[webkit-changes] [WebKit/WebKit] 2bf7fb: `contain:content` on the body breaks scrolling

[Rob Buis]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 2bf7fb96494b9ccf14e3e6d26c054419eb44ced4
      https://github.com/WebKit/WebKit/commit/2bf7fb96494b9ccf14e3e6d26c054419eb44ced4
  Author: Rob Buis <rbuis at igalia.com>
  Date:   2022-09-15 (Thu, 15 Sep 2022)

  Changed paths:
    A LayoutTests/imported/w3c/web-platform-tests/css/css-contain/contain-paint-050-expected.html
    A LayoutTests/imported/w3c/web-platform-tests/css/css-contain/contain-paint-050-ref.html
    A LayoutTests/imported/w3c/web-platform-tests/css/css-contain/contain-paint-050.html
    M Source/WebCore/page/FrameView.cpp

  Log Message:
  -----------
  `contain:content` on the body breaks scrolling
https://bugs.webkit.org/show_bug.cgi?id=244989

Reviewed by Simon Fraser.

Do not take paint containment into account when deciding
whether the viewport scrollbars needs to be enabled.

Behavior matches Firefox and Chrome.

* LayoutTests/imported/w3c/web-platform-tests/css/css-contain/contain-paint-050-expected.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/css/css-contain/contain-paint-050-ref.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/css/css-contain/contain-paint-050.html: Added.
* Source/WebCore/page/FrameView.cpp:
(WebCore::FrameView::applyOverflowToViewport):

Canonical link: https://commits.webkit.org/254506@main