Fix reboot for placeholder links

[ysds]

Fixes #28010

• native: https://codepen.io/anon/pen/eqdNVZ
  
• current: https://codepen.io/anon/pen/oKzXGG
  
• after: https://codepen.io/anon/pen/PMGqaX
  

[ysds]

I'm not sure should backport this to v4.

[XhmikosR]

Shouldn't we backport this?

[MartijnCuppens]

Yup. I would wait for @patrickhlauke's aproval before merging this, just to be sure.

[patrickhlauke]

so if it's a placeholder, but it has been explicitly made focusable with tabindex="0" or any tabindex value > 0, this would suppress any focus indication? if so, not sure i'd agree...focus needs to be shown somehow.

(edit: hover, not so much...don't particularly care for it either way...but focus definitely needs to be denoted if it's been made explicitly focusable)

[ysds]

@patrickhlauke The after behavior is:

Windows 10, Chrome 75

[XhmikosR]

This needs to be manually backported to v4-dev. Can someone do it in my v4-dev-xmr branch?

[patrickhlauke]

urgh only noticed now, should probably also amend the preceding comment in the scss that talks about tabindex... (see #29162)

[patrickhlauke]

This needs to be manually backported to v4-dev. Can someone do it in my v4-dev-xmr branch?

done #29162