Make display: flex experimental.

components/style/properties.mako.rs

@@ -407,15 +407,66 @@ pub mod longhands {
     ${new_style_struct("Box", is_inherited=False)}
 
     // TODO(SimonSapin): don't parse `inline-table`, since we don't support it
-    <%self:single_keyword_computed name="display"
+    <%self:longhand name="display" custom_cascade="True">
-            custom_cascade="True"
+        <%
-            values="inline block inline-block
+            values = """inline block inline-block
-            table inline-table table-row-group table-header-group table-footer-group
+                table inline-table table-row-group table-header-group table-footer-group
-            table-row table-column-group table-column table-cell table-caption
+                table-row table-column-group table-column table-cell table-caption
-            list-item flex
+                list-item flex
-            none">
+                none
+            """.split()
+            experimental_values = set("flex".split())
+        %>
+        pub use self::computed_value::T as SpecifiedValue;
         use values::computed::Context;
 
+        pub mod computed_value {
+            #[allow(non_camel_case_types)]
+            #[derive(Clone, Eq, PartialEq, Copy, Hash, RustcEncodable, Debug, HeapSizeOf)]
+            #[derive(Deserialize, Serialize)]
+            pub enum T {
+                % for value in values:
+                    ${to_rust_ident(value)},
+                % endfor
+            }
+
+            impl ::cssparser::ToCss for T {
+                fn to_css<W>(&self, dest: &mut W) -> ::std::fmt::Result
+                where W: ::std::fmt::Write {
+                    match self {
+                        % for value in values:
+                            &T::${to_rust_ident(value)} => dest.write_str("${value}"),
+                        % endfor
+                    }
+                }
+            }
+        }
+        #[inline] pub fn get_initial_value() -> computed_value::T {
+            computed_value::T::${to_rust_ident(values[0])}
+        }
+        pub fn parse(_context: &ParserContext, input: &mut Parser)
+                     -> Result<SpecifiedValue, ()> {
+            match_ignore_ascii_case! { try!(input.expect_ident()),
+                % for value in values[:-1]:
+                    "${value}" => {
+                        % if value in experimental_values:
+                            if !::util::opts::experimental_enabled() { return Err(()) }
+                        % endif
+                        Ok(computed_value::T::${to_rust_ident(value)})
+                    },
+                % endfor
+                % for value in values[-1:]:
+                    "${value}" => {
+                        % if value in experimental_values:
+                            if !::util::opts::experimental_enabled() { return Err(()) }
+                        % endif
+                        Ok(computed_value::T::${to_rust_ident(value)})
+                    }
+                % endfor
+                _ => Err(())
+            }
+        }
+
         impl ToComputedValue for SpecifiedValue {
             type ComputedValue = computed_value::T;
 
@@ -457,7 +508,7 @@ pub mod longhands {
                 longhands::_servo_text_decorations_in_effect::derive_from_display(*computed_value,
                                                                                   &context);
         }
-    </%self:single_keyword_computed>
+    </%self:longhand>
 
     ${single_keyword("position", "static absolute relative fixed")}
     ${single_keyword("float", "none left right")}