style: Avoid unused context argument.

In custom_properties::SpecifiedValue::parse.

It's not a big deal now, but it's useful to simplify testing this stuff, since
it avoids forcing us to mock it.

components/style/custom_properties.rs

@@ -8,7 +8,6 @@
 
 use Atom;
 use cssparser::{Delimiter, Parser, ParserInput, SourcePosition, Token, TokenSerializationType};
-use parser::ParserContext;
 use precomputed_hash::PrecomputedHash;
 use properties::{CSSWideKeyword, DeclaredValue};
 use selector_map::{PrecomputedHashSet, PrecomputedDiagnosticHashMap};
@@ -246,15 +245,17 @@ impl ComputedValue {
 impl SpecifiedValue {
     /// Parse a custom property SpecifiedValue.
     pub fn parse<'i, 't>(
-        _context: &ParserContext,
         input: &mut Parser<'i, 't>,
     ) -> Result<Box<Self>, ParseError<'i>> {
         let mut references = PrecomputedHashSet::default();
-        let (first, css, last) = parse_self_contained_declaration_value(input, Some(&mut references))?;
+
+        let (first_token_type, css, last_token_type) =
+            parse_self_contained_declaration_value(input, Some(&mut references))?;
+
         Ok(Box::new(SpecifiedValue {
             css: css.into_owned(),
-            first_token_type: first,
+            first_token_type,
-            last_token_type: last,
+            last_token_type,
             references
         }))
     }

components/style/properties/properties.mako.rs

@@ -1635,7 +1635,7 @@ impl PropertyDeclaration {
                 // This probably affects some test results.
                 let value = match input.try(|i| CSSWideKeyword::parse(i)) {
                     Ok(keyword) => DeclaredValueOwned::CSSWideKeyword(keyword),
-                    Err(()) => match ::custom_properties::SpecifiedValue::parse(context, input) {
+                    Err(()) => match ::custom_properties::SpecifiedValue::parse(input) {
                         Ok(value) => DeclaredValueOwned::Value(value),
                         Err(e) => return Err(PropertyDeclarationParseError::InvalidValue(name.to_string().into(),
                         ValueParseError::from_parse_error(e))),

components/style/values/specified/image.rs

@@ -908,18 +908,18 @@ impl Parse for ColorStop {
 }
 
 impl Parse for PaintWorklet {
-    fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
+    fn parse<'i, 't>(
+        _context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<Self, ParseError<'i>> {
         input.expect_function_matching("paint")?;
         input.parse_nested_block(|input| {
             let name = Atom::from(&**input.expect_ident()?);
             let arguments = input.try(|input| {
                 input.expect_comma()?;
-                input.parse_comma_separated(|input| Ok(*SpecifiedValue::parse(context, input)?))
+                input.parse_comma_separated(|input| Ok(*SpecifiedValue::parse(input)?))
             }).unwrap_or(vec![]);
-            Ok(PaintWorklet {
+            Ok(PaintWorklet { name, arguments })
-                name: name,
-                arguments: arguments,
-            })
         })
     }
 }