Player stops instead of reproducing next video when you change browser tab

Live example: http://codepen.io/hone/pen/dYKjro

Two videos, first ends, second starts.
But let's switch to another browser tab before the first video ends, player will pause and second video will never start until you come back to the previous tab.

The issue affects at least chrome and safari (not tested on IE), but works fine on firefox.

Start with the live CodePen example and reproduce the behavior by switching tabs before the first video ends. Compare Chrome and Safari with Firefox, then verify that the second video starts without returning to the original tab.

Written by the indexing model from the issue text.