Fix texttrack handling in IE10

[nickygerritsen]

Apparantly IE10 does have textTracks on the video element, but does not support addEventListener and removeEventListener on it.

This should fix that problem.

[gkatsev]

haha, I had that in my code but removed it. Does IE10 allow for us to listen for events on the textTracks? Or does it also not support it? In which case, we should disable it like we did IE10.

[nickygerritsen]

IE10 gives undefined for tt.addEventListener (and also for the remove). So I think we should remove it

[gkatsev]

is onremovetrack or onaddtrack available on the element?

[nickygerritsen]

Oh just left work so I can only check much later

[heff]

Bah...I told @gkatsev to remove the check. My bad!

[nickygerritsen]

I tried to figure out if onaddtrack and onremovetrack are there, but both in IE and in Chrome if I output vid.textTracks.onaddtrack in the console I get nothing, so not really sure how to find out if this exists.

[gkatsev]

If IE outputs nothing a falsey value for 'onremovetrack' in vid.textTracks, then we should already be disabling native functionality (https://github.com/videojs/video.js/blob/master/src/js/tech/html5.js#L896-L898). Though, I guess we still need this because we might still be trying to bind and unbind the handlers.

[heff]

lgtm

[gkatsev]

Thanks.