The `overflow-*` values of either the root element or the `<body>` get
propagated to the viewport. However, we were missing this part:
> The element from which the value is propagated must then have a used
`overflow` value of `visible`.
See https://drafts.csswg.org/css-overflow/#overflow-propagation
Testing:
- `css/cssom-view/scrolling-quirks-vs-nonquirks.html`
- `css/css-overflow/overflow-body-propagation-007.html`
- `css/css-overflow/overflow-body-propagation-008.html`
- `css/css-overflow/overflow-body-propagation-009.html`
- `css/css-overflow/scrollable-overflow-with-nested-elements-001.html`
- `css/css-overflow/scrollable-overflow-with-nested-elements-002.html`
- `css/css-overflow/scrollable-overflow-with-nested-elements-003.html`
- `css/css-overflow/scrollable-overflow-with-nested-elements-004.html`
- `css/css-overflow/scrollbar-gutter-scroll-into-view.html`
Failures:
- `css/css-overflow/overflow-body-propagation-010.html`
Failing because of missing support for `contain: paint`.
- `css/css-overflow/scrollable-overflow-with-nested-elements-005.html`
Failing because of wrong `data-expected-height`, but correct
`data-expected-scroll-height` which is core of this PR.
`data-expected-height` can be dealt separately.
Fixes: #38248
---------
Signed-off-by: Shubham Gupta <shubham13297@gmail.com>
Signed-off-by: Oriol Brufau <obrufau@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
