style: Add CSS support for the hyphenate-character property

Differential Revision: https://phabricator.services.mozilla.com/D133889

components/style/values/specified/mod.rs

@@ -90,6 +90,7 @@ pub use self::text::{InitialLetter, LetterSpacing, LineBreak, LineHeight, TextAl
 pub use self::text::{OverflowWrap, TextEmphasisPosition, TextEmphasisStyle, WordBreak};
 pub use self::text::{TextAlignKeyword, TextDecorationLine, TextOverflow, WordSpacing};
 pub use self::text::{TextDecorationLength, TextDecorationSkipInk, TextJustify, TextTransform};
+pub use self::text::HyphenateCharacter;
 pub use self::time::Time;
 pub use self::transform::{Rotate, Scale, Transform};
 pub use self::transform::{TransformOrigin, TransformStyle, Translate};

components/style/values/specified/text.rs

@@ -37,6 +37,27 @@ pub type WordSpacing = Spacing<LengthPercentage>;
 /// A specified value for the `line-height` property.
 pub type LineHeight = GenericLineHeight<NonNegativeNumber, NonNegativeLengthPercentage>;
 
+/// A value for the `hyphenate-character` property.
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(C, u8)]
+pub enum HyphenateCharacter {
+    /// `auto`
+    Auto,
+    /// `<string>`
+    String(crate::OwnedStr),
+}
+
 impl Parse for InitialLetter {
     fn parse<'i, 't>(
         context: &ParserContext,