Experimental Chromium Web Platform Features

Support box-decoration-break:clone both for inline fragmentation (line layout) and block fragmentation (pagination for printing, multicol). Traditionally in Blink, only box-decoration-break:slice (the initial value) has been supported for block fragmentation, whereas for inline fragmentation, box-decoration-break:clone was also supported, but only when using the prefixed -webkit-box-decoration-break property. See https://drafts.csswg.org/css-break/#break-decoration

This feature is not to fire selectionchange event when there is already one pending. For web developers, selectionchange event listeners will be called less often with this feature. Before this feature, every time the mutation of the selection on one target(input/textarea/document) would make the listener to be called once. Now with this feature, before the selectionchange event listner is finally called, multiple mutations of the selection on one target would make the listener to be called only once.

Adds a Controlled Frame API available only to Isolated Web Apps (IWAs). This work will add a new Controlled Frame API which is only available to Isolated Web Apps (IWAs). Like similarly-named APIs on other platforms, Controlled Frame allows embedding all content, even third party content that can't be embedded in <iframe>. Controlled Frame also allows controlling embedded content with a collection of API methods and events. For more info on Isolated Web Apps, see the IWA explainer: https://github.com/WICG/isolated-web-apps/blob/main/README.md

Replaces the inset-area() function with inset-area values directly within position-try-fallbacks. This means that you now just write e.g. position-try-fallbacks:top instead of position-try-fallbacks:inset-area(top).

The reading-flow CSS property controls the order in which elements in a flex or grid layout are rendered to speech or are navigated to when using (linear) sequential navigation methods. This feature implements the listed values: * normal * flex-visual * flex-flow * grid-rows * grid-columns * grid-order

This feature allows scrollIntoView with behavior: "smooth" to run concurrently on scroll containers which are neither descendants nor ancestors of one another. scrollIntoView with behavior: "smooth" is a JavaScript method developers can use to cause scroll containers to scroll to their descendants via a gentle scroll animation. This feature fixes Chrome's implementation of the API so that ongoing scrollIntoView animations are not cancelled by unrelated scrolls on other scroll containers. This codepen[1] demonstrates the difference in behavior between Chrome and other browsers. The features also fixes cases where Chrome fails to scroll to a page's fragment anchor because of a competing scrollIntoView that is invoked when the page loads. [1] https://codepen.io/awogbemila/pen/GRaJQMG

Adds tone mapping parameters to the WebGPU canvas configuration, and adds options of "standard" (the current behavior of restricting content to the SDR range of the display) as the default, and "extended" (not imposing this restriction) as a new behavior. This allows WebGPU content to use the full range of a display.

Websites can and do get credentials from mobile wallet apps through a variety of mechanisms today (custom URL handlers, QR code scanning, etc.). This Web Platform feature would allow sites to request identity information from wallets via Android's IdentityCredential CredMan system. It is extensible to support multiple credential formats (eg. ISO mDoc and W3C verifiable credential) and allows multiple wallet apps to be used. Mechanisms are being added to help reduce the risk of ecosystem-scale abuse of real-world identity (see https://docs.google.com/document/u/1/d/1L68tmNXCQXucsCV8eS8CBd_F9FZ6TNwKNOaFkA8RfwI/edit).

AudioContext creation and audio rendering errors are reported to web applications via a callback assigned to AudioContext.onerror.

The anchor-scope property allows limiting the visibility of anchor names to a given subtree.

Support of new CSS property `ruby-align` is added. The property accepts one of `space-around` `space-between` `start` and `center` keywords, and controls alignment of ruby base text and ruby annotation text.

Snap Events allow developers reliably listen for when the "snap target" of a scroller changes and perform style adjustments as desired. CSS scroll snap points are often used as a mechanism to create scroll interactive "selection" components, where selection is determined with javascript intersection observers and a scroll end guestimate. By creating built-in events, the invisible state will become actionable, at the right time, and always correct. This feature adds two JavaScript events: scrollsnapchange and scrollsnapchanging. Scrollsnapchange lets developers know, at the completion of a scroll operation (including snapping), that the element to which a scroller is snapped has changed. Scrollsnapchanging gives developers a hint, during a scroll operation, that the user agent intends to snap the scroll container to a new snap target based on the scrolling input so far.

Snap Events allow developers reliably listen for when the "snap target" of a scroller changes and perform style adjustments as desired. CSS scroll snap points are often used as a mechanism to create scroll interactive "selection" components, where selection is determined with javascript intersection observers and a scroll end guestimate. By creating built-in events, the invisible state will become actionable, at the right time, and always correct. This feature adds two JavaScript events: scrollsnapchange and scrollsnapchanging. Scrollsnapchange lets developers know, at the completion of a scroll operation (including snapping), that the element to which a scroller is snapped has changed. Scrollsnapchanging gives developers a hint, during a scroll operation, that the user agent intends to snap the scroll container to a new snap target based on the scrolling input so far.

Dispatches selectionchange event per element when this element(input/textarea) provides a text selection or its selection changes. This is to match the latest specification of selectionchange event. This also matches Safari behavior.

Reconciles the FedCM and Storage Access APIs by making a prior FedCM grant a valid reason to automatically approve a storage access request. When a user grants permission for using their identity with a 3rd party Identity Provider (IdP) on a Relying Party (RP), many IdPs require third-party cookies to function correctly and securely. This proposal aims to satisfy that requirement in a private and secure manner by updating the Storage Access API (SAA) permission checks to not only accept the permission grant that is given by a storage access prompt, but also the permission grant that is given by a FedCM prompt. A key property of this mechanism is limiting the grant to cases explicitly allowed by the RP via the FedCM permissions policy, enforcing a per-frame control for the RP and preventing passive surveillance by the IdP beyond the capabilities that FedCM already grants, as outlined in the Privacy Considerations.

Font-variant-emoji CSS property provides users an easy way to control between colored (emoji-style) and monochromatic (text-style) emoji glyphs presentations. This can be also done by adding an emoji Variation Selector, specifically U+FE0E for text and U+FE0F for emojis, after each emoji codepoint. Using font-variant-emoji CSS property allows web developers to select between emoji style (colored) emoji presentation, text style (monochromatic) emoji presentation and unicode default emoji presentation [0]. This property only affects emojis that are part of a Unicode emoji presentation sequence [1]. [0] https://www.unicode.org/reports/tr51/tr51-25.html#Emoji_Presentation [1] http://www.unicode.org/emoji/charts/emoji-variants.html

Imported ES modules can't currently have their integrity checked, and hence cannot run in environments that require Subresource Integrity or with `require-sri-for` CSP directives. This feature adds an `integrity` section to import maps, enabling developers to map ES module URLs to their integrity metadata, and ensure they only load when they match their expected hashes.

Modifies the Private Aggregation API to add a 'filtering ID' to the aggregatable reports' encrypted payloads. This ID allows histogram contributions with different filtering IDs to be processed separately on the aggregation service. A list of filtering IDs could be provided in an aggregation query and any contributions not matching a listed ID will be filtered out, not contributing to the result. To support the new feature, we update the report version to "1.0" (from "0.1"). By the time this is launched to Stable, all valid aggregation service releases will support the new report version, avoiding backwards compatibility concerns. (Old releases are deprecated on a regular schedule.)

Line-breaks are possible within elements with `display: ruby`. A single pair of a ruby-base and a ruby-text has never been line-breakable, and it has been pushed to the next line if the current line had no enough space for the entire pair. Now each of the ruby-base and the ruby-text can be split into multiple lines.

This feature captures the JS call stack when a web page becomes unresponsive due to JavaScript code running an infinite loop or other very long computation. This helps developers to identify the cause of the unresponsiveness and fix it more easily. The JS call stack is included in the crash reporting API when the reason is unresponsive.

The corresponding implementation on the blink layer based on the w3c api change, which is to add the `ChapterInformation` attribute in the existing `MediaMetadata`. ThisChapterInformation applies to audio as well as video, since MediaSession is for both audio and video. See the propose: https://github.com/w3c/mediasession/issues/273 And the specs change pr: https://github.com/w3c/mediasession/pull/308

Scrollend is a JavaScript event that fires to signal that a scrolling operation has come to an end. Similar to the Element interface[1], the visualViewport interface[2] includes an onscrollend event handler that should be invoked when a scrolling operation on the visualViewport has ended. Chromium already supports adding a scrollend event listener via `visualViewport.addEventListener("scrollend")`. This just makes it possible to also add an event listener using `visualViewport.onscrollend`. [1]https://html.spec.whatwg.org/multipage/webappapis.html#handler-onscrollend [2]https://drafts.csswg.org/cssom-view/#dom-visualviewport-onscrollend.

Chrome 125 removes the window-placement alias for permission and permission policy descriptors. All instances of window-placement are replaced with window-management, which better describes the related API functionality. This is a follow-up to Window Management API feature enhancements and renaming from "Multi-Screen Window Placement API"; for more details, see https://chromestatus.com/feature/5146352391028736