diff --git a/layout/style/nsRuleNode.cpp b/layout/style/nsRuleNode.cpp
index a01d295eb6ad..abd726b8dd60 100644
--- a/layout/style/nsRuleNode.cpp
+++ b/layout/style/nsRuleNode.cpp
@@ -1411,7 +1411,7 @@ static void SetStyleImage(nsStyleContext* aStyleContext,
                  isLocalRef,
                  "unexpected unit; maybe nsCSSValue::Image::Image() failed?");
 #endif
-
+      aResult.SetURLValue(do_AddRef(aValue.GetURLStructValue()));
       break;
     }
     default:
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index dcffd6355dec..6a6bc4ab06a5 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -2194,6 +2194,8 @@ nsStyleImage::DoCopy(const nsStyleImage& aOther)
     SetGradientData(aOther.mGradient);
   } else if (aOther.mType == eStyleImageType_Element) {
     SetElementId(aOther.mElementId);
+  } else if (aOther.mType == eStyleImageType_URL) {
+    SetURLValue(do_AddRef(aOther.mURLValue));
   }
 
   UniquePtr<nsStyleSides> cropRectCopy;
@@ -2212,6 +2214,8 @@ nsStyleImage::SetNull()
     NS_RELEASE(mImage);
   } else if (mType == eStyleImageType_Element) {
     free(mElementId);
+  } else if (mType == eStyleImageType_URL) {
+    NS_RELEASE(mURLValue);
   }
 
   mType = eStyleImageType_Null;
@@ -2272,6 +2276,21 @@ nsStyleImage::SetCropRect(UniquePtr<nsStyleSides> aCropRect)
     mCropRect = Move(aCropRect);
 }
 
+void
+nsStyleImage::SetURLValue(already_AddRefed<URLValue> aValue)
+{
+  RefPtr<URLValue> value = aValue;
+
+  if (mType != eStyleImageType_Null) {
+    SetNull();
+  }
+
+  if (value) {
+    mURLValue = value.forget().take();
+    mType = eStyleImageType_URL;
+  }
+}
+
 static int32_t
 ConvertToPixelCoord(const nsStyleCoord& aCoord, int32_t aPercentScale)
 {
@@ -2417,6 +2436,7 @@ nsStyleImage::IsComplete() const
       return false;
     case eStyleImageType_Gradient:
     case eStyleImageType_Element:
+    case eStyleImageType_URL:
       return true;
     case eStyleImageType_Image: {
       imgRequestProxy* req = GetImageData();
@@ -2442,6 +2462,7 @@ nsStyleImage::IsLoaded() const
       return false;
     case eStyleImageType_Gradient:
     case eStyleImageType_Element:
+    case eStyleImageType_URL:
       return true;
     case eStyleImageType_Image: {
       imgRequestProxy* req = GetImageData();
@@ -2489,6 +2510,10 @@ nsStyleImage::operator==(const nsStyleImage& aOther) const
     return NS_strcmp(mElementId, aOther.mElementId) == 0;
   }
 
+  if (mType == eStyleImageType_URL) {
+    return DefinitelyEqualURIs(mURLValue, aOther.mURLValue);
+  }
+
   return true;
 }
 
@@ -2523,6 +2548,18 @@ nsStyleImage::GetImageURI() const
   return uri.forget();
 }
 
+css::URLValueData*
+nsStyleImage::GetURLValue() const
+{
+  if (mType == eStyleImageType_Image) {
+    return mImage->GetImageValue();
+  } else if (mType == eStyleImageType_URL) {
+    return mURLValue;
+  }
+
+  return nullptr;
+}
+
 // --------------------
 // nsStyleImageLayers
 //
diff --git a/layout/style/nsStyleStruct.h b/layout/style/nsStyleStruct.h
index faca7fe05a08..1f1f09473388 100644
--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -305,6 +305,8 @@ private:
 class nsStyleImageRequest
 {
 public:
+  typedef mozilla::css::URLValueData URLValueData;
+
   // Flags describing whether the imgRequestProxy must be tracked in the
   // ImageTracker, whether LockImage/UnlockImage calls will be made
   // when obtaining and releasing the imgRequestProxy, and whether
@@ -360,7 +362,6 @@ public:
   mozilla::css::ImageValue* GetImageValue() const { return mImageValue; }
 
   already_AddRefed<nsIURI> GetImageURI() const;
-
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(nsStyleImageRequest);
 
 private:
@@ -386,7 +387,8 @@ enum nsStyleImageType {
   eStyleImageType_Null,
   eStyleImageType_Image,
   eStyleImageType_Gradient,
-  eStyleImageType_Element
+  eStyleImageType_Element,
+  eStyleImageType_URL
 };
 
 struct CachedBorderImageData
@@ -419,6 +421,9 @@ private:
  */
 struct nsStyleImage
 {
+  typedef mozilla::css::URLValue     URLValue;
+  typedef mozilla::css::URLValueData URLValueData;
+
   nsStyleImage();
   ~nsStyleImage();
   nsStyleImage(const nsStyleImage& aOther);
@@ -429,6 +434,7 @@ struct nsStyleImage
   void SetGradientData(nsStyleGradient* aGradient);
   void SetElementId(const char16_t* aElementId);
   void SetCropRect(mozilla::UniquePtr<nsStyleSides> aCropRect);
+  void SetURLValue(already_AddRefed<URLValue> aData);
 
   void ResolveImage(nsPresContext* aContext) {
     MOZ_ASSERT(mType != eStyleImageType_Image || mImage);
@@ -464,6 +470,8 @@ struct nsStyleImage
 
   already_AddRefed<nsIURI> GetImageURI() const;
 
+  URLValueData* GetURLValue() const;
+
   /**
    * Compute the actual crop rect in pixels, using the source image bounds.
    * The computation involves converting percentage unit to pixel unit and
@@ -547,6 +555,9 @@ private:
   union {
     nsStyleImageRequest* mImage;
     nsStyleGradient* mGradient;
+    URLValue* mURLValue; // See the comment in SetStyleImage's 'case
+                         // eCSSUnit_URL' section to know why we need to
+                         // store URLValues separately from mImage.
     char16_t* mElementId;
   };