At the request of many developers, Google allows the use of Chrome extensions from outside the Chrome Web Store until may 1. Originally it would be from 1 January will no longer be possible to manually select the extensions to add to the Windows version of Chrome.
Google on the Chromium Blog that, some developers said they needed more time to have to 
the transition to the Chrome Web Store to make. The search giant maintains the policy already on the Chrome Beta Channel. From 1 may it will no longer be possible in the stable version manually extensions to add. In addition, turn Google from that date automatically all the extensions that are already installed, but not in the Chrome Web Store.
The search giant announced the measure in november. Windows-users would be much affected by unwanted extensions that, for example, the home page, hijack, or malware, and ads serving. The measure applies only to the Windows version: on Mac, Linux and Chrome OS, nothing has changed.