--- a/layout/style/nsCSSValue.cpp
+++ b/layout/style/nsCSSValue.cpp
@@ -1678,57 +1678,16 @@ size_t
 css::ImageValue::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
 {
   size_t n = aMallocSizeOf(this);
   n += css::URLValueData::SizeOfExcludingThis(aMallocSizeOf);
   n += mRequests.ShallowSizeOfExcludingThis(aMallocSizeOf);
   return n;
 }
 
-// --- nsCSSCornerSizes -----------------
-
-nsCSSCornerSizes::nsCSSCornerSizes(void)
-{
-  MOZ_COUNT_CTOR(nsCSSCornerSizes);
-}
-
-nsCSSCornerSizes::nsCSSCornerSizes(const nsCSSCornerSizes& aCopy)
-  : mTopLeft(aCopy.mTopLeft),
-    mTopRight(aCopy.mTopRight),
-    mBottomRight(aCopy.mBottomRight),
-    mBottomLeft(aCopy.mBottomLeft)
-{
-  MOZ_COUNT_CTOR(nsCSSCornerSizes);
-}
-
-nsCSSCornerSizes::~nsCSSCornerSizes()
-{
-  MOZ_COUNT_DTOR(nsCSSCornerSizes);
-}
-
-void
-nsCSSCornerSizes::Reset()
-{
-  NS_FOR_CSS_FULL_CORNERS(corner) {
-    this->GetCorner(corner).Reset();
-  }
-}
-
-static_assert(eCornerTopLeft == 0 && eCornerTopRight == 1 &&
-              eCornerBottomRight == 2 && eCornerBottomLeft == 3,
-              "box corner constants not tl/tr/br/bl == 0/1/2/3");
-
-/* static */ const nsCSSCornerSizes::corner_type
-nsCSSCornerSizes::corners[4] = {
-  &nsCSSCornerSizes::mTopLeft,
-  &nsCSSCornerSizes::mTopRight,
-  &nsCSSCornerSizes::mBottomRight,
-  &nsCSSCornerSizes::mBottomLeft,
-};
-
 size_t
 mozilla::css::GridTemplateAreasValue::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
 {
   // Only measure it if it's unshared, to avoid double-counting.
   size_t n = 0;
   if (mRefCnt <= 1) {
     n += aMallocSizeOf(this);
     n += mNamedAreas.ShallowSizeOfExcludingThis(aMallocSizeOf);

--- a/layout/style/nsCSSValue.h
+++ b/layout/style/nsCSSValue.h
@@ -1264,59 +1264,10 @@ nsCSSValue::GetPairListValue() const
   if (mUnit == eCSSUnit_PairList)
     return mValue.mPairList;
   else {
     MOZ_ASSERT (mUnit == eCSSUnit_PairListDep, "not a pairlist value");
     return mValue.mPairListDependent;
   }
 }
 
-struct nsCSSCornerSizes {
-  nsCSSCornerSizes(void);
-  nsCSSCornerSizes(const nsCSSCornerSizes& aCopy);
-  ~nsCSSCornerSizes();
-
-  // argument is a "full corner" constant from nsStyleConsts.h
-  nsCSSValue const & GetCorner(uint32_t aCorner) const {
-    return this->*corners[aCorner];
-  }
-  nsCSSValue & GetCorner(uint32_t aCorner) {
-    return this->*corners[aCorner];
-  }
-
-  bool operator==(const nsCSSCornerSizes& aOther) const {
-    NS_FOR_CSS_FULL_CORNERS(corner) {
-      if (this->GetCorner(corner) != aOther.GetCorner(corner))
-        return false;
-    }
-    return true;
-  }
-
-  bool operator!=(const nsCSSCornerSizes& aOther) const {
-    NS_FOR_CSS_FULL_CORNERS(corner) {
-      if (this->GetCorner(corner) != aOther.GetCorner(corner))
-        return true;
-    }
-    return false;
-  }
-
-  bool HasValue() const {
-    NS_FOR_CSS_FULL_CORNERS(corner) {
-      if (this->GetCorner(corner).GetUnit() != eCSSUnit_Null)
-        return true;
-    }
-    return false;
-  }
-
-  void Reset();
-
-  nsCSSValue mTopLeft;
-  nsCSSValue mTopRight;
-  nsCSSValue mBottomRight;
-  nsCSSValue mBottomLeft;
-
-protected:
-  typedef nsCSSValue nsCSSCornerSizes::*corner_type;
-  static const corner_type corners[4];
-};
-
 #endif /* nsCSSValue_h___ */