--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -458,16 +458,19 @@ struct nsStyleImage
   }
   imgRequestProxy* GetImageData() const {
     return GetImageRequest()->get();
   }
   nsStyleGradient* GetGradientData() const {
     NS_ASSERTION(mType == eStyleImageType_Gradient, "Data is not a gradient!");
     return mGradient;
   }
+  bool IsResolved() const {
+    return mType != eStyleImageType_Image || GetImageRequest()->IsResolved();
+  }
   const nsIAtom* GetElementId() const {
     NS_ASSERTION(mType == eStyleImageType_Element, "Data is not an element!");
     return mElementId;
   }
   const mozilla::UniquePtr<nsStyleSides>& GetCropRect() const {
     NS_ASSERTION(mType == eStyleImageType_Image,
                  "Only image data can have a crop rect");
     return mCropRect;