Auto merge of #15287 - hiikezoe:css-animation, r=heycam

Counter part of bug 1328787 - Stylo: Convert Servo's animation keyframes and store them into Gecko's keyframes

<!-- Please describe your changes on the following line: -->
Reviewed by @heycam, An exception is auto-generated bindgen stuff, I did not include it in patches on bugzilla.  The bindgen diff included in this PR was generated with  b5c94bad37.  It might be bit-rotted.

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [X] These changes do not require tests because gecko has test cases.

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components/style/properties/properties.mako.rs

@@ -737,16 +737,6 @@ enum StaticId {
     Shorthand(ShorthandId),
 }
 include!(concat!(env!("OUT_DIR"), "/static_ids.rs"));
-<%
-    def alias_to_nscsspropertyid(alias):
-        if alias == "word-wrap":
-            return "nsCSSPropertyID_eCSSPropertyAlias_WordWrap"
-        return "nsCSSPropertyID::eCSSPropertyAlias_%s" % to_camel_case(alias)
-    def to_nscsspropertyid(ident):
-        if ident == "float":
-            ident = "float_"
-        return "nsCSSPropertyID::eCSSProperty_%s" % ident
-%>
 impl PropertyId {
     /// Returns a given property from the string `s`.
     ///
@@ -771,21 +761,21 @@ impl PropertyId {
         use gecko_bindings::structs::*;
         match id {
             % for property in data.longhands:
-                ${to_nscsspropertyid(property.ident)} => {
+                ${helpers.to_nscsspropertyid(property.ident)} => {
                     Ok(PropertyId::Longhand(LonghandId::${property.camel_case}))
                 }
                 % for alias in property.alias:
-                    ${alias_to_nscsspropertyid(alias)} => {
+                    ${helpers.alias_to_nscsspropertyid(alias)} => {
                         Ok(PropertyId::Longhand(LonghandId::${property.camel_case}))
                     }
                 % endfor
             % endfor
             % for property in data.shorthands:
-                ${to_nscsspropertyid(property.ident)} => {
+                ${helpers.to_nscsspropertyid(property.ident)} => {
                     Ok(PropertyId::Shorthand(ShorthandId::${property.camel_case}))
                 }
                 % for alias in property.alias:
-                    ${alias_to_nscsspropertyid(alias)} => {
+                    ${helpers.alias_to_nscsspropertyid(alias)} => {
                         Ok(PropertyId::Shorthand(ShorthandId::${property.camel_case}))
                     }
                 % endfor
@@ -804,14 +794,14 @@ impl PropertyId {
             PropertyId::Longhand(id) => match id {
                 % for property in data.longhands:
                     LonghandId::${property.camel_case} => {
-                        Ok(${to_nscsspropertyid(property.ident)})
+                        Ok(${helpers.to_nscsspropertyid(property.ident)})
                     }
                 % endfor
             },
             PropertyId::Shorthand(id) => match id {
                 % for property in data.shorthands:
                     ShorthandId::${property.camel_case} => {
-                        Ok(${to_nscsspropertyid(property.ident)})
+                        Ok(${helpers.to_nscsspropertyid(property.ident)})
                     }
                 % endfor
             },
@@ -921,7 +911,7 @@ impl ToCss for PropertyDeclaration {
                 pref_ident = "float_"
         %>
         if structs::root::mozilla::SERVO_PREF_ENABLED_${pref_ident} {
-            let id = structs::${to_nscsspropertyid(property.ident)};
+            let id = structs::${helpers.to_nscsspropertyid(property.ident)};
             let enabled = unsafe { bindings::Gecko_PropertyId_IsPrefEnabled(id) };
             if !enabled {
                 return PropertyDeclarationParseResult::ExperimentalProperty