style: Move moz-control-character-visibility out of mako, and remove support for gecko_pref_controlled_initial_value

No behavior change, just cleanup. Actually seem this technically _adds_ some code even
though it's a cleanup, but that's mostly because of the wrapping of the
derive list.  The resulting code is simpler (more in-line with our usual
things, so I think it's an improvement).

Differential Revision: https://phabricator.services.mozilla.com/D111551

components/style/properties/data.py

@@ -483,6 +483,7 @@ class Longhand(Property):
                 "LineBreak",
                 "MasonryAutoFlow",
                 "MozForceBrokenImageIcon",
+                "text::MozControlCharacterVisibility",
                 "MozListReversed",
                 "MathDepth",
                 "MozScriptMinSize",

components/style/properties/helpers.mako.rs

@@ -707,8 +707,7 @@
 </%def>
 
 <%def name="single_keyword(name, values, vector=False,
-            needs_conversion=False, gecko_pref_controlled_initial_value=None,
-            **kwargs)">
+            needs_conversion=False, **kwargs)">
     <%
         keyword_kwargs = {a: kwargs.pop(a, None) for a in [
             'gecko_constant_prefix',
@@ -725,10 +724,13 @@
         ]}
     %>
 
-    <%def name="inner_body(keyword, needs_conversion=False,
-                           gecko_pref_controlled_initial_value=None)">
-        <%def name="variants(variants)">
-            % for variant in variants:
+    <%def name="inner_body(keyword, needs_conversion=False)">
+        pub use self::computed_value::T as SpecifiedValue;
+        pub mod computed_value {
+            #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
+            #[derive(Clone, Copy, Debug, Eq, FromPrimitive, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+            pub enum T {
+            % for variant in keyword.values_for(engine):
             <%
                 aliases = []
                 for alias, v in keyword.aliases_for(engine).items():
@@ -740,31 +742,14 @@
             % endif
             ${to_camel_case(variant)},
             % endfor
-        </%def>
-        pub use self::computed_value::T as SpecifiedValue;
-        pub mod computed_value {
-            #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-            #[derive(Clone, Copy, Debug, Eq, FromPrimitive, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
-            pub enum T {
-                ${variants(data.longhands_by_name[name].keyword.values_for(engine))}
             }
         }
         #[inline]
         pub fn get_initial_value() -> computed_value::T {
-            % if engine == "gecko" and gecko_pref_controlled_initial_value:
-            if static_prefs::pref!("${gecko_pref_controlled_initial_value.split('=')[0]}") {
-                return computed_value::T::${to_camel_case(gecko_pref_controlled_initial_value.split('=')[1])};
-            }
-            % endif
             computed_value::T::${to_camel_case(values.split()[0])}
         }
         #[inline]
         pub fn get_initial_specified_value() -> SpecifiedValue {
-            % if engine == "gecko" and gecko_pref_controlled_initial_value:
-            if static_prefs::pref!("${gecko_pref_controlled_initial_value.split('=')[0]}") {
-                return SpecifiedValue::${to_camel_case(gecko_pref_controlled_initial_value.split('=')[1])};
-            }
-            % endif
             SpecifiedValue::${to_camel_case(values.split()[0])}
         }
         #[inline]
@@ -790,8 +775,7 @@
     % else:
         <%call expr="longhand(name, keyword=Keyword(name, values, **keyword_kwargs), **kwargs)">
             ${inner_body(Keyword(name, values, **keyword_kwargs),
-                         needs_conversion=needs_conversion,
-                         gecko_pref_controlled_initial_value=gecko_pref_controlled_initial_value)}
+                         needs_conversion=needs_conversion)}
             % if caller:
             ${caller.body()}
             % endif

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

@@ -331,15 +331,13 @@ ${helpers.single_keyword(
     servo_restyle_damage="rebuild_and_reflow",
 )}
 
-${helpers.single_keyword(
+${helpers.predefined_type(
     "-moz-control-character-visibility",
-    "hidden visible",
+    "text::MozControlCharacterVisibility",
+    "Default::default()",
     engines="gecko",
-    gecko_enum_prefix="StyleControlCharacterVisibility",
-    gecko_pref_controlled_initial_value="layout.css.control-characters.visible=visible",
     animation_value_type="none",
-    gecko_ffi_name="mControlCharacterVisibility",
-    spec="Nonstandard",
+    spec="Nonstandard"
 )}
 
 // text underline offset

components/style/values/computed/text.rs

@@ -18,7 +18,7 @@ use crate::Zero;
 use std::fmt::{self, Write};
 use style_traits::{CssWriter, ToCss};
 
-pub use crate::values::specified::text::{TextAlignLast, TextUnderlinePosition};
+pub use crate::values::specified::text::{TextAlignLast, TextUnderlinePosition, MozControlCharacterVisibility};
 pub use crate::values::specified::{LineBreak, OverflowWrap, RubyPosition, WordBreak};
 pub use crate::values::specified::{TextDecorationLine, TextEmphasisPosition};
 pub use crate::values::specified::{TextDecorationSkipInk, TextJustify, TextTransform};

components/style/values/specified/text.rs

@@ -1028,6 +1028,39 @@ pub enum TextJustify {
     InterCharacter,
 }
 
+/// Values for the `-moz-control-character-visibility` CSS property.
+#[repr(u8)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[allow(missing_docs)]
+pub enum MozControlCharacterVisibility {
+    Hidden,
+    Visible,
+}
+
+impl Default for MozControlCharacterVisibility {
+    fn default() -> Self {
+        if static_prefs::pref!("layout.css.control-characters.visible") {
+            Self::Visible
+        } else {
+            Self::Hidden
+        }
+    }
+}
+
+
 /// Values for the `line-break` property.
 #[repr(u8)]
 #[derive(