"Google Chrome 54" stable release, promoting the transition from Flash to HTML5
The latest stable version "54.0.2840.59" of web browser "Google Chrome" has been released for Windows, Mac and Linux. In addition to newly added features for developers, changes such as rewriting embedded tags in YouTube's Flash Player format to HTML5 format have been added.
Chrome Releases: Stable Channel Update for Desktop
https://googlechromereleases.blogspot.jp/2016/10/stable-channel-update-for-desktop.html
YouTube's embedded tags are in Flash Player format (