[Slider] Value label position if disabled

If the Slider is disabled, the value label is slightly off to the right.

• The issue is present in the latest release.
• I have searched the issues of this repository and believe that this is not a duplicate.

Current Behavior 😯

The value label for a disabled Slider is positioned slightly to the right.

The problem is at this line: https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Slider/ValueLabel.js#L23 Removing the line fixed the problem, can you explain why it is needed?

Expected Behavior 🤔

The value label should be centered.

Steps to Reproduce 🕹

https://codesandbox.io/s/material-demo-edpse

Steps:

1. Use valueLabelDisplay="on" to make the value label visible all the time
2. Use disabled={true}

Context 🔦

I want to display the value of a disabled slider.

Your Environment 🌎

Tech	Version
Material-UI	v4.8.3

[davidfdriscoll]

That sounds good – would you mind if I try tackling that and submit a pull request to remove the IE 11 fix and add a test?

[oliviertassinari]

@davidfdriscoll Please do 😃