)]}'
{"id": 5114591051907072, "name": "Expose CSSStyleValue hierarchy to Worker contexts", "summary": "The CSS Typed OM spec exposes the CSSStyleValue hierarchy to worker global scopes ([Exposed=(Window, Worker, PaintWorklet, LayoutWorklet)]), but Blink only exposed CSSStyleValue, CSSKeywordValue, CSSNumericValue, CSSUnitValue and CSSUnparsedValue to Window and the worklets. As a result these constructors were undefined in Workers, unlike in Firefox and Safari.", "markdown_fields": [], "blink_components": ["Blink>CSS"], "star_count": 16, "search_tags": [], "created": {"by": "jfernandez@chromium.org", "when": "2026-07-15 13:24:57.428279"}, "updated": {"by": "jfernandez@igalia.com", "when": "2026-08-17 09:51:03.136393"}, "category": "Miscellaneous", "category_int": 2, "feature_notes": null, "web_feature": "css-typed-om", "is_official_web_feature": true, "webdx_usecounter_enum": null, "enterprise_feature_categories": [], "enterprise_product_category": 0, "is_releasenotes_content_reviewed": false, "is_releasenotes_publish_ready": false, "stages": [{"id": 5171701768912896, "created": "2026-07-15 13:24:58.067866", "feature_id": 5114591051907072, "stage_type": 220, "display_name": null, "intent_stage": 1, "pm_emails": [], "tl_emails": [], "ux_emails": [], "te_emails": [], "intent_thread_url": null, "announcement_url": null, "experiment_goals": null, "experiment_risks": null, "origin_trial_id": null, "origin_trial_feedback_url": null, "ot_action_requested": false, "ot_approval_buganizer_component": null, "ot_approval_buganizer_custom_field_id": null, "ot_approval_criteria_url": null, "ot_approval_group_email": null, "ot_chromium_trial_name": null, "ot_description": null, "ot_display_name": null, "ot_documentation_url": null, "ot_emails": [], "ot_feedback_submission_url": null, "ot_has_third_party_support": false, "ot_is_critical_trial": false, "ot_is_deprecation_trial": false, "ot_owner_email": null, "ot_requester_email": null, "ot_require_approvals": false, "ot_use_counter_bucket_number": null, "ot_webfeature_use_counter": null, "extensions": [], "experiment_extension_reason": null, "ot_stage_id": null, "finch_url": null, "rollout_milestone": null, "rollout_platforms": [], "rollout_details": null, "rollout_impact": 2, "rollout_stage_plan": null, "enterprise_policies": [], "desktop_first": null, "android_first": null, "ios_first": null, "webview_first": null, "desktop_last": null, "android_last": null, "ios_last": null, "webview_last": null}, {"id": 6297601675755520, "created": "2026-07-15 13:24:58.069559", "feature_id": 5114591051907072, "stage_type": 230, "display_name": null, "intent_stage": 2, "pm_emails": [], "tl_emails": [], "ux_emails": [], "te_emails": [], "intent_thread_url": null, "announcement_url": null, "experiment_goals": null, "experiment_risks": null, "origin_trial_id": null, "origin_trial_feedback_url": null, "ot_action_requested": false, "ot_approval_buganizer_component": null, "ot_approval_buganizer_custom_field_id": null, "ot_approval_criteria_url": null, "ot_approval_group_email": null, "ot_chromium_trial_name": null, "ot_description": null, "ot_display_name": null, "ot_documentation_url": null, "ot_emails": [], "ot_feedback_submission_url": null, "ot_has_third_party_support": false, "ot_is_critical_trial": false, "ot_is_deprecation_trial": false, "ot_owner_email": null, "ot_requester_email": null, "ot_require_approvals": false, "ot_use_counter_bucket_number": null, "ot_webfeature_use_counter": null, "extensions": [], "experiment_extension_reason": null, "ot_stage_id": null, "finch_url": null, "rollout_milestone": null, "rollout_platforms": [], "rollout_details": null, "rollout_impact": 2, "rollout_stage_plan": null, "enterprise_policies": [], "desktop_first": null, "android_first": null, "ios_first": null, "webview_first": null, "desktop_last": null, "android_last": null, "ios_last": null, "webview_last": null}, {"id": 4890226792202240, "created": "2026-07-15 13:24:58.070753", "feature_id": 5114591051907072, "stage_type": 250, "display_name": null, "intent_stage": 3, "pm_emails": [], "tl_emails": [], "ux_emails": [], "te_emails": [], "intent_thread_url": null, "announcement_url": null, "experiment_goals": null, "experiment_risks": null, "origin_trial_id": null, "origin_trial_feedback_url": null, "ot_action_requested": false, "ot_approval_buganizer_component": null, "ot_approval_buganizer_custom_field_id": null, "ot_approval_criteria_url": null, "ot_approval_group_email": null, "ot_chromium_trial_name": null, "ot_description": null, "ot_display_name": null, "ot_documentation_url": null, "ot_emails": [], "ot_feedback_submission_url": null, "ot_has_third_party_support": false, "ot_is_critical_trial": false, "ot_is_deprecation_trial": false, "ot_owner_email": null, "ot_requester_email": null, "ot_require_approvals": false, "ot_use_counter_bucket_number": null, "ot_webfeature_use_counter": null, "extensions": [], "experiment_extension_reason": null, "ot_stage_id": null, "finch_url": null, "rollout_milestone": null, "rollout_platforms": [], "rollout_details": null, "rollout_impact": 2, "rollout_stage_plan": null, "enterprise_policies": [], "desktop_first": null, "android_first": null, "ios_first": null, "webview_first": null, "desktop_last": null, "android_last": null, "ios_last": null, "webview_last": null}, {"id": 6016126699044864, "created": "2026-07-15 13:24:58.073101", "feature_id": 5114591051907072, "stage_type": 260, "display_name": null, "intent_stage": 5, "pm_emails": [], "tl_emails": [], "ux_emails": [], "te_emails": [], "intent_thread_url": "https://groups.google.com/a/chromium.org/d/msgid/blink-dev/0786569a-3c4b-421c-af22-a6bc4a717ccc%40igalia.com", "announcement_url": null, "experiment_goals": null, "experiment_risks": null, "origin_trial_id": null, "origin_trial_feedback_url": null, "ot_action_requested": false, "ot_approval_buganizer_component": null, "ot_approval_buganizer_custom_field_id": null, "ot_approval_criteria_url": null, "ot_approval_group_email": null, "ot_chromium_trial_name": null, "ot_description": null, "ot_display_name": null, "ot_documentation_url": null, "ot_emails": [], "ot_feedback_submission_url": null, "ot_has_third_party_support": false, "ot_is_critical_trial": false, "ot_is_deprecation_trial": false, "ot_owner_email": null, "ot_requester_email": null, "ot_require_approvals": false, "ot_use_counter_bucket_number": null, "ot_webfeature_use_counter": null, "extensions": [], "experiment_extension_reason": null, "ot_stage_id": null, "finch_url": null, "rollout_milestone": null, "rollout_platforms": [], "rollout_details": null, "rollout_impact": 2, "rollout_stage_plan": null, "enterprise_policies": [], "desktop_first": 154, "android_first": 154, "ios_first": null, "webview_first": 154, "desktop_last": null, "android_last": null, "ios_last": null, "webview_last": null}], "accurate_as_of": "2026-08-17 09:51:03.136393", "creator_email": "jfernandez@chromium.org", "updater_email": "jfernandez@igalia.com", "owner_emails": ["jfernandez@igalia.com"], "editor_emails": [], "cc_emails": [], "spec_mentor_emails": [], "unlisted": false, "deleted": false, "editors": [], "cc_recipients": [], "spec_mentors": [], "creator": "jfernandez@chromium.org", "feature_type": "Chromium catches up", "feature_type_int": 1, "intent_stage": "None", "intent_stage_int": 0, "active_stage_id": 6016126699044864, "bug_url": "https://issues.chromium.org/issues/534781956", "launch_bug_url": null, "new_crbug_url": "https://bugs.chromium.org/p/chromium/issues/entry?components=Blink>CSS&blocking=534781956&cc=jfernandez@igalia.com", "screenshot_links": [], "first_enterprise_notification_milestone": null, "enterprise_impact": 1, "breaking_change": false, "confidential": false, "shipping_year": 2026, "flag_name": null, "finch_name": null, "non_finch_justification": "This is just a minor CSS change to allow some CSS javascript bindings to be run in Worker context, but that were already exposed to the Web via Window context.", "ongoing_constraints": null, "rollout_plan": 0, "rollout_plan_displayname": "Will ship enabled for all users", "motivation": "Aligns Chrome with the spec's [Exposed] set and removes a cross\u2011thread inconsistency (these constructors are currently undefined in workers); enables off\u2011main\u2011thread CSS value manipulation", "devtrial_instructions": null, "activation_risks": null, "measurement": null, "availability_expectation": null, "adoption_expectation": null, "adoption_plan": null, "initial_public_proposal_url": null, "explainer_links": [], "requires_embedder_support": false, "spec_link": "https://www.w3.org/TR/css-typed-om-1/#stylevalue-subclasses", "api_spec": true, "automation_spec": false, "interop_compat_risks": "This feature is already shipped by Firefox and Safari and it's purely additive worker\u2011scope exposure; zero change to existing Window behavior; matches the spec. Only theoretical risk: content that feature\u2011detects these globals inside a worker\n\n", "all_platforms": true, "all_platforms_descr": null, "non_oss_deps": null, "anticipated_spec_changes": "https://github.com/w3c/csswg-drafts/issues/14229", "security_risks": null, "ergonomics_risks": null, "wpt": true, "wpt_descr": "css/css-typed-om/stylevalue-subclasses/*.any.js (global=window,worker): cssKeywordValue, cssKeywordValue-value, cssUnparsedValue-empty, numeric-objects/cssUnitValue-to; and (full\u2011scope) the converted create-a-type, cssMathInvert-type, cssMathNegate-type, add-two-types, cssnumericvalue-multiply-two-types, arithmetic, to .any.js. (The CSSMath* ones require the full\u2011scope exposure.)\n\nhttps://wpt.fyi/results/css/css-typed-om/stylevalue-subclasses?label=experimental&label=master&aligned\n\n", "webview_risks": null, "devrel_emails": ["devrel-chromestatus-all@google.com"], "debuggability": "No special tooling; interfaces work in the worker DevTools console like any other worker\u2011exposed API", "doc_links": [], "sample_links": [], "prefixed": null, "tags": [], "tag_review": null, "tag_review_status": "Not applicable", "tag_review_status_int": 4, "security_review_status": "Pending", "security_review_status_int": 1, "privacy_review_status": "Pending", "privacy_review_status_int": 1, "security_continuity_id": null, "security_launch_issue_id": null, "updated_display": null, "resources": {"samples": [], "docs": []}, "comments": null, "ff_views": 1, "safari_views": 1, "web_dev_views": 4, "browsers": {"chrome": {"bug": "https://issues.chromium.org/issues/534781956", "blink_components": ["Blink>CSS"], "devrel": ["devrel-chromestatus-all@google.com"], "owners": ["jfernandez@igalia.com"], "origintrial": false, "prefixed": null, "flag": false, "status": {"text": "Proposed", "val": 2, "milestone_str": "Proposed"}, "announced": true, "desktop": 154, "android": 154, "webview": 154, "ios": null}, "ff": {"view": {"url": null, "notes": null, "text": "Shipped/Shipping", "val": 1}}, "safari": {"view": {"url": null, "notes": null, "text": "Shipped/Shipping", "val": 1}}, "webdev": {"view": {"text": "No signals", "val": 4, "url": null, "notes": null}}, "other": {"view": {"text": null, "val": null, "url": null, "notes": null}}}, "standards": {"spec": "https://www.w3.org/TR/css-typed-om-1/#stylevalue-subclasses", "maturity": {"text": "Final published standard: Recommendation, Living Standard, Candidate Recommendation, or similar final form", "short_text": "Published standard", "val": 5}}, "is_released": false, "is_enterprise_feature": false, "experiment_timeline": null, "ai_test_eval_report": null, "ai_test_eval_run_status": null, "ai_test_eval_status_timestamp": null}