Box custom property

components/style/custom_properties.rs

@@ -8,7 +8,7 @@
 
 use Atom;
 use cssparser::{Delimiter, Parser, SourcePosition, Token, TokenSerializationType};
-use parser::{Parse, ParserContext};
+use parser::ParserContext;
 use properties::DeclaredValue;
 use std::ascii::AsciiExt;
 use std::borrow::Cow;
@@ -129,16 +129,17 @@ impl ComputedValue {
     }
 }
 
-impl Parse for SpecifiedValue {
+impl SpecifiedValue {
-    fn parse(_context: &ParserContext, input: &mut Parser) -> Result<Self, ()> {
+    /// Parse a custom property SpecifiedValue.
+    pub fn parse(_context: &ParserContext, input: &mut Parser) -> Result<Box<Self>, ()> {
         let mut references = Some(HashSet::new());
         let (first, css, last) = try!(parse_self_contained_declaration_value(input, &mut references));
-        Ok(SpecifiedValue {
+        Ok(Box::new(SpecifiedValue {
             css: css.into_owned(),
             first_token_type: first,
             last_token_type: last,
             references: references.unwrap(),
-        })
+        }))
     }
 }
 
@@ -328,7 +329,7 @@ pub fn cascade<'a>(custom_properties: &mut Option<HashMap<&'a Name, BorrowedSpec
                    inherited: &'a Option<Arc<HashMap<Name, ComputedValue>>>,
                    seen: &mut HashSet<&'a Name>,
                    name: &'a Name,
-                   specified_value: &'a DeclaredValue<SpecifiedValue>) {
+                   specified_value: &'a DeclaredValue<Box<SpecifiedValue>>) {
     let was_already_present = !seen.insert(name);
     if was_already_present {
         return;

components/style/properties/properties.mako.rs

@@ -850,7 +850,7 @@ pub enum PropertyDeclaration {
     % endfor
     /// A custom property declaration, with the property name and the declared
     /// value.
-    Custom(::custom_properties::Name, DeclaredValue<::custom_properties::SpecifiedValue>),
+    Custom(::custom_properties::Name, DeclaredValue<Box<::custom_properties::SpecifiedValue>>),
 }
 
 impl HasViewportPercentage for PropertyDeclaration {
@@ -1029,7 +1029,8 @@ impl PropertyDeclaration {
                         Err(()) => return PropertyDeclarationParseResult::InvalidValue,
                     }
                 };
-                result_list.push((PropertyDeclaration::Custom(name, value), Importance::Normal));
+                result_list.push((PropertyDeclaration::Custom(name, value),
+                                  Importance::Normal));
                 return PropertyDeclarationParseResult::ValidOrIgnoredDeclaration;
             }
             PropertyId::Longhand(id) => match id {

tests/unit/style/size_of.rs

@@ -7,7 +7,7 @@ use style::properties::{PropertyDeclaration, specified_value_sizes};
 
 #[test]
 fn size_of_property_declaration() {
-    let old = 96;
+    let old = 72;
     let new = size_of::<PropertyDeclaration>();
     if new < old {
         panic!("Your changes have decreased the stack size of PropertyDeclaration enum from {} to {}. \