Issue #2241 - Part 4.1: Get DOMPoint, DOMQuad, DOMRect, DOMMatrix a bit closer to spec.

Backported from Mozilla bug 1186265's part 1.

8 files changed, 227 insertions, 186 deletions

diff --git a/dom/base/DOMMatrix.cpp b/dom/base/DOMMatrix.cpp
index 72c8d9b76b..1631f2cdcf 100644
--- a/dom/base/DOMMatrix.cpp
+++ b/dom/base/DOMMatrix.cpp
@@ -20,6 +20,10 @@
 namespace mozilla {
 namespace dom {
 
+template <typename T>
+static void
+SetDataInMatrix(DOMMatrixReadOnly* aMatrix, const T* aData, int aLength, ErrorResult& aRv);
+
 static const double radPerDegree = 2.0 * M_PI / 360.0;
 
 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DOMMatrixReadOnly, mParent)
@@ -27,6 +31,39 @@ NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DOMMatrixReadOnly, mParent)
 NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(DOMMatrixReadOnly, AddRef)
 NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(DOMMatrixReadOnly, Release)
 
+JSObject*
+DOMMatrixReadOnly::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return DOMMatrixReadOnlyBinding::Wrap(aCx, this, aGivenProto);
+}
+
+already_AddRefed<DOMMatrixReadOnly>
+DOMMatrixReadOnly::Constructor(
+  const GlobalObject& aGlobal,
+  const Optional<StringOrUnrestrictedDoubleSequence>& aArg,
+  ErrorResult& aRv)
+{
+  RefPtr<DOMMatrixReadOnly> rval = new DOMMatrixReadOnly(aGlobal.GetAsSupports());
+  if (!aArg.WasPassed()) {
+    return rval.forget();
+  }
+
+  const auto& arg = aArg.Value();
+  if (arg.IsString()) {
+    nsCOMPtr<nsPIDOMWindowInner> win = do_QueryInterface(aGlobal.GetAsSupports());
+    if (!win) {
+      aRv.ThrowTypeError<MSG_ILLEGAL_CONSTRUCTOR>();
+      return nullptr;
+    }
+    rval->SetMatrixValue(arg.GetAsString(), aRv);
+  } else {
+    const auto& sequence = arg.GetAsUnrestrictedDoubleSequence();
+    SetDataInMatrix(rval, sequence.Elements(), sequence.Length(), aRv);
+  }
+
+  return rval.forget();
+}
+
 already_AddRefed<DOMMatrix>
 DOMMatrixReadOnly::Translate(double aTx,
                              double aTy,
@@ -330,7 +367,9 @@ DOMMatrix::Constructor(const GlobalObject& aGlobal, const DOMMatrixReadOnly& aOt
   return obj.forget();
 }
 
-template <typename T> void SetDataInMatrix(DOMMatrix* aMatrix, const T* aData, int aLength, ErrorResult& aRv)
+template <typename T>
+static void
+SetDataInMatrix(DOMMatrixReadOnly* aMatrix, const T* aData, int aLength, ErrorResult& aRv)
 {
   if (aLength == 16) {
     aMatrix->SetM11(aData[0]);
@@ -357,7 +396,9 @@ template <typename T> void SetDataInMatrix(DOMMatrix* aMatrix, const T* aData, i
     aMatrix->SetE(aData[4]);
     aMatrix->SetF(aData[5]);
   } else {
-    aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
+    nsAutoString lengthStr;
+    lengthStr.AppendInt(aLength);
+    aRv.ThrowTypeError<MSG_MATRIX_INIT_LENGTH_WRONG>(lengthStr);
   }
 }
 
@@ -390,7 +431,8 @@ DOMMatrix::Constructor(const GlobalObject& aGlobal, const Sequence<double>& aNum
   return obj.forget();
 }
 
-void DOMMatrix::Ensure3DMatrix()
+void
+DOMMatrixReadOnly::Ensure3DMatrix()
 {
   if (!mMatrix3D) {
     mMatrix3D = new gfx::Matrix4x4(gfx::Matrix4x4::From2D(*mMatrix2D));
@@ -617,8 +659,8 @@ DOMMatrix::InvertSelf()
   return this;
 }
 
-DOMMatrix*
-DOMMatrix::SetMatrixValue(const nsAString& aTransformList, ErrorResult& aRv)
+DOMMatrixReadOnly*
+DOMMatrixReadOnly::SetMatrixValue(const nsAString& aTransformList, ErrorResult& aRv)
 {
   SVGTransformListParser parser(aTransformList);
   if (!parser.Parse()) {
@@ -644,6 +686,13 @@ DOMMatrix::SetMatrixValue(const nsAString& aTransformList, ErrorResult& aRv)
   return this;
 }
 
+DOMMatrix*
+DOMMatrix::SetMatrixValue(const nsAString& aTransformList, ErrorResult& aRv)
+{
+  DOMMatrixReadOnly::SetMatrixValue(aTransformList, aRv);
+  return this;
+}
+
 JSObject*
 DOMMatrix::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
 {
diff --git a/dom/base/DOMMatrix.h b/dom/base/DOMMatrix.h
index 9b83548efa..e956878c20 100644
--- a/dom/base/DOMMatrix.h
+++ b/dom/base/DOMMatrix.h
@@ -22,6 +22,7 @@ namespace dom {
 class GlobalObject;
 class DOMMatrix;
 class DOMPoint;
+class StringOrUnrestrictedDoubleSequence;
 struct DOMPointInit;
 
 class DOMMatrixReadOnly : public nsWrapperCache
@@ -51,6 +52,12 @@ public:
   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(DOMMatrixReadOnly)
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(DOMMatrixReadOnly)
 
+  nsISupports* GetParentObject() const { return mParent; }
+  virtual JSObject* WrapObject(JSContext* cx, JS::Handle<JSObject*> aGivenProto) override;
+
+  static already_AddRefed<DOMMatrixReadOnly>
+  Constructor(const GlobalObject& aGlobal, const Optional<StringOrUnrestrictedDoubleSequence>& aArg, ErrorResult& aRv);
+
 #define GetMatrixMember(entry2D, entry3D, default) \
 { \
   if (mMatrix3D) { \
@@ -94,6 +101,51 @@ public:
 #undef GetMatrixMember
 #undef Get3DMatrixMember
 
+  // Defined here so we can construct DOMMatrixReadOnly objects.
+#define Set2DMatrixMember(entry2D, entry3D) \
+{ \
+  if (mMatrix3D) { \
+    mMatrix3D->entry3D = v; \
+  } else { \
+    mMatrix2D->entry2D = v; \
+  } \
+}
+
+#define Set3DMatrixMember(entry3D, default) \
+{ \
+  if (mMatrix3D || (v != default)) { \
+    Ensure3DMatrix(); \
+    mMatrix3D->entry3D = v; \
+  } \
+}
+
+  void SetA(double v) Set2DMatrixMember(_11, _11)
+  void SetB(double v) Set2DMatrixMember(_12, _12)
+  void SetC(double v) Set2DMatrixMember(_21, _21)
+  void SetD(double v) Set2DMatrixMember(_22, _22)
+  void SetE(double v) Set2DMatrixMember(_31, _41)
+  void SetF(double v) Set2DMatrixMember(_32, _42)
+
+  void SetM11(double v) Set2DMatrixMember(_11, _11)
+  void SetM12(double v) Set2DMatrixMember(_12, _12)
+  void SetM13(double v) Set3DMatrixMember(_13, 0)
+  void SetM14(double v) Set3DMatrixMember(_14, 0)
+  void SetM21(double v) Set2DMatrixMember(_21, _21)
+  void SetM22(double v) Set2DMatrixMember(_22, _22)
+  void SetM23(double v) Set3DMatrixMember(_23, 0)
+  void SetM24(double v) Set3DMatrixMember(_24, 0)
+  void SetM31(double v) Set3DMatrixMember(_31, 0)
+  void SetM32(double v) Set3DMatrixMember(_32, 0)
+  void SetM33(double v) Set3DMatrixMember(_33, 1.0)
+  void SetM34(double v) Set3DMatrixMember(_34, 0)
+  void SetM41(double v) Set2DMatrixMember(_31, _41)
+  void SetM42(double v) Set2DMatrixMember(_32, _42)
+  void SetM43(double v) Set3DMatrixMember(_43, 0)
+  void SetM44(double v) Set3DMatrixMember(_44, 1.0)
+
+#undef Set2DMatrixMember
+#undef Set3DMatrixMember
+
   already_AddRefed<DOMMatrix> Translate(double aTx,
                                         double aTy,
                                         double aTz = 0) const;
@@ -143,6 +195,9 @@ protected:
 
   virtual ~DOMMatrixReadOnly() {}
 
+  DOMMatrixReadOnly* SetMatrixValue(const nsAString& aTransformList, ErrorResult& aRv);
+  void Ensure3DMatrix();
+
 private:
   DOMMatrixReadOnly() = delete;
   DOMMatrixReadOnly(const DOMMatrixReadOnly&) = delete;
@@ -177,53 +232,8 @@ public:
   static already_AddRefed<DOMMatrix>
   Constructor(const GlobalObject& aGlobal, const Sequence<double>& aNumberSequence, ErrorResult& aRv);
 
-  nsISupports* GetParentObject() const { return mParent; }
   virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
 
-#define Set2DMatrixMember(entry2D, entry3D) \
-{ \
-  if (mMatrix3D) { \
-    mMatrix3D->entry3D = v; \
-  } else { \
-    mMatrix2D->entry2D = v; \
-  } \
-}
-
-#define Set3DMatrixMember(entry3D, default) \
-{ \
-  if (mMatrix3D || (v != default)) { \
-    Ensure3DMatrix(); \
-    mMatrix3D->entry3D = v; \
-  } \
-}
-
-  void SetA(double v) Set2DMatrixMember(_11, _11)
-  void SetB(double v) Set2DMatrixMember(_12, _12)
-  void SetC(double v) Set2DMatrixMember(_21, _21)
-  void SetD(double v) Set2DMatrixMember(_22, _22)
-  void SetE(double v) Set2DMatrixMember(_31, _41)
-  void SetF(double v) Set2DMatrixMember(_32, _42)
-
-  void SetM11(double v) Set2DMatrixMember(_11, _11)
-  void SetM12(double v) Set2DMatrixMember(_12, _12)
-  void SetM13(double v) Set3DMatrixMember(_13, 0)
-  void SetM14(double v) Set3DMatrixMember(_14, 0)
-  void SetM21(double v) Set2DMatrixMember(_21, _21)
-  void SetM22(double v) Set2DMatrixMember(_22, _22)
-  void SetM23(double v) Set3DMatrixMember(_23, 0)
-  void SetM24(double v) Set3DMatrixMember(_24, 0)
-  void SetM31(double v) Set3DMatrixMember(_31, 0)
-  void SetM32(double v) Set3DMatrixMember(_32, 0)
-  void SetM33(double v) Set3DMatrixMember(_33, 1.0)
-  void SetM34(double v) Set3DMatrixMember(_34, 0)
-  void SetM41(double v) Set2DMatrixMember(_31, _41)
-  void SetM42(double v) Set2DMatrixMember(_32, _42)
-  void SetM43(double v) Set3DMatrixMember(_43, 0)
-  void SetM44(double v) Set3DMatrixMember(_44, 1.0)
-
-#undef Set2DMatrixMember
-#undef Set3DMatrixMember
-
   DOMMatrix* MultiplySelf(const DOMMatrix& aOther);
   DOMMatrix* PreMultiplySelf(const DOMMatrix& aOther);
   DOMMatrix* TranslateSelf(double aTx,
@@ -255,8 +265,6 @@ public:
   DOMMatrix* SkewYSelf(double aSy);
   DOMMatrix* InvertSelf();
   DOMMatrix* SetMatrixValue(const nsAString& aTransformList, ErrorResult& aRv);
-protected:
-  void Ensure3DMatrix();
 
   virtual ~DOMMatrix() {}
 };
diff --git a/dom/base/DOMPoint.cpp b/dom/base/DOMPoint.cpp
index 97eec9e766..508bfab1e2 100644
--- a/dom/base/DOMPoint.cpp
+++ b/dom/base/DOMPoint.cpp
@@ -16,9 +16,32 @@ NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DOMPointReadOnly, mParent)
 NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(DOMPointReadOnly, AddRef)
 NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(DOMPointReadOnly, Release)
 
+already_AddRefed<DOMPointReadOnly>
+DOMPointReadOnly::FromPoint(const GlobalObject& aGlobal, const DOMPointInit& aParams)
+{
+  RefPtr<DOMPointReadOnly> obj =
+    new DOMPointReadOnly(aGlobal.GetAsSupports(), aParams.mX, aParams.mY,
+                         aParams.mZ, aParams.mW);
+  return obj.forget();
+}
+
+already_AddRefed<DOMPointReadOnly>
+DOMPointReadOnly::Constructor(const GlobalObject& aGlobal, double aX, double aY,
+                              double aZ, double aW, ErrorResult& aRV)
+{
+  RefPtr<DOMPointReadOnly> obj =
+    new DOMPointReadOnly(aGlobal.GetAsSupports(), aX, aY, aZ, aW);
+  return obj.forget();
+}
+
+JSObject*
+DOMPointReadOnly::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return DOMPointReadOnlyBinding::Wrap(aCx, this, aGivenProto);
+}
+
 already_AddRefed<DOMPoint>
-DOMPoint::Constructor(const GlobalObject& aGlobal, const DOMPointInit& aParams,
-                      ErrorResult& aRV)
+DOMPoint::FromPoint(const GlobalObject& aGlobal, const DOMPointInit& aParams)
 {
   RefPtr<DOMPoint> obj =
     new DOMPoint(aGlobal.GetAsSupports(), aParams.mX, aParams.mY,
diff --git a/dom/base/DOMPoint.h b/dom/base/DOMPoint.h
index 1a85982cc7..79937f83a3 100644
--- a/dom/base/DOMPoint.h
+++ b/dom/base/DOMPoint.h
@@ -33,6 +33,12 @@ public:
   {
   }
 
+  static already_AddRefed<DOMPointReadOnly>
+  FromPoint(const GlobalObject& aGlobal, const DOMPointInit& aParams);
+  static already_AddRefed<DOMPointReadOnly>
+  Constructor(const GlobalObject& aGlobal, double aX, double aY,
+              double aZ, double aW, ErrorResult& aRV);
+
   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(DOMPointReadOnly)
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(DOMPointReadOnly)
 
@@ -41,6 +47,9 @@ public:
   double Z() const { return mZ; }
   double W() const { return mW; }
 
+  nsISupports* GetParentObject() const { return mParent; }
+  virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
 protected:
   virtual ~DOMPointReadOnly() {}
 
@@ -57,13 +66,11 @@ public:
   {}
 
   static already_AddRefed<DOMPoint>
-  Constructor(const GlobalObject& aGlobal, const DOMPointInit& aParams,
-              ErrorResult& aRV);
+  FromPoint(const GlobalObject& aGlobal, const DOMPointInit& aParams);
   static already_AddRefed<DOMPoint>
   Constructor(const GlobalObject& aGlobal, double aX, double aY,
               double aZ, double aW, ErrorResult& aRV);
 
-  nsISupports* GetParentObject() const { return mParent; }
   virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
 
   void SetX(double aX) { mX = aX; }
diff --git a/dom/base/DOMQuad.cpp b/dom/base/DOMQuad.cpp
index 9da70c043d..2cf55e1b8b 100644
--- a/dom/base/DOMQuad.cpp
+++ b/dom/base/DOMQuad.cpp
@@ -14,7 +14,7 @@ using namespace mozilla;
 using namespace mozilla::dom;
 using namespace mozilla::gfx;
 
-NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DOMQuad, mParent, mBounds, mPoints[0],
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DOMQuad, mParent, mPoints[0],
                                       mPoints[1], mPoints[2], mPoints[3])
 
 NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(DOMQuad, AddRef)
@@ -52,10 +52,10 @@ DOMQuad::Constructor(const GlobalObject& aGlobal,
                      ErrorResult& aRV)
 {
   RefPtr<DOMQuad> obj = new DOMQuad(aGlobal.GetAsSupports());
-  obj->mPoints[0] = DOMPoint::Constructor(aGlobal, aP1, aRV);
-  obj->mPoints[1] = DOMPoint::Constructor(aGlobal, aP2, aRV);
-  obj->mPoints[2] = DOMPoint::Constructor(aGlobal, aP3, aRV);
-  obj->mPoints[3] = DOMPoint::Constructor(aGlobal, aP4, aRV);
+  obj->mPoints[0] = DOMPoint::FromPoint(aGlobal, aP1);
+  obj->mPoints[1] = DOMPoint::FromPoint(aGlobal, aP2);
+  obj->mPoints[2] = DOMPoint::FromPoint(aGlobal, aP3);
+  obj->mPoints[3] = DOMPoint::FromPoint(aGlobal, aP4);
   return obj.forget();
 }
 
@@ -73,87 +73,44 @@ DOMQuad::Constructor(const GlobalObject& aGlobal, const DOMRectReadOnly& aRect,
   return obj.forget();
 }
 
-class DOMQuad::QuadBounds final : public DOMRectReadOnly
+void
+DOMQuad::GetHorizontalMinMax(double* aX1, double* aX2) const
 {
-public:
-  explicit QuadBounds(DOMQuad* aQuad)
-    : DOMRectReadOnly(aQuad->GetParentObject())
-    , mQuad(aQuad)
-  {}
-
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(QuadBounds, DOMRectReadOnly)
-  NS_DECL_ISUPPORTS_INHERITED
-
-  virtual double X() const override
-  {
-    double x1, x2;
-    GetHorizontalMinMax(&x1, &x2);
-    return x1;
-  }
-  virtual double Y() const override
-  {
-    double y1, y2;
-    GetVerticalMinMax(&y1, &y2);
-    return y1;
-  }
-  virtual double Width() const override
-  {
-    double x1, x2;
-    GetHorizontalMinMax(&x1, &x2);
-    return x2 - x1;
-  }
-  virtual double Height() const override
-  {
-    double y1, y2;
-    GetVerticalMinMax(&y1, &y2);
-    return y2 - y1;
-  }
-
-  void GetHorizontalMinMax(double* aX1, double* aX2) const
-  {
-    double x1, x2;
-    x1 = x2 = mQuad->Point(0)->X();
-    for (uint32_t i = 1; i < 4; ++i) {
-      double x = mQuad->Point(i)->X();
-      x1 = std::min(x1, x);
-      x2 = std::max(x2, x);
-    }
-    *aX1 = x1;
-    *aX2 = x2;
+  double x1, x2;
+  x1 = x2 = Point(0)->X();
+  for (uint32_t i = 1; i < 4; ++i) {
+    double x = Point(i)->X();
+    x1 = std::min(x1, x);
+    x2 = std::max(x2, x);
   }
+  *aX1 = x1;
+  *aX2 = x2;
+}
 
-  void GetVerticalMinMax(double* aY1, double* aY2) const
-  {
-    double y1, y2;
-    y1 = y2 = mQuad->Point(0)->Y();
-    for (uint32_t i = 1; i < 4; ++i) {
-      double y = mQuad->Point(i)->Y();
-      y1 = std::min(y1, y);
-      y2 = std::max(y2, y);
-    }
-    *aY1 = y1;
-    *aY2 = y2;
+void
+DOMQuad::GetVerticalMinMax(double* aY1, double* aY2) const
+{
+  double y1, y2;
+  y1 = y2 = Point(0)->Y();
+  for (uint32_t i = 1; i < 4; ++i) {
+    double y = Point(i)->Y();
+    y1 = std::min(y1, y);
+    y2 = std::max(y2, y);
   }
+  *aY1 = y1;
+  *aY2 = y2;
+}
 
-protected:
-  virtual ~QuadBounds() {}
-
-  RefPtr<DOMQuad> mQuad;
-};
-
-NS_IMPL_CYCLE_COLLECTION_INHERITED(DOMQuad::QuadBounds, DOMRectReadOnly, mQuad)
-
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(DOMQuad::QuadBounds)
-NS_INTERFACE_MAP_END_INHERITING(DOMRectReadOnly)
+already_AddRefed<DOMRectReadOnly>
+DOMQuad::GetBounds() const
+{
+  double x1, x2;
+  double y1, y2;
 
-NS_IMPL_ADDREF_INHERITED(DOMQuad::QuadBounds, DOMRectReadOnly)
-NS_IMPL_RELEASE_INHERITED(DOMQuad::QuadBounds, DOMRectReadOnly)
+  GetHorizontalMinMax(&x1, &x2);
+  GetVerticalMinMax(&y1, &y2);
 
-DOMRectReadOnly*
-DOMQuad::Bounds() const
-{
-  if (!mBounds) {
-    mBounds = new QuadBounds(const_cast<DOMQuad*>(this));
-  }
-  return mBounds;
+  RefPtr<DOMRectReadOnly> rval = new DOMRectReadOnly(GetParentObject(),
+                                                     x1, y1, x2 - x1, y2 - y1);
+  return rval.forget();
 }
diff --git a/dom/base/DOMQuad.h b/dom/base/DOMQuad.h
index 89d258a106..25cf7dbd06 100644
--- a/dom/base/DOMQuad.h
+++ b/dom/base/DOMQuad.h
@@ -47,20 +47,20 @@ public:
   Constructor(const GlobalObject& aGlobal, const DOMRectReadOnly& aRect,
               ErrorResult& aRV);
 
-  DOMRectReadOnly* Bounds() const;
+  already_AddRefed<DOMRectReadOnly> GetBounds() const;
   DOMPoint* P1() const { return mPoints[0]; }
   DOMPoint* P2() const { return mPoints[1]; }
   DOMPoint* P3() const { return mPoints[2]; }
   DOMPoint* P4() const { return mPoints[3]; }
 
-  DOMPoint* Point(uint32_t aIndex) { return mPoints[aIndex]; }
+  DOMPoint* Point(uint32_t aIndex) const { return mPoints[aIndex]; }
 
 protected:
-  class QuadBounds;
+  void GetHorizontalMinMax(double* aX1, double* aX2) const;
+  void GetVerticalMinMax(double* aY1, double* aY2) const;
 
   nsCOMPtr<nsISupports> mParent;
   RefPtr<DOMPoint> mPoints[4];
-  mutable RefPtr<QuadBounds> mBounds; // allocated lazily
 };
 
 } // namespace dom
diff --git a/dom/base/DOMRect.cpp b/dom/base/DOMRect.cpp
index 3728ea7a7c..ecd56f10a7 100644
--- a/dom/base/DOMRect.cpp
+++ b/dom/base/DOMRect.cpp
@@ -27,6 +27,15 @@ DOMRectReadOnly::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
   return DOMRectReadOnlyBinding::Wrap(aCx, this, aGivenProto);
 }
 
+already_AddRefed<DOMRectReadOnly>
+DOMRectReadOnly::Constructor(const GlobalObject& aGlobal, double aX, double aY,
+                             double aWidth, double aHeight, ErrorResult& aRv)
+{
+  RefPtr<DOMRectReadOnly> obj =
+    new DOMRectReadOnly(aGlobal.GetAsSupports(), aX, aY, aWidth, aHeight);
+  return obj.forget();
+}
+
 // -----------------------------------------------------------------------------
 
 NS_IMPL_ISUPPORTS_INHERITED(DOMRect, DOMRectReadOnly, nsIDOMClientRect)
@@ -54,16 +63,8 @@ DOMRect::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
 }
 
 already_AddRefed<DOMRect>
-DOMRect::Constructor(const GlobalObject& aGlobal, ErrorResult& aRV)
-{
-  RefPtr<DOMRect> obj =
-    new DOMRect(aGlobal.GetAsSupports(), 0.0, 0.0, 0.0, 0.0);
-  return obj.forget();
-}
-
-already_AddRefed<DOMRect>
 DOMRect::Constructor(const GlobalObject& aGlobal, double aX, double aY,
-                     double aWidth, double aHeight, ErrorResult& aRV)
+                     double aWidth, double aHeight, ErrorResult& aRv)
 {
   RefPtr<DOMRect> obj =
     new DOMRect(aGlobal.GetAsSupports(), aX, aY, aWidth, aHeight);
diff --git a/dom/base/DOMRect.h b/dom/base/DOMRect.h
index da3162be0c..baf3268b20 100644
--- a/dom/base/DOMRect.h
+++ b/dom/base/DOMRect.h
@@ -32,8 +32,13 @@ public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DOMRectReadOnly)
 
-  explicit DOMRectReadOnly(nsISupports* aParent)
+  explicit DOMRectReadOnly(nsISupports* aParent, double aX = 0, double aY = 0,
+                           double aWidth = 0, double aHeight = 0)
     : mParent(aParent)
+    , mX(aX)
+    , mY(aY)
+    , mWidth(aWidth)
+    , mHeight(aHeight)
   {
   }
 
@@ -44,10 +49,26 @@ public:
   }
   virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
 
-  virtual double X() const = 0;
-  virtual double Y() const = 0;
-  virtual double Width() const = 0;
-  virtual double Height() const = 0;
+  static already_AddRefed<DOMRectReadOnly>
+  Constructor(const GlobalObject& aGlobal, double aX, double aY,
+              double aWidth, double aHeight, ErrorResult& aRv);
+
+  double X() const
+  {
+    return mX;
+  }
+  double Y() const
+  {
+    return mY;
+  }
+  double Width() const
+  {
+    return mWidth;
+  }
+  double Height() const
+  {
+    return mHeight;
+  }
 
   double Left() const
   {
@@ -72,6 +93,7 @@ public:
 
 protected:
   nsCOMPtr<nsISupports> mParent;
+  double mX, mY, mWidth, mHeight;
 };
 
 class DOMRect final : public DOMRectReadOnly
@@ -80,22 +102,16 @@ class DOMRect final : public DOMRectReadOnly
 public:
   explicit DOMRect(nsISupports* aParent, double aX = 0, double aY = 0,
                    double aWidth = 0, double aHeight = 0)
-    : DOMRectReadOnly(aParent)
-    , mX(aX)
-    , mY(aY)
-    , mWidth(aWidth)
-    , mHeight(aHeight)
+    : DOMRectReadOnly(aParent, aX, aY, aWidth, aHeight)
   {
   }
-  
+
   NS_DECL_ISUPPORTS_INHERITED
   NS_DECL_NSIDOMCLIENTRECT
 
   static already_AddRefed<DOMRect>
-  Constructor(const GlobalObject& aGlobal, ErrorResult& aRV);
-  static already_AddRefed<DOMRect>
   Constructor(const GlobalObject& aGlobal, double aX, double aY,
-              double aWidth, double aHeight, ErrorResult& aRV);
+              double aWidth, double aHeight, ErrorResult& aRv);
 
   virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
 
@@ -104,23 +120,6 @@ public:
   }
   void SetLayoutRect(const nsRect& aLayoutRect);
 
-  virtual double X() const override
-  {
-    return mX;
-  }
-  virtual double Y() const override
-  {
-    return mY;
-  }
-  virtual double Width() const override
-  {
-    return mWidth;
-  }
-  virtual double Height() const override
-  {
-    return mHeight;
-  }
-
   void SetX(double aX)
   {
     mX = aX;
@@ -138,11 +137,8 @@ public:
     mHeight = aHeight;
   }
 
-protected:
-  double mX, mY, mWidth, mHeight;
-
 private:
-  ~DOMRect() {};
+  ~DOMRect() {}
 };
 
 class DOMRectList final : public nsIDOMClientRectList,