https://groups.google.com/a/chromium.org/forum/#!topic/experimentation-dev/GsPtuFt8XqA Seems the idea is to allow a limited number of web developers/sites to access experimental features/APIs in the browser. Said developers/sites will have to acquire an API key that they will pass to the visitor's browser via meta header. I didn't dig into the subject to see if they are intending to allow users to disable the behavior.