For example, this page example In dev tools console errors are shown, for each video, like this
OPTIONS http://material-design.storage.googleapis.com/videos/animation-authentic-motion-authenticMotion_massAndWeight_ex1_large_xhdpi.webm Origin hxxp://www.google.com is not allowed by Access-Control-Allow-Origin. authentic-motion.html:1
If link on video in console clicked, video played at new page. In firefox all is ok - all the videos playing as embedded as intended.
Adblock and flashblock plugins were disabled but this did not help. I have read about this error - this is security protection feature, but why this is error on google site? And how to tweak/whitelist site?