--- a/layout/style/ServoBindings.cpp
+++ b/layout/style/ServoBindings.cpp
@@ -1894,16 +1894,24 @@ Gecko_CSSValue_GetArrayItem(nsCSSValueBo
 }
 
 nsCSSValueBorrowed
 Gecko_CSSValue_GetArrayItemConst(nsCSSValueBorrowed aCSSValue, int32_t aIndex)
 {
   return &aCSSValue->GetArrayValue()->Item(aIndex);
 }
 
+void
+Gecko_CSSValue_SetPair(nsCSSValueBorrowedMut aCSSValue,
+                       nsCSSValueBorrowed aXValue, nsCSSValueBorrowed aYValue)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  aCSSValue->SetPairValue(*aXValue, *aYValue);
+}
+
 
 bool
 Gecko_PropertyId_IsPrefEnabled(nsCSSPropertyID id)
 {
   return nsCSSProps::IsEnabled(id);
 }
 
 void

--- a/layout/style/ServoBindings.h
+++ b/layout/style/ServoBindings.h
@@ -479,16 +479,18 @@ void Gecko_CSSValue_SetString(nsCSSValue
                               const uint8_t* string, uint32_t len, nsCSSUnit unit);
 void Gecko_CSSValue_SetStringFromAtom(nsCSSValueBorrowedMut css_value,
                                       nsIAtom* atom, nsCSSUnit unit);
 // Take an addrefed nsIAtom and set it to the nsCSSValue
 void Gecko_CSSValue_SetAtomIdent(nsCSSValueBorrowedMut css_value, nsIAtom* atom);
 void Gecko_CSSValue_SetArray(nsCSSValueBorrowedMut css_value, int32_t len);
 void Gecko_CSSValue_SetURL(nsCSSValueBorrowedMut css_value, ServoBundledURI uri);
 void Gecko_CSSValue_SetInt(nsCSSValueBorrowedMut css_value, int32_t integer, nsCSSUnit unit);
+void Gecko_CSSValue_SetPair(nsCSSValueBorrowedMut css_value,
+                            nsCSSValueBorrowed xvalue, nsCSSValueBorrowed yvalue);
 void Gecko_CSSValue_Drop(nsCSSValueBorrowedMut css_value);
 NS_DECL_THREADSAFE_FFI_REFCOUNTING(nsCSSValueSharedList, CSSValueSharedList);
 bool Gecko_PropertyId_IsPrefEnabled(nsCSSPropertyID id);
 
 void Gecko_nsStyleFont_SetLang(nsStyleFont* font, nsIAtom* atom);
 void Gecko_nsStyleFont_CopyLangFrom(nsStyleFont* aFont, const nsStyleFont* aSource);
 void Gecko_nsStyleFont_FixupNoneGeneric(nsStyleFont* font,
                                         RawGeckoPresContextBorrowed pres_context);