style: Simplify some conversion code used for mapped attributes.

These days for the types we share computed value representation we don't really
need any special code.

Differential Revision: https://phabricator.services.mozilla.com/D17763

components/style/properties/longhands/border.mako.rs

@@ -61,15 +61,6 @@
     )}
 % endfor
 
-${helpers.gecko_keyword_conversion(
-    Keyword('border-style',
-    "none solid double dotted dashed hidden groove ridge inset outset",
-    gecko_enum_prefix="StyleBorderStyle",
-    gecko_inexhaustive=True),
-    type="crate::values::specified::BorderStyle",
-)}
-
-// FIXME(#4126): when gfx supports painting it, make this Size2D<LengthPercentage>
 % for corner in ALL_CORNERS:
     <%
         corner_name = corner[0]

components/style/values/computed/box.rs

@@ -38,7 +38,7 @@ pub type Perspective = GenericPerspective<NonNegativeLength>;
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss,
+    Clone, Copy, Debug, Eq, FromPrimitive, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss,
 )]
 #[repr(u8)]
 /// A computed value for the `float` property.
@@ -97,7 +97,7 @@ impl ToComputedValue for SpecifiedFloat {
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss,
+    Clone, Copy, Debug, Eq, FromPrimitive, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss,
 )]
 /// A computed value for the `clear` property.
 pub enum Clear {

components/style/values/specified/border.rs

@@ -30,6 +30,7 @@ use style_traits::{CssWriter, ParseError, ToCss};
     Copy,
     Debug,
     Eq,
+    FromPrimitive,
     MallocSizeOf,
     Ord,
     Parse,