style: Remove a couple trivial dependencies on nsPresContext.

Differential Revision: https://phabricator.services.mozilla.com/D20141

components/style/properties/properties.mako.rs

@@ -3507,7 +3507,7 @@ impl<'a> StyleBuilder<'a> {
         self.modified_reset = true;
         % endif
 
-        <% props_need_device = ["content", "list_style_type", "font_variant_alternates"] %>
+        <% props_need_device = ["font_variant_alternates"] %>
         self.${property.style_struct.ident}.mutate()
             .set_${property.ident}(
                 value,