Chromium Version       : 57.0.2979.0

What steps will reproduce the problem?
1. Enable experimental flag chrome://flags/#video-fullscreen-orientation-lock
2. Go to http://camendesign.com/code/video_for_everybody/test.html
3. Play video
4. Enter fullscreen
5. It's awesome! 
6. Exit fullscreen

What is the expected result?
Web page should be the same as before.

What happens instead of that?
Viewport has changed ;( See video attached.
 

Deleted: fullscreen.mp4 6.3 MB

	fullscreen.mp4 6.3 MB View Download