Listen to timeupdate on waiting

[gkatsev]

Description

This is to workaround a bug currently present in IE11 and potentially in
other cases where we get the waiting event and set the vjs-waiting
class on the player which shows the spinner but then we don't get any
of the events that we use to remove the spinner.
This fixes #3124.

Specific Changes proposed

Inside of handleTechWaiting_, listen to the first timeupdate event to clear the vjs-waiting class from the player.

Requirements Checklist

• Feature implemented / Bug fixed
• Reviewed by One Core Contributors

[dmlap]

Should we have a test for this? (Actual question)

[gkatsev]

I can try adding one.

[gkatsev]

@dmlap I added a simple test.

[dmlap]

LGTM

[mctep]

Hello! Thank you for your job.

May be it is better to trigger canplay event in html5 tech only for IE11 after waiting and timeupdate?

In my case I use https://github.com/google/shaka-player and it triggers timeupdate right after bufferingStart event. And spinner works incorrect after this fix. So I need to trigger waiting event in next tick:

class ShakaTech extends Tech {
 constructor() {
  // ...
  shakaPlayer.on('bufferingStart', () => {
    setTimeout(() => this.trigger('waiting'));
  })
  // ...
 }
}

It is not big problem. But I think it is not consistent and not obvious.