Select value is highlighted in IE on focus

[acdvorak]

What MDC Web Version are you using?

0.39.1

What browser(s) is this bug affecting?

IE 11 💩

What OS are you using?

Windows 10

What are the steps to reproduce the bug?

1. View the mdc-select screenshot test page in IE 11

What is the expected behavior?

Select value should have black text and a transparent background when focused:

What is the actual behavior?

Select value has white text (#ffffff) and a blue background (#3a9bfc) when focused:

Sometimes, just for fun, IE renders a slightly darker blue (#137ad4):

Any other information you believe would be useful?

The flaky blue background color (#3a9bfc vs. #137ad4 on an Apple Thunderbolt Display)
causes spurious screenshot diffs. E.g.:

• PR chore(infrastructure): Upload captured images to master report #3501:
  • Report 2018-09-03T00:03:31.368Z
  • Report 2018-09-03T00:40:58.983Z
  • Report 2018-09-03T01:11:04.043Z
• PR feat(checkbox): Support customizing the color of the stroke in the marked state #3412:
  • Report 2018-08-31T23:16:24.685Z
• PR chore(select): Add screenshot tests #3434:
  • Report 2018-09-04T03:26:55.129Z

Fixing it should be as simple as:

.mdc-select__native-control::-ms-value {
  background-color: transparent;
  color: inherit;
}