A little more than two years ago, engineers on the Chrome team began a very ambitious project. In coordination with Adobe, we started porting Flash from the aging NPAPI architecture to our sandboxed PPAPI platform. With last weeks Chrome Stable release, we were finally able to ship PPAPI Flash to all Windows Chrome users. For the first time ever, Windows XP users (specifically, over 100 million Chrome users) have a sandboxed Flashwhich is critical given the absence of OS support for security features.”]
Source: https://blog.chromium.org/2012/08/the-road-to-safer-more-stable-and.html