In the recent releases of the Chromium behavior associated with the record in the exchange buffer. If in Firefox, Safari and the old Chrome issues, the record was allowed to be allowed only after the user’s obvious actions, then in the new issues for recording Enough just open the site. Changing behavior in Chrome is explained by the need to read data from an exchange buffer when displaying a screensaver google doodle on the opening page of a new tab (instead of a specific processing of this situations, Chromium simply allowed all sites to record in the exchange buffer without activating this operation by the user).
The ability to record works when calling navigator.clipboard.write ( example ) and navigator.clipboard.writetext (