[Site Isolation] Synchronize useDarkAppearance of child frame's owner element
rdar://157145568
https://bugs.webkit.org/show_bug.cgi?id=309098

Reviewed by Ryosuke Niwa.

CSS Color Adjustment Module Level 1 [1] dictates that if the used color scheme of the
child frame's owner element is different than the used color scheme of the child frame,
the background of the child frame must be opaque and not transparent [2]:

> In order to preserve expected color contrasts, in the case of embedded documents typically
rendered over a transparent canvas (such as provided via an HTML iframe element), if the used
color scheme of the element and the used color scheme of the embedded document’s root element
do not match, then the UA must use an opaque canvas of the Canvas color appropriate to the
embedded document’s used color scheme instead of a transparent canvas.

This was implemented in 241325@main by checking useDarkAppearance of the child frame's owner
renderer. When Site Isolation is enabled and the child frame is cross-origin with the main frame,
this information isn't available, since the main frame's render tree (which contains the child
frame's owner renderer) is in a different process from the child frame process, therefore the
child frame can't check for this and draw the background opaque.

Fix this by synchronizing useDarkAppearance of the child frame's owner renderer using
RemoteFrameLayoutInfo, so that it's available in other processes too. Then the child frame's
process can access this info and make decision about drawing opaque background.

[1]: https://drafts.csswg.org/css-color-adjust/
[2]: https://drafts.csswg.org/css-color-adjust/#:~:text=In%20order%20to%20preserve%20expected%20color%20contrasts

Test: imported/w3c/web-platform-tests/css/css-color-adjust/rendering/dark-color-scheme/color-scheme-iframe-background-mismatch-opaque-cross-origin-002.sub.html

* LayoutTests/imported/w3c/web-platform-tests/css/css-color-adjust/rendering/dark-color-scheme/color-scheme-iframe-background-mismatch-opaque-cross-origin-001.sub-expected.html: Renamed from LayoutTests/imported/w3c/web-platform-tests/css/css-color-adjust/rendering/dark-color-scheme/color-scheme-iframe-background-mismatch-opaque-cross-origin.sub-expected.html.
* LayoutTests/imported/w3c/web-platform-tests/css/css-color-adjust/rendering/dark-color-scheme/color-scheme-iframe-background-mismatch-opaque-cross-origin-001.sub.html: Renamed from LayoutTests/imported/w3c/web-platform-tests/css/css-color-adjust/rendering/dark-color-scheme/color-scheme-iframe-background-mismatch-opaque-cross-origin.sub.html.
    - Change the iframe domain to a different TLD+1. WebKit site isolation considers a frame
      cross-origin only if its TLD+1 is different.

* LayoutTests/imported/w3c/web-platform-tests/css/css-color-adjust/rendering/dark-color-scheme/color-scheme-iframe-background-mismatch-opaque-cross-origin-002.sub-expected.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/css/css-color-adjust/rendering/dark-color-scheme/color-scheme-iframe-background-mismatch-opaque-cross-origin-002.sub.html: Added.
    - Add a new test, similar to color-scheme-iframe-background-mismatch-opaque-cross-origin-001.sub.html,
      but the main page is dark color-scheme, and child frame is light color-scheme.

* LayoutTests/imported/w3c/web-platform-tests/css/css-color-adjust/rendering/dark-color-scheme/support/light-frame.html: Added.
* LayoutTests/platform/glib/TestExpectations:
* Source/WebCore/page/Frame.cpp:
* Source/WebCore/page/FrameView.h:
* Source/WebCore/page/LocalFrameView.cpp:
(WebCore::LocalFrameView::ownerElementOfChildFrameUsesDarkAppearance const):
* Source/WebCore/page/LocalFrameView.h:
* Source/WebCore/page/Page.cpp:
(WebCore::Page::syncLocalFrameInfoToRemote):
* Source/WebCore/page/RemoteFrameLayoutInfo.h:
* Source/WebCore/page/RemoteFrameView.cpp:
(WebCore::RemoteFrameView::ownerElementOfChildFrameUsesDarkAppearance const):
* Source/WebCore/page/RemoteFrameView.h:
* Source/WebCore/rendering/RenderView.cpp:
(WebCore::RenderView::shouldPaintBaseBackground const):
* Source/WebKit/Shared/WebCoreArgumentCoders.serialization.in:

Canonical link: https://commits.webkit.org/308950@main
16 files changed
tree: c845a75e8febf78b788f0fe142188872e1af78b8
  1. .codex/
  2. .gemini/
  3. .github/
  4. Configurations/
  5. JSTests/
  6. LayoutTests/
  7. ManualTests/
  8. metadata/
  9. PerformanceTests/
  10. resources/
  11. Source/
  12. Tools/
  13. WebDriverTests/
  14. WebKit.xcworkspace/
  15. WebKitLibraries/
  16. Websites/
  17. .ccls
  18. .clang-format
  19. .dir-locals.el
  20. .editorconfig
  21. .gitattributes
  22. .gitignore
  23. .sourcefilters
  24. .submitproject
  25. .submitproject-tools
  26. .swift-format
  27. CMakeLists.txt
  28. CMakePresets.json
  29. Introduction.md
  30. Makefile
  31. Makefile.shared
  32. ReadMe.md
  33. vcpkg-configuration.json
  34. vcpkg.json
ReadMe.md

WebKit

WebKit is a cross-platform web browser engine. On iOS and macOS, it powers Safari, Mail, Apple Books, and many other applications. For more information about WebKit, see the WebKit project website.

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Getting the Code

Run the following command to clone WebKit's Git repository:

git clone https://github.com/WebKit/WebKit.git WebKit

You can enable git fsmonitor to make many git commands faster (such as git status) with git config core.fsmonitor true

Building WebKit

Building for Apple platforms

Install Xcode and its command line tools if you haven't done so already:

  1. Install Xcode Get Xcode from https://developer.apple.com/downloads. To build WebKit for OS X, Xcode 5.1.1 or later is required. To build WebKit for iOS Simulator, Xcode 7 or later is required.
  2. Install the Xcode Command Line Tools In Terminal, run the command: xcode-select --install

Run the following command to build a macOS debug build with debugging symbols and assertions:

Tools/Scripts/build-webkit --debug

For performance testing, and other purposes, use --release instead. If you also need debug symbols (dSYMs), run:

Tools/Scripts/build-webkit --release DEBUG_INFORMATION_FORMAT=dwarf-with-dsym 

Embedded Builds

To build for an embedded platform like iOS, tvOS, or watchOS, pass a platform argument to build-webkit.

For example, to build a debug build with debugging symbols and assertions for embedded simulators:

Tools/Scripts/build-webkit --debug --<platform>-simulator

or embedded devices:

Tools/Scripts/build-webkit --debug --<platform>-device

where platform is ios, tvos or watchos.

Using Xcode

You can open WebKit.xcworkspace to build and debug WebKit within Xcode. Select the “Everything up to WebKit + Tools” scheme to build the entire project.

If you don't use a custom build location in Xcode preferences, you have to update the workspace settings to use WebKitBuild directory. In menu bar, choose File > Workspace Settings, then click the Advanced button, select “Custom”, “Relative to Workspace”, and enter WebKitBuild for both Products and Intermediates.

Building the GTK Port

For production builds:

cmake -DPORT=GTK -DCMAKE_BUILD_TYPE=RelWithDebInfo -GNinja
ninja
sudo ninja install

For development builds:

Tools/gtk/install-dependencies
Tools/Scripts/update-webkitgtk-libs
Tools/Scripts/build-webkit --gtk --debug

For more information on building WebKitGTK, see the wiki page.

Building the WPE Port

For production builds:

cmake -DPORT=WPE -DCMAKE_BUILD_TYPE=RelWithDebInfo -GNinja
ninja
sudo ninja install

For development builds:

Tools/wpe/install-dependencies
Tools/Scripts/update-webkitwpe-libs
Tools/Scripts/build-webkit --wpe --debug

Building Windows Port

For building WebKit on Windows, see the WebKit on Windows page.

Running WebKit

With Safari and Other macOS Applications

Run the following command to launch Safari with your local build of WebKit:

Tools/Scripts/run-safari --debug

The run-safari script sets the DYLD_FRAMEWORK_PATH environment variable to point to your build products, and then launches /Applications/Safari.app. DYLD_FRAMEWORK_PATH tells the system loader to prefer your build products over the frameworks installed in /System/Library/Frameworks.

To run other applications with your local build of WebKit, run the following command:

Tools/Scripts/run-webkit-app <application-path>

iOS Simulator

Run the following command to launch iOS simulator with your local build of WebKit:

run-safari --debug --ios-simulator

In both cases, if you have built release builds instead, use --release instead of --debug.

To run other applications, for example MobileMiniBrowser, with your local build of WebKit, run the following command:

Tools/Scripts/run-webkit-app --debug --iphone-simulator <application-path>

Using Xcode

Open WebKit.xcworkspace, select intended scheme such as MobileMiniBrowser and an iOS simulator as target, click run.

Linux Ports

If you have a development build, you can use the run-minibrowser script, e.g.:

run-minibrowser --debug --wpe

Pass one of --gtk, --jsc-only, or --wpe to indicate the port to use.

Contribute

Congratulations! You’re up and running. Now you can begin coding in WebKit and contribute your fixes and new features to the project. For details on submitting your code to the project, read Contributing Code.