[webkit-changes] [WebKit/WebKit] 2f9b54: Correct which element scrollbar-width is resolved ...

[Luke Warlow]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 2f9b54657be4231f239ac8bc8e46394f1848fae4
      https://github.com/WebKit/WebKit/commit/2f9b54657be4231f239ac8bc8e46394f1848fae4
  Author: Luke Warlow <luke at warlow.dev>
  Date:   2023-05-27 (Sat, 27 May 2023)

  Changed paths:
    A LayoutTests/imported/w3c/web-platform-tests/css/css-scrollbars/scrollbar-width-009-expected.txt
    A LayoutTests/imported/w3c/web-platform-tests/css/css-scrollbars/scrollbar-width-009.html
    M LayoutTests/platform/ios-wk2/TestExpectations
    M Source/WebCore/page/LocalFrameView.cpp

  Log Message:
  -----------
  Correct which element scrollbar-width is resolved from for the viewport
https://bugs.webkit.org/show_bug.cgi?id=257424

Reviewed by Tim Nguyen.

A new WPT test has been added which tests to make sure the body style doesn't propagate (like scrollbar-width-008.html) but runs in quirks mode. That passes inside of
Chrome (with appropriate flags), and Firefox but not WebKit (before this change).

When in quirks mode scrollingElement resolves to body, whereas in standards mode it resolves to documentElement.

I originally had this using documentElement but it was changed during the review process for WebKit 2 implementation. Based on the interop issue caught by the new
test I've made I believe I was originally correct and this should be documentElement.

This change addresses that changing scrollingElement back to documentElement.

* LayoutTests/imported/w3c/web-platform-tests/css/css-scrollbars/scrollbar-width-009-expected.txt: Added.
* LayoutTests/imported/w3c/web-platform-tests/css/css-scrollbars/scrollbar-width-009.html: Added.
* LayoutTests/platform/ios-wk2/TestExpectations:
* Source/WebCore/page/LocalFrameView.cpp:
(WebCore::LocalFrameView::scrollbarWidthStyle const):

Canonical link: https://commits.webkit.org/264632@main