Last week Google released a new beta version of Chrome with an integrated PDF viewer:
With the integrated Chrome PDF viewer now available in Chrome’s beta, you can open a PDF document in Chrome without installing additional software. The PDF document will load as quickly and seamlessly as a normal web page in the browser.
Just like we do with web pages viewed in Chrome, we’ve built in an additional layer of security called the “sandbox” around the Chrome PDF viewer to help protect you from malware and security attacks that are targeted at PDF files. For now, the Chrome PDF viewer is available only in the beta channel, but we look forward to adding more polish and features, as well as making it widely available in the stable channel soon.