Google Chrome will shortly be able to detect and block downloads of malware.
This functionality become available in Google Chrome Canary.
The malware detection is based on the safebrowsing program.
The new browser can be tested via: https://www.google.com/intl/nl/chrome/browser/canary.html
Info related safe browsing program:
https://googleonlinesecurity.blogspot.be/2013/06/transparency-report-making-web-safer.html