[webkit-changes] [WebKit/WebKit] 1b3e49: [css-content] AX: Add support for alt text syntax

[Tim Nguyen]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 1b3e497426196dd3289ad58811bdb12cbaa29379
      https://github.com/WebKit/WebKit/commit/1b3e497426196dd3289ad58811bdb12cbaa29379
  Author: Tim Nguyen <ntim at apple.com>
  Date:   2023-12-22 (Fri, 22 Dec 2023)

  Changed paths:
    M LayoutTests/imported/w3c/web-platform-tests/accname/name/comp_name_from_content-expected.txt
    M LayoutTests/imported/w3c/web-platform-tests/accname/name/comp_name_from_content.html
    M Source/WebCore/css/CSSValuePair.cpp
    M Source/WebCore/css/CSSValuePair.h
    M Source/WebCore/css/parser/CSSPropertyParserHelpers.cpp
    M Source/WebCore/style/StyleBuilderCustom.h

  Log Message:
  -----------
  [css-content] AX: Add support for alt text syntax
https://bugs.webkit.org/show_bug.cgi?id=159022
rdar://26942023

Reviewed by Darin Adler.

This adds support for the `content: "foo" / "alt-text";` syntax. Multiple strings / attr() functions can also be chained.

Counters are not supported by this PR. Other non-text types are intentionally not supported as alt-text per-spec.

Spec: https://drafts.csswg.org/css-content-3/#alt

* LayoutTests/imported/w3c/web-platform-tests/accname/name/comp_name_from_content.html:
* LayoutTests/imported/w3c/web-platform-tests/accname/name/comp_name_from_content-expected.txt:
* Source/WebCore/css/CSSValuePair.cpp:
(WebCore::CSSValuePair::CSSValuePair):
(WebCore::CSSValuePair::create):
(WebCore::CSSValuePair::createSlashSeparated):
(WebCore::CSSValuePair::createNoncoalescing):
* Source/WebCore/css/CSSValuePair.h:
* Source/WebCore/css/parser/CSSPropertyParserHelpers.cpp:
(WebCore::CSSPropertyParserHelpers::consumeContent):
* Source/WebCore/style/StyleBuilderCustom.h:
(WebCore::Style::BuilderCustom::applyValueContent):

Canonical link: https://commits.webkit.org/272455@main