Add :has-slotted feature (#2328)

Co-authored-by: Daniel D. Beck <[email protected]>

Author: jamesnw

features/has-slotted.yml

@@ -0,0 +1,8 @@
+name: :has-slotted
+description: The `:has-slotted` CSS pseudo-class matches `<slot>` elements where the fallback content is not shown. The pseudo-class matches any slotted content, including white space, text nodes, or elements.
+spec: https://drafts.csswg.org/css-scoping-1/#the-has-slotted-pseudo
+group:
+  - selectors
+  - web-components
+compat_features:
+  - css.selectors.has-slotted

features/has-slotted.yml.dist

@@ -0,0 +1,8 @@
+# Generated from: has-slotted.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: false
+  support: {}
+compat_features:
+  - css.selectors.has-slotted

features/slot.yml

@@ -6,3 +6,16 @@ group:
   - web-components
 status:
   compute_from: html.elements.slot
+compat_features:
+  - api.Element.assignedSlot
+  - api.Element.slot
+  - api.HTMLSlotElement
+  - api.HTMLSlotElement.assignedElements
+  - api.HTMLSlotElement.assignedNodes
+  - api.HTMLSlotElement.name
+  - api.HTMLSlotElement.slotchange_event
+  - api.Text.assignedSlot
+  - css.selectors.slotted
+  - html.elements.slot
+  - html.elements.slot.name
+  - html.global_attributes.slot

features/slot.yml.dist

@@ -86,7 +86,3 @@ compat_features:
   #   safari: "10"
   #   safari_ios: "10"
   - html.global_attributes.slot
-
-  # baseline: false
-  # support: {}
-  - css.selectors.has-slotted