style: Implement the border-{block,inline}-{color,style,width} shorth…

…ands.

Bug: 1520236
Reviewed-by: emilio

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

@@ -356,6 +356,50 @@ pub fn parse_border<'i, 't>(
     }
 </%helpers:shorthand>
 
+% for axis in ["block", "inline"]:
+    % for prop in ["width", "style", "color"]:
+        <%
+            spec = "https://drafts.csswg.org/css-logical/#propdef-border-%s-%s" % (axis, prop)
+        %>
+        <%helpers:shorthand
+            name="border-${axis}-${prop}"
+            sub_properties="${' '.join(
+                'border-%s-%s-%s' % (axis, side, prop)
+                for side in ['start', 'end']
+            )}"
+            spec="${spec}">
+
+            use crate::properties::longhands::border_${axis}_start_${prop};
+            pub fn parse_value<'i, 't>(
+                context: &ParserContext,
+                input: &mut Parser<'i, 't>,
+            ) -> Result<Longhands, ParseError<'i>> {
+                let start_value = border_${axis}_start_${prop}::parse(context, input)?;
+                let end_value =
+                    input.try(|input| border_${axis}_start_${prop}::parse(context, input)).unwrap_or_else(|_| start_value.clone());
+
+                Ok(expanded! {
+                    border_${axis}_start_${prop}: start_value,
+                    border_${axis}_end_${prop}: end_value,
+                })
+            }
+
+            impl<'a> ToCss for LonghandsToSerialize<'a>  {
+                fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result where W: fmt::Write {
+                    self.border_${axis}_start_${prop}.to_css(dest)?;
+
+                    if self.border_${axis}_end_${prop} != self.border_${axis}_start_${prop} {
+                        dest.write_str(" ")?;
+                        self.border_${axis}_end_${prop}.to_css(dest)?;
+                    }
+
+                    Ok(())
+                }
+            }
+        </%helpers:shorthand>
+    % endfor
+% endfor
+
 % for axis in ["block", "inline"]:
     <%
         spec = "https://drafts.csswg.org/css-logical/#propdef-border-%s" % (axis)