We can see that the “Chrome OS Dev Channel” has been updated to version 50.0.2661.20 here.
The Developer channel of Chrome OS has been updated to version 50.0.2661.20. The current version of the Platform is 7978.10, which includes enhancements, enhancement patches, and security upgrades. In addition, this update was rolled out to all Chrome OS devices with the exception of the Asus Chromebook C200.
There have been a lot of changes made in this update, and if you want to know what they are, you can check out the changelog for the version 50.0.2661.20 here on this page.