[webkit-changes] [WebKit/WebKit] 903fc9: REGRESSION(257538 at main): CSS opacity doesn't work ...

[Tim Nguyen]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 903fc90f8a6a2d9b9f6bcc5951967b2aab11344d
      https://github.com/WebKit/WebKit/commit/903fc90f8a6a2d9b9f6bcc5951967b2aab11344d
  Author: Tim Nguyen <ntim at apple.com>
  Date:   2023-02-20 (Mon, 20 Feb 2023)

  Changed paths:
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/modal-dialog-backdrop-opacity-expected.html
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/modal-dialog-backdrop-opacity-ref.html
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/modal-dialog-backdrop-opacity.html
    M Source/WebCore/rendering/RenderLayerBacking.cpp

  Log Message:
  -----------
  REGRESSION(257538 at main): CSS opacity doesn't work on dialog::backdrop
https://bugs.webkit.org/show_bug.cgi?id=252536
rdar://105636947

Reviewed by Simon Fraser.

The background layer functionality is to avoid flashes of white when rotating the screen on mobile device.
However, it breaks the opacity property, so only restrict it to the fullscreen element's backdrop, which is the only main
case that needs this polish (e.g. rotating while watching a fullscreen video).

* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/modal-dialog-backdrop-opacity-expected.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/modal-dialog-backdrop-opacity-ref.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/modal-dialog-backdrop-opacity.html: Added.
* Source/WebCore/rendering/RenderLayerBacking.cpp:
(WebCore::RenderLayerBacking::RenderLayerBacking):

Canonical link: https://commits.webkit.org/260556@main