style: Fix elements not being query containers for the pseudo-element they originate. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D164807

components/style/gecko/selector_parser.rs

@@ -8,6 +8,7 @@ use crate::computed_value_flags::ComputedValueFlags;
 use crate::gecko_bindings::structs::RawServoSelectorList;
 use crate::gecko_bindings::sugar::ownership::{HasBoxFFI, HasFFI, HasSimpleFFI};
 use crate::invalidation::element::document_state::InvalidationMatchingData;
+use crate::properties::ComputedValues;
 use crate::selector_parser::{Direction, HorizontalDirection, SelectorParser};
 use crate::str::starts_with_ignore_ascii_case;
 use crate::string_cache::{Atom, Namespace, WeakAtom, WeakNamespace};
@@ -17,6 +18,7 @@ use cssparser::{CowRcStr, SourceLocation, ToCss, Token};
 use dom::{DocumentState, ElementState};
 use selectors::parser::SelectorParseErrorKind;
 use selectors::SelectorList;
+use servo_arc::Arc;
 use std::fmt;
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss as ToCss_};
 
@@ -233,7 +235,7 @@ pub struct SelectorImpl;
 
 /// A set of extra data to carry along with the matching context, either for
 /// selector-matching or invalidation.
-#[derive(Debug, Default)]
+#[derive(Default)]
 pub struct ExtraMatchingData {
     /// The invalidation data to invalidate doc-state pseudo-classes correctly.
     pub invalidation_data: InvalidationMatchingData,
@@ -241,6 +243,10 @@ pub struct ExtraMatchingData {
     /// The invalidation bits from matching container queries. These are here
     /// just for convenience mostly.
     pub cascade_input_flags: ComputedValueFlags,
+
+    /// The style of the originating element in order to evaluate @container
+    /// size queries affecting pseudo-elements.
+    pub originating_element_style: Option<Arc<ComputedValues>>,
 }
 
 impl ::selectors::SelectorImpl for SelectorImpl {