[webkit-changes] [WebKit/WebKit] 79d2de: Add shadowrootclonable and align with declarative ...

[Anne van Kesteren]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 79d2dec92caef6f7df33125ab34bd70e36c982c2
      https://github.com/WebKit/WebKit/commit/79d2dec92caef6f7df33125ab34bd70e36c982c2
  Author: Anne van Kesteren <annevk at annevk.nl>
  Date:   2024-02-15 (Thu, 15 Feb 2024)

  Changed paths:
    M LayoutTests/imported/w3c/web-platform-tests/scroll-animations/css/scroll-timeline-name-shadow.html
    M LayoutTests/imported/w3c/web-platform-tests/scroll-animations/css/view-timeline-name-shadow.html
    M LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-attachment-expected.txt
    M LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-basic-expected.txt
    A LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-repeats-2-expected.txt
    A LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-repeats-2.html
    M LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-repeats-expected.txt
    M LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-repeats.html
    M LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/w3c-import.log
    M LayoutTests/imported/w3c/web-platform-tests/shadow-dom/shadow-root-clonable-expected.txt
    M Source/WebCore/dom/Element.cpp
    M Source/WebCore/dom/Element.h
    M Source/WebCore/html/HTMLAttributeNames.in
    M Source/WebCore/html/HTMLTemplateElement.cpp
    M Source/WebCore/html/parser/HTMLConstructionSite.cpp

  Log Message:
  -----------
  Add shadowrootclonable and align with declarative shadow root changes
https://bugs.webkit.org/show_bug.cgi?id=269361

Reviewed by Ryosuke Niwa.

This makes the following changes:

- Adds the new shadowrootclonable attribute to opt into a declarative
  shadow root being clonable.
- As a result, declarative shadow roots are no longer clonable by
  default. Web developers will have to explicitly opt in.
- When attachShadow() is called on a shadow host with an existing
  declarative tree, throw if mode is a mismatch.
- In attachShadow() throw first for mode being set to "user-agent" as
  this is to be caught by the binding layer in theory.
- And finally, only attach a declarative shadow root successfully for
  the first template element.

New tests are upstreamed here:
https://github.com/web-platform-tests/wpt/pull/44568

Specification changes are here (not all have landed yet as various nits
are still being addressed, but all have agreement):

- https://github.com/whatwg/html/pull/10117
- https://github.com/whatwg/html/pull/10069
- https://github.com/whatwg/dom/pull/1246

* LayoutTests/imported/w3c/web-platform-tests/scroll-animations/css/scroll-timeline-name-shadow.html:
* LayoutTests/imported/w3c/web-platform-tests/scroll-animations/css/view-timeline-name-shadow.html:
* LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-attachment-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-basic-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-repeats-2-expected.txt: Added.
* LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-repeats-2.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-repeats-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/declarative-shadow-dom-repeats.html:
* LayoutTests/imported/w3c/web-platform-tests/shadow-dom/declarative/w3c-import.log:
* LayoutTests/imported/w3c/web-platform-tests/shadow-dom/shadow-root-clonable-expected.txt:
* Source/WebCore/dom/Element.cpp:
* Source/WebCore/dom/Element.h:
* Source/WebCore/html/HTMLAttributeNames.in:
* Source/WebCore/html/HTMLTemplateElement.cpp:
(WebCore::HTMLTemplateElement::attachAsDeclarativeShadowRootIfNeeded):
* Source/WebCore/html/parser/HTMLConstructionSite.cpp:
(WebCore::HTMLConstructionSite::insertHTMLTemplateElement):

Canonical link: https://commits.webkit.org/274727@main