Bug 246338 – [css-contain-intrinsic-size] Apply the value of css contain-intrinsic-size to <select>

• Component: CSS
• Status: RESOLVED FIXED

[cathiechen]

`<select>` adjust the style in RenderThemeMac::adjustMenuListStyle, which might change auto values of width and height to fixed values in the style.
The values of contain-intrinsic-size specify an explicit intrinsic inner size of <select>, which does not affect the layout size of <select> if there are fixed width and height.
We should found a way to make contain-intrinsic-size effective to <select>.

See test case: LayoutTests/imported/w3c/web-platform-tests/css/css-sizing/contain-intrinsic-size/contain-intrinsic-size-032.html

[Radar WebKit Bug Importer]

<rdar://problem/101290328>

[cathiechen]

The case 1 fails because `border: solid;` changes `part` from `MenulistPart` to `MenulistButtonPart` in `RenderTheme::adjustStyle`.
Then it goes different path:

```
    case MenulistPart:
        return adjustMenuListStyle(style, element);
    case MenulistButtonPart:
        return adjustMenuListButtonStyle(style, element);
```
After style adjust, the appearance is different.

It seems WebKit is using `RenderStyle::borderAndBackgroundEqual` to decide which appearance. I'm not sure if we should touch this part.

[cathiechen]

Created attachment 463194 [details]
WIP-patch

This patch is based on https://github.com/WebKit/WebKit/pull/1799.
We can merge this easily, but the patch on 1799 is very large now, So I make this a separating patch.

[cathiechen]

Pull request: https://github.com/WebKit/WebKit/pull/5868

[EWS]

Committed 257704@main (b7276669eb69): <https://commits.webkit.org/257704@main>

Reviewed commits have been landed. Closing PR #5868 and removing active labels.