Created attachment 8716939 [details] Screen Shot 2016-02-08 at 16.48.11.png 1. Go to youtube.com and play a video in portrait mode 2. Switch to landscape 3. Press on 'Done' to exit full screen (sometimes the bug manifests at this step) 4. Switch to portrait Result: The viewport is incorrect. Please see the attached screenshot.
Not reproducible in Safari.
Tested on latest master and this issue is no longer reproducible