--- a/layout/style/ServoBindings.cpp
+++ b/layout/style/ServoBindings.cpp
@@ -738,42 +738,45 @@ void
 Gecko_CopyListStyleTypeFrom(nsStyleList* dst, const nsStyleList* src)
 {
   dst->SetCounterStyle(src->GetCounterStyle());
 }
 
 NS_IMPL_HOLDER_FFI_REFCOUNTING(nsIPrincipal, Principal)
 NS_IMPL_HOLDER_FFI_REFCOUNTING(nsIURI, URI)
 
-void
-Gecko_SetMozBinding(nsStyleDisplay* aDisplay,
-                    const uint8_t* aURLString, uint32_t aURLStringLength,
-                    ThreadSafeURIHolder* aBaseURI,
-                    ThreadSafeURIHolder* aReferrer,
-                    ThreadSafePrincipalHolder* aPrincipal)
+already_AddRefed<css::URLValue>
+ServoBundledURI::IntoCssUrl()
 {
-  if (!aURLString) {
-    aDisplay->mBinding = nullptr;
-    return;
+  if (!mURLString) {
+    return nullptr;
   }
 
-  MOZ_ASSERT(aDisplay);
-  MOZ_ASSERT(aBaseURI);
-  MOZ_ASSERT(aReferrer);
-  MOZ_ASSERT(aPrincipal);
+  MOZ_ASSERT(mBaseURI);
+  MOZ_ASSERT(mReferrer);
+  MOZ_ASSERT(mPrincipal);
 
   nsString url;
-  nsDependentCSubstring urlString(reinterpret_cast<const char*>(aURLString),
-                                  aURLStringLength);
+  nsDependentCSubstring urlString(reinterpret_cast<const char*>(mURLString),
+                                  mURLStringLength);
   AppendUTF8toUTF16(urlString, url);
   RefPtr<nsStringBuffer> urlBuffer = nsCSSValue::BufferFromString(url);
 
-  aDisplay->mBinding =
-    new css::URLValue(urlBuffer, do_AddRef(aBaseURI),
-                      do_AddRef(aReferrer), do_AddRef(aPrincipal));
+  RefPtr<css::URLValue> urlValue = new css::URLValue(urlBuffer,
+                                                     do_AddRef(mBaseURI),
+                                                     do_AddRef(mReferrer),
+                                                     do_AddRef(mPrincipal));
+  return urlValue.forget();
+}
+
+void
+Gecko_SetMozBinding(nsStyleDisplay* aDisplay, ServoBundledURI aBundledURI)
+{
+    MOZ_ASSERT(aDisplay);
+    aDisplay->mBinding = aBundledURI.IntoCssUrl();
 }
 
 void
 Gecko_CopyMozBindingFrom(nsStyleDisplay* aDest, const nsStyleDisplay* aSrc)
 {
   aDest->mBinding = aSrc->mBinding;
 }
 
@@ -901,25 +904,22 @@ Gecko_CreateGradient(uint8_t aShape,
 void
 Gecko_SetListStyleImageNone(nsStyleList* aList)
 {
   aList->mListStyleImage = nullptr;
 }
 
 void
 Gecko_SetListStyleImage(nsStyleList* aList,
-                        const uint8_t* aURLString, uint32_t aURLStringLength,
-                        ThreadSafeURIHolder* aBaseURI,
-                        ThreadSafeURIHolder* aReferrer,
-                        ThreadSafePrincipalHolder* aPrincipal)
+                        ServoBundledURI aURI)
 {
   aList->mListStyleImage =
     CreateStyleImageRequest(nsStyleImageRequest::Mode(0),
-                            aURLString, aURLStringLength,
-                            aBaseURI, aReferrer, aPrincipal);
+                            aURI.mURLString, aURI.mURLStringLength,
+                            aURI.mBaseURI, aURI.mReferrer, aURI.mPrincipal);
 }
 
 void
 Gecko_CopyListStyleImageFrom(nsStyleList* aList, const nsStyleList* aSource)
 {
   aList->mListStyleImage = aSource->mListStyleImage;
 }
 

--- a/layout/style/ServoBindings.h
+++ b/layout/style/ServoBindings.h
@@ -30,16 +30,19 @@ class nsIAtom;
 class nsIPrincipal;
 class nsIURI;
 struct nsFont;
 namespace mozilla {
   class ServoStyleSheet;
   class FontFamilyList;
   enum FontFamilyType : uint32_t;
   struct Keyframe;
+  namespace css {
+    struct URLValue;
+  };
 }
 using mozilla::FontFamilyList;
 using mozilla::FontFamilyType;
 using mozilla::ServoElementSnapshot;
 struct nsMediaFeature;
 struct nsStyleList;
 struct nsStyleImage;
 struct nsStyleGradientStop;
@@ -80,16 +83,27 @@ DEFINE_ARRAY_TYPE_FOR(uintptr_t);
 #undef DEFINE_ARRAY_TYPE_FOR
 
 extern "C" {
 
 // Object refcounting.
 NS_DECL_HOLDER_FFI_REFCOUNTING(nsIPrincipal, Principal)
 NS_DECL_HOLDER_FFI_REFCOUNTING(nsIURI, URI)
 
+class ServoBundledURI
+{
+public:
+  already_AddRefed<mozilla::css::URLValue> IntoCssUrl();
+  const uint8_t* mURLString;
+  uint32_t mURLStringLength;
+  ThreadSafeURIHolder* mBaseURI;
+  ThreadSafeURIHolder* mReferrer;
+  ThreadSafePrincipalHolder* mPrincipal;
+};
+
 // DOM Traversal.
 uint32_t Gecko_ChildrenCount(RawGeckoNodeBorrowed node);
 bool Gecko_NodeIsElement(RawGeckoNodeBorrowed node);
 bool Gecko_IsInDocument(RawGeckoNodeBorrowed node);
 bool Gecko_FlattenedTreeParentIsParent(RawGeckoNodeBorrowed node);
 RawGeckoNodeBorrowedOrNull Gecko_GetParentNode(RawGeckoNodeBorrowed node);
 RawGeckoNodeBorrowedOrNull Gecko_GetFirstChild(RawGeckoNodeBorrowed node);
 RawGeckoNodeBorrowedOrNull Gecko_GetLastChild(RawGeckoNodeBorrowed node);
@@ -201,38 +215,31 @@ nsStyleGradient* Gecko_CreateGradient(ui
                                       uint8_t size,
                                       bool repeating,
                                       bool legacy_syntax,
                                       uint32_t stops);
 
 // list-style-image style.
 void Gecko_SetListStyleImageNone(nsStyleList* style_struct);
 void Gecko_SetListStyleImage(nsStyleList* style_struct,
-                             const uint8_t* string_bytes, uint32_t string_length,
-                             ThreadSafeURIHolder* base_uri,
-                             ThreadSafeURIHolder* referrer,
-                             ThreadSafePrincipalHolder* principal);
+                             ServoBundledURI uri);
 void Gecko_CopyListStyleImageFrom(nsStyleList* dest, const nsStyleList* src);
 
 // cursor style.
 void Gecko_SetCursorArrayLength(nsStyleUserInterface* ui, size_t len);
 void Gecko_SetCursorImage(nsCursorImage* cursor,
                           const uint8_t* string_bytes, uint32_t string_length,
                           ThreadSafeURIHolder* base_uri,
                           ThreadSafeURIHolder* referrer,
                           ThreadSafePrincipalHolder* principal);
 void Gecko_CopyCursorArrayFrom(nsStyleUserInterface* dest,
                                const nsStyleUserInterface* src);
 
 // Display style.
-void Gecko_SetMozBinding(nsStyleDisplay* style_struct,
-                         const uint8_t* string_bytes, uint32_t string_length,
-                         ThreadSafeURIHolder* base_uri,
-                         ThreadSafeURIHolder* referrer,
-                         ThreadSafePrincipalHolder* principal);
+void Gecko_SetMozBinding(nsStyleDisplay* style_struct, ServoBundledURI bundled_uri);
 void Gecko_CopyMozBindingFrom(nsStyleDisplay* des, const nsStyleDisplay* src);
 
 // Dirtiness tracking.
 uint32_t Gecko_GetNodeFlags(RawGeckoNodeBorrowed node);
 void Gecko_SetNodeFlags(RawGeckoNodeBorrowed node, uint32_t flags);
 void Gecko_UnsetNodeFlags(RawGeckoNodeBorrowed node, uint32_t flags);
 void Gecko_SetOwnerDocumentNeedsStyleFlush(RawGeckoElementBorrowed element);