--- a/servo/components/style/stylesheets/counter_style_rule.rs
+++ b/servo/components/style/stylesheets/counter_style_rule.rs
@@ -5,8 +5,20 @@
 // TODO(emilio): unify this, components/style/counter_style.rs, and
 // components/style/gecko/rules.rs
 #![allow(missing_docs)]
 
 #[cfg(feature = "servo")]
 pub use counter_style::CounterStyleRuleData as CounterStyleRule;
 #[cfg(feature = "gecko")]
 pub use gecko::rules::CounterStyleRule;
+
+impl CounterStyleRule {
+    #[cfg(feature = "servo")]
+    pub fn clone_conditionally_gecko_or_servo(&self) -> CounterStyleRule {
+        self.clone()
+    }
+
+    #[cfg(feature = "gecko")]
+    pub fn clone_conditionally_gecko_or_servo(&self) -> CounterStyleRule {
+        self.deep_clone_from_gecko()
+    }
+}
\ No newline at end of file

--- a/servo/components/style/stylesheets/font_face_rule.rs
+++ b/servo/components/style/stylesheets/font_face_rule.rs
@@ -5,8 +5,20 @@
 // TODO(emilio): unify this, components/style/font_face.rs, and
 // components/style/gecko/rules.rs
 #![allow(missing_docs)]
 
 #[cfg(feature = "servo")]
 pub use font_face::FontFaceRuleData as FontFaceRule;
 #[cfg(feature = "gecko")]
 pub use gecko::rules::FontFaceRule;
+
+impl FontFaceRule {
+    #[cfg(feature = "servo")]
+    pub fn clone_conditionally_gecko_or_servo(&self) -> FontFaceRule {
+        self.clone()
+    }
+
+    #[cfg(feature = "gecko")]
+    pub fn clone_conditionally_gecko_or_servo(&self) -> FontFaceRule {
+        self.deep_clone_from_gecko()
+    }
+}
\ No newline at end of file

--- a/servo/components/style/stylesheets/mod.rs
+++ b/servo/components/style/stylesheets/mod.rs
@@ -285,30 +285,22 @@ impl DeepCloneWithLock for CssRule {
             CssRule::Media(ref arc) => {
                 let rule = arc.read_with(guard);
                 CssRule::Media(Arc::new(
                     lock.wrap(rule.deep_clone_with_lock(lock, guard))))
             },
             CssRule::FontFace(ref arc) => {
                 let rule = arc.read_with(guard);
                 CssRule::FontFace(Arc::new(lock.wrap(
-                    if cfg!(feature = "gecko") {
-                        rule.deep_clone_from_gecko()
-                    } else {
-                        rule.clone()
-                    })))
+                    rule.clone_conditionally_gecko_or_servo())))
             },
             CssRule::CounterStyle(ref arc) => {
                 let rule = arc.read_with(guard);
                 CssRule::CounterStyle(Arc::new(lock.wrap(
-                    if cfg!(feature = "gecko") {
-                        rule.deep_clone_from_gecko()
-                    } else {
-                        rule.clone()
-                    })))
+                    rule.clone_conditionally_gecko_or_servo())))
             },
             CssRule::Viewport(ref arc) => {
                 let rule = arc.read_with(guard);
                 CssRule::Viewport(Arc::new(lock.wrap(rule.clone())))
             },
             CssRule::Keyframes(ref arc) => {
                 let rule = arc.read_with(guard);
                 CssRule::Keyframes(Arc::new(