--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -2190,17 +2190,17 @@ nsStyleImage::ComputeActualCropRect(nsIn
     *aIsEntireImage = aActualCropRect.IsEqualInterior(imageRect);
   }
   return true;
 }
 
 nsresult
 nsStyleImage::StartDecoding() const
 {
-  if ((mType == eStyleImageType_Image) && mImage) {
+  if (mType == eStyleImageType_Image) {
     return mImage->StartDecoding();
   }
   return NS_OK;
 }
 
 bool
 nsStyleImage::IsOpaque() const
 {

--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -359,16 +359,17 @@ struct nsStyleImage
   void SetElementId(const char16_t* aElementId);
   void SetCropRect(mozilla::UniquePtr<nsStyleSides> aCropRect);
 
   nsStyleImageType GetType() const {
     return mType;
   }
   imgRequestProxy* GetImageData() const {
     MOZ_ASSERT(mType == eStyleImageType_Image, "Data is not an image!");
+    MOZ_ASSERT(mImage);
     MOZ_ASSERT(mImageTracked,
                "Should be tracking any image we're going to use!");
     return mImage;
   }
   nsStyleGradient* GetGradientData() const {
     NS_ASSERTION(mType == eStyleImageType_Gradient, "Data is not a gradient!");
     return mGradient;
   }