The Netscape Plugin API (NPAPI) architecture extends all the way back to Netscape Navigator 2.0, but, starting next year, Google will begin to phase out all plugins, apps, and extensions that make use of the interface.
From January 2014, Chrome will block "webpage-instantiated NPAPI plugins" as the default action, unless the plugin is on a temporary whitelist of the most used NPAPI plugins.
The plugins on the whitelist will be Silverlight, Unity, Google Earth, Google Talk, and Facebook Video. Even though Java is in the top five most popular plugins used, it will maintain its current status of being blocked for security reasons.
Google says that the above six plugins are the only NPAPI plugins that were used by more than 5 percent of users in the last month. IT administrators and users will be able to whitelist any other plugins that they wish.
Read more at: Chrome puts NPAPI plugins on death watch | ZDNet