Google Chrome   66.0.3376.0 (Official Build) dev  
Platform        10519.0.0 (Official Build) dev-channel 
JavaScript      V8 6.7.106
Flash   29.0.0.134

What steps will reproduce the problem?
(1)Get in go.cnn.com and sign in with account
(2)Watching CNN Live and switch to full screen
(3)Observed issue, the video screen become black

What is the expected result?
Should not have black screen

What happens instead?
the video screen become black

Feedback:
Report ID: 85235875569


*********Note********
1. Issue reproduce on M-66 beta
2. Issue no reproduce on M-65