style: Distinguish between specified and computed URLs.

This is needed to serialize computed URLs correctly from getComputedStyle.

Bug: 1461288
Reviewed-by: xidorn
MozReview-Commit-ID: 9wakhqNrszb

components/style/values/generics/counters.rs

@@ -4,8 +4,14 @@
 
 //! Generic types for counters-related CSS values.
 
+#[cfg(feature = "servo")]
+use computed_values::list_style_type::T as ListStyleType;
 use std::ops::Deref;
 use values::CustomIdent;
+#[cfg(feature = "gecko")]
+use values::generics::CounterStyleOrNone;
+#[cfg(feature = "gecko")]
+use values::specified::Attr;
 
 /// A name / value pair for counters.
 #[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
@@ -74,3 +80,78 @@ impl<I> Default for Counters<I> {
         Counters(vec![].into_boxed_slice())
     }
 }
+
+#[cfg(feature = "servo")]
+type CounterStyleType = ListStyleType;
+
+#[cfg(feature = "gecko")]
+type CounterStyleType = CounterStyleOrNone;
+
+#[cfg(feature = "servo")]
+#[inline]
+fn is_decimal(counter_type: &CounterStyleType) -> bool {
+    *counter_type == ListStyleType::Decimal
+}
+
+#[cfg(feature = "gecko")]
+#[inline]
+fn is_decimal(counter_type: &CounterStyleType) -> bool {
+    *counter_type == CounterStyleOrNone::decimal()
+}
+
+/// The specified value for the `content` property.
+///
+/// https://drafts.csswg.org/css-content/#propdef-content
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
+pub enum Content<ImageUrl> {
+    /// `normal` reserved keyword.
+    Normal,
+    /// `none` reserved keyword.
+    None,
+    /// `-moz-alt-content`.
+    #[cfg(feature = "gecko")]
+    MozAltContent,
+    /// Content items.
+    Items(#[css(iterable)] Box<[ContentItem<ImageUrl>]>),
+}
+
+impl<ImageUrl> Content<ImageUrl> {
+    /// Set `content` property to `normal`.
+    #[inline]
+    pub fn normal() -> Self {
+        Content::Normal
+    }
+
+}
+
+/// Items for the `content` property.
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
+pub enum ContentItem<ImageUrl> {
+    /// Literal string content.
+    String(Box<str>),
+    /// `counter(name, style)`.
+    #[css(comma, function)]
+    Counter(CustomIdent, #[css(skip_if = "is_decimal")] CounterStyleType),
+    /// `counters(name, separator, style)`.
+    #[css(comma, function)]
+    Counters(
+        CustomIdent,
+        Box<str>,
+        #[css(skip_if = "is_decimal")] CounterStyleType,
+    ),
+    /// `open-quote`.
+    OpenQuote,
+    /// `close-quote`.
+    CloseQuote,
+    /// `no-open-quote`.
+    NoOpenQuote,
+    /// `no-close-quote`.
+    NoCloseQuote,
+    /// `attr([namespace? `|`]? ident)`
+    #[cfg(feature = "gecko")]
+    Attr(Attr),
+    /// `url(url)`
+    Url(ImageUrl),
+}