Auto merge of #14358 - chenpighead:webkit-text-stroke, r=canaltinova

stylo - implement -webkit-text-fill-color and -webkit-text-stroke.

<!-- Please describe your changes on the following line: -->

Implement -webkit-text-fill-color property.
Implement -webkit-text-stroke property, along with -webkit-text-stroke-width and -webkit-text-stroke-color longhand properties.

---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #13849 (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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components/style/properties/gecko.mako.rs

@@ -1819,7 +1819,8 @@ fn static_assert() {
 
 
 <%self:impl_trait style_struct_name="InheritedText"
-                  skip_longhands="text-align text-emphasis-style text-shadow line-height letter-spacing word-spacing">
+                  skip_longhands="text-align text-emphasis-style text-shadow line-height letter-spacing word-spacing
+                                  -webkit-text-stroke-width">
 
     <% text_align_keyword = Keyword("text-align", "start end left right center justify -moz-center -moz-left " +
                                                   "-moz-right match-parent") %>
@@ -1966,6 +1967,13 @@ fn static_assert() {
         self.gecko.mTextEmphasisStyle = other.gecko.mTextEmphasisStyle;
     }
 
+    #[allow(non_snake_case)]
+    pub fn set__webkit_text_stroke_width(&mut self, v: longhands::_webkit_text_stroke_width::computed_value::T) {
+        self.gecko.mWebkitTextStrokeWidth.set_value(CoordDataValue::Coord(v.0));
+    }
+
+    <%call expr="impl_coord_copy('_webkit_text_stroke_width', 'mWebkitTextStrokeWidth')"></%call>
+
 </%self:impl_trait>
 
 <%self:impl_trait style_struct_name="Text"