--- a/servo/components/style/properties/gecko.mako.rs
+++ b/servo/components/style/properties/gecko.mako.rs
@@ -2855,16 +2855,35 @@ fn static_assert() {
         use gecko_bindings::bindings::Gecko_CopyWillChangeFrom;
 
         self.gecko.mWillChangeBitField = other.gecko.mWillChangeBitField;
         unsafe {
             Gecko_CopyWillChangeFrom(&mut self.gecko, &other.gecko as *const _ as *mut _);
         }
     }
 
+    pub fn clone_will_change(&self) -> longhands::will_change::computed_value::T {
+        use properties::longhands::will_change::computed_value::T;
+        use gecko_bindings::structs::nsIAtom;
+        use gecko_string_cache::Atom;
+        use values::CustomIdent;
+
+        if self.gecko.mWillChange.mBuffer.len() == 0 {
+            T::Auto
+        } else {
+            T::AnimateableFeatures(
+                self.gecko.mWillChange.mBuffer.iter().map(|gecko_atom| {
+                    CustomIdent(
+                        unsafe { Atom::from_addrefed(*gecko_atom as *mut nsIAtom) }
+                    )
+                }).collect()
+            )
+        }
+    }
+
     <% impl_shape_source("shape_outside", "mShapeOutside") %>
 
     pub fn set_contain(&mut self, v: longhands::contain::computed_value::T) {
         use gecko_bindings::structs::NS_STYLE_CONTAIN_NONE;
         use gecko_bindings::structs::NS_STYLE_CONTAIN_STRICT;
         use gecko_bindings::structs::NS_STYLE_CONTAIN_LAYOUT;
         use gecko_bindings::structs::NS_STYLE_CONTAIN_STYLE;
         use gecko_bindings::structs::NS_STYLE_CONTAIN_PAINT;
@@ -3071,16 +3090,40 @@ fn static_assert() {
         let repeat_x = to_ns(servo.0);
         let repeat_y = to_ns(servo.1);
         nsStyleImageLayers_Repeat {
               mXRepeat: repeat_x,
               mYRepeat: repeat_y,
         }
     </%self:simple_image_array_property>
 
+    pub fn clone_${shorthand}_repeat(&self) -> longhands::${shorthand}_repeat::computed_value::T {
+        use properties::longhands::${shorthand}_repeat::single_value::computed_value::T;
+        use properties::longhands::${shorthand}_repeat::single_value::computed_value::RepeatKeyword;
+        use gecko_bindings::structs::StyleImageLayerRepeat;
+
+        fn to_servo(repeat: StyleImageLayerRepeat) -> RepeatKeyword {
+            match repeat {
+                StyleImageLayerRepeat::Repeat => RepeatKeyword::Repeat,
+                StyleImageLayerRepeat::Space => RepeatKeyword::Space,
+                StyleImageLayerRepeat::Round => RepeatKeyword::Round,
+                StyleImageLayerRepeat::NoRepeat => RepeatKeyword::NoRepeat,
+                x => panic!("Found unexpected value in style struct for ${shorthand}_repeat property: {:?}", x),
+            }
+        }
+
+        longhands::${shorthand}_repeat::computed_value::T (
+            self.gecko.${image_layers_field}.mLayers.iter()
+                .take(self.gecko.${image_layers_field}.mRepeatCount as usize)
+                .map(|ref layer| {
+                    T(to_servo(layer.mRepeat.mXRepeat), to_servo(layer.mRepeat.mYRepeat))
+                }).collect()
+        )
+    }
+
     <% impl_simple_image_array_property("clip", shorthand, image_layers_field, "mClip", struct_name) %>
     <% impl_simple_image_array_property("origin", shorthand, image_layers_field, "mOrigin", struct_name) %>
 
     % for orientation in ["x", "y"]:
     pub fn copy_${shorthand}_position_${orientation}_from(&mut self, other: &Self) {
         use gecko_bindings::structs::nsStyleImageLayers_LayerType as LayerType;
 
         let count = other.gecko.${image_layers_field}.mPosition${orientation.upper()}Count;
@@ -3911,16 +3954,43 @@ fn static_assert() {
         self.clear_text_emphasis_style_if_string();
         if other.gecko.mTextEmphasisStyle == structs::NS_STYLE_TEXT_EMPHASIS_STYLE_STRING as u8 {
             self.gecko.mTextEmphasisStyleString
                       .assign(&*other.gecko.mTextEmphasisStyleString)
         }
         self.gecko.mTextEmphasisStyle = other.gecko.mTextEmphasisStyle;
     }
 
+    pub fn clone_text_emphasis_style(&self) -> longhands::text_emphasis_style::computed_value::T {
+        use properties::longhands::text_emphasis_style::computed_value::{T, KeywordValue};
+        use properties::longhands::text_emphasis_style::ShapeKeyword;
+
+        if self.gecko.mTextEmphasisStyle == structs::NS_STYLE_TEXT_EMPHASIS_STYLE_NONE as u8 {
+            return T::None;
+        } else if self.gecko.mTextEmphasisStyle == structs::NS_STYLE_TEXT_EMPHASIS_STYLE_STRING as u8 {
+            return T::String(self.gecko.mTextEmphasisStyleString.to_string());
+        }
+
+        let fill = self.gecko.mTextEmphasisStyle & structs::NS_STYLE_TEXT_EMPHASIS_STYLE_OPEN as u8 == 0;
+        let shape =
+            match self.gecko.mTextEmphasisStyle as u32 & !structs::NS_STYLE_TEXT_EMPHASIS_STYLE_OPEN {
+                structs::NS_STYLE_TEXT_EMPHASIS_STYLE_DOT => ShapeKeyword::Dot,
+                structs::NS_STYLE_TEXT_EMPHASIS_STYLE_CIRCLE => ShapeKeyword::Circle,
+                structs::NS_STYLE_TEXT_EMPHASIS_STYLE_DOUBLE_CIRCLE => ShapeKeyword::DoubleCircle,
+                structs::NS_STYLE_TEXT_EMPHASIS_STYLE_TRIANGLE => ShapeKeyword::Triangle,
+                structs::NS_STYLE_TEXT_EMPHASIS_STYLE_SESAME => ShapeKeyword::Sesame,
+                x => panic!("Unexpected value in style struct for text-emphasis-style property: {:?}", x)
+            };
+
+        T::Keyword(KeywordValue {
+            fill: fill,
+            shape: shape
+        })
+    }
+
     <%call expr="impl_app_units('_webkit_text_stroke_width', 'mWebkitTextStrokeWidth', need_clone=True)"></%call>
 
     #[allow(non_snake_case)]
     pub fn set__moz_tab_size(&mut self, v: longhands::_moz_tab_size::computed_value::T) {
         use values::Either;
 
         match v {
             Either::Second(number) => {

--- a/servo/components/style/properties/longhand/background.mako.rs
+++ b/servo/components/style/properties/longhand/background.mako.rs
@@ -26,17 +26,17 @@
 % for (axis, direction, initial) in [("x", "Horizontal", "left"), ("y", "Vertical", "top")]:
     ${helpers.predefined_type("background-position-" + axis, "position::" + direction + "Position",
                               initial_value="computed::LengthOrPercentage::zero()",
                               initial_specified_value="SpecifiedValue::initial_specified_value()",
                               spec="https://drafts.csswg.org/css-backgrounds-4/#propdef-background-position-" + axis,
                               animation_value_type="ComputedValue", vector=True, delegate_animate=True)}
 % endfor
 
-<%helpers:vector_longhand name="background-repeat" animation_value_type="none"
+<%helpers:vector_longhand name="background-repeat" animation_value_type="discrete"
                           spec="https://drafts.csswg.org/css-backgrounds/#the-background-repeat">
     use std::fmt;
     use style_traits::ToCss;
 
     define_css_keyword_enum!(RepeatKeyword:
                              "repeat" => Repeat,
                              "space" => Space,
                              "round" => Round,

--- a/servo/components/style/properties/longhand/box.mako.rs
+++ b/servo/components/style/properties/longhand/box.mako.rs
@@ -1869,17 +1869,17 @@
                           "inline block horizontal vertical",
                           products="gecko",
                           gecko_ffi_name="mOrient",
                           gecko_enum_prefix="StyleOrient",
                           spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/-moz-orient)",
                           gecko_inexhaustive="True",
                           animation_value_type="discrete")}
 
-<%helpers:longhand name="will-change" products="gecko" animation_value_type="none"
+<%helpers:longhand name="will-change" products="gecko" animation_value_type="discrete"
                    spec="https://drafts.csswg.org/css-will-change/#will-change">
     use std::fmt;
     use style_traits::ToCss;
     use values::CustomIdent;
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
     no_viewport_percentage!(SpecifiedValue);

--- a/servo/components/style/properties/longhand/inherited_text.mako.rs
+++ b/servo/components/style/properties/longhand/inherited_text.mako.rs
@@ -412,18 +412,18 @@
     "SimpleShadow",
     None,
     vector=True,
     animation_value_type="AnimatedTextShadowList",
     ignored_when_colors_disabled=True,
     spec="https://drafts.csswg.org/css-text-decor-3/#text-shadow-property",
 )}
 
-<%helpers:longhand name="text-emphasis-style" products="gecko" need_clone="True" boxed="True"
-                   animation_value_type="none"
+<%helpers:longhand name="text-emphasis-style" products="gecko" boxed="True"
+                   animation_value_type="discrete"
                    spec="https://drafts.csswg.org/css-text-decor/#propdef-text-emphasis-style">
     use computed_values::writing_mode::T as writing_mode;
     use std::fmt;
     use style_traits::ToCss;
     use unicode_segmentation::UnicodeSegmentation;
 
     no_viewport_percentage!(SpecifiedValue);
 

--- a/servo/components/style/properties/longhand/svg.mako.rs
+++ b/servo/components/style/properties/longhand/svg.mako.rs
@@ -65,17 +65,17 @@
 
 ${helpers.single_keyword("mask-mode",
                          "match-source alpha luminance",
                          vector=True,
                          products="gecko",
                          animation_value_type="discrete",
                          spec="https://drafts.fxtf.org/css-masking/#propdef-mask-mode")}
 
-<%helpers:vector_longhand name="mask-repeat" products="gecko" animation_value_type="none" extra_prefixes="webkit"
+<%helpers:vector_longhand name="mask-repeat" products="gecko" animation_value_type="discrete" extra_prefixes="webkit"
                           spec="https://drafts.fxtf.org/css-masking/#propdef-mask-repeat">
     pub use properties::longhands::background_repeat::single_value::parse;
     pub use properties::longhands::background_repeat::single_value::SpecifiedValue;
     pub use properties::longhands::background_repeat::single_value::computed_value;
     pub use properties::longhands::background_repeat::single_value::RepeatKeyword;
 
     #[inline]
     pub fn get_initial_value() -> computed_value::T {