Chrome Version: 61.0.3135.4
OS: Linux

on Chrome 59.0.3071.109 release build, frame drop rate is about 6~7%, on Chrome 61.0.3135.5 dev build, it jump to 15%.

What steps will reproduce the problem?
(1) navigate to https://www.youtube.com/watch?v=_fC53l3jGAc
(2) switch to highest resolution 4k 

What is the expected result?
considering it is 4k video, some drop rate is expected, but it need be reasonable.

What happens instead?
15% drop rate