Fix: changes 'mousedown' to the 'mouseup' event in the player

[gjanblaszczyk]

Description

All buttons in the player use 'mouseup' instead of 'mousedown' event.
This player behavior is very useful for accessibility because the user can cancel the action by clicking outside the button area.
However, in the player, there is one place that the player uses a 'mousedown' instead of 'mouseup' event. I think that is just a mistake.
You can check it by clicking on the video area during the playback. You will see that the playback pauses/resumes after 'mousedown' event but if you click on the play/pause button over the controlbar it uses 'mouseup' event.
The WCAG 2.1 "2.5.2 Pointer Cancellation" spec. also suggests using "mouseup" instead of "mousedown" event.

Specific Changes proposed

I changed "mousedown' to 'mouseup" event inside the player.

Requirements Checklist

• Feature implemented / Bug fixed
• If necessary, more likely in a feature request than a bug fix
  • Change has been verified in an actual browser (Chome, Firefox, IE)
  • Unit Tests updated or fixed
  • Docs/guides updated
  • Example created (starter template on JSBin)
• Reviewed by Two Core Contributors

[gkatsev]

Yeah, switching to mouseup is probably best unless it ends up breaking something, though, I can't imagine it will.

[OwenEdwards]

Looks like you also need to change the comment/documentation at:

video.js/src/js/player.js

Line 1848 in 57dbf0e

* @listens Tech#mousedown

@Listens Tech#mouseup

[OwenEdwards]

LGTM

[gkatsev]

Thanks for helping improve the accessibility of Video.js @gjanblaszczyk!

[gjanblaszczyk]

Thanks @gkatsev