature does not enable Google to determine the URLs you are visiting.
We’re starting with a small-scale experimental phase for a subset of our users who subscribe to the Chrome development release channel, and we hope to make this feature available to all users in the next stable release of Google Chrome. We hope that the feature will improve our users’ online experience and help make the Internet a safer place.
For webmasters, you can continue to use the same interface provided by Google Webmaster Tools to learn about malware issues with your sites. These tools include binaries that have been identified by this new feature, and the same review process will apply.