--- a/servo/components/style/properties/helpers/animated_properties.mako.rs
+++ b/servo/components/style/properties/helpers/animated_properties.mako.rs
@@ -61,16 +61,29 @@ impl TransitionProperty {
     pub fn each<F: FnMut(TransitionProperty) -> ()>(mut cb: F) {
         % for prop in data.longhands:
             % if prop.animatable:
                 cb(TransitionProperty::${prop.camel_case});
             % endif
         % endfor
     }
 
+    /// Iterates over each property that is not `All`, and will return true if any of the cb
+    /// returns true.
+    pub fn any<F: FnMut(TransitionProperty) -> bool>(mut cb: F) -> bool {
+        % for prop in data.longhands:
+            % if prop.animatable:
+                if cb(TransitionProperty::${prop.camel_case}) {
+                    return true;
+                }
+            % endif
+        % endfor
+        false
+    }
+
     /// Parse a transition-property value.
     pub fn parse(input: &mut Parser) -> Result<Self, ()> {
         match_ignore_ascii_case! { &try!(input.expect_ident()),
             "all" => Ok(TransitionProperty::All),
             % for prop in data.longhands:
                 % if prop.animatable:
                     "${prop.name}" => Ok(TransitionProperty::${prop.camel_case}),
                 % endif