diff --git a/dom/base/DOMQuad.cpp b/dom/base/DOMQuad.cpp
index 2cf55e1b8b..a64c883982 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, mPoints[0],
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DOMQuad, mParent, mBounds, mPoints[0],
                                       mPoints[1], mPoints[2], mPoints[3])
 
 NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(DOMQuad, AddRef)
@@ -101,6 +101,15 @@ DOMQuad::GetVerticalMinMax(double* aY1, double* aY2) const
   *aY2 = y2;
 }
 
+DOMRectReadOnly*
+DOMQuad::Bounds()
+{
+  if (!mBounds) {
+    mBounds = GetBounds();
+  }
+  return mBounds;
+}
+
 already_AddRefed<DOMRectReadOnly>
 DOMQuad::GetBounds() const
 {
@@ -114,3 +123,12 @@ DOMQuad::GetBounds() const
                                                      x1, y1, x2 - x1, y2 - y1);
   return rval.forget();
 }
+
+void
+DOMQuad::ToJSON(DOMQuadJSON& aInit)
+{
+  aInit.mP1.Construct(RefPtr<DOMPoint>(P1()).forget());
+  aInit.mP2.Construct(RefPtr<DOMPoint>(P2()).forget());
+  aInit.mP3.Construct(RefPtr<DOMPoint>(P3()).forget());
+  aInit.mP4.Construct(RefPtr<DOMPoint>(P4()).forget());
+}
diff --git a/dom/base/DOMQuad.h b/dom/base/DOMQuad.h
index 25cf7dbd06..db38e5d236 100644
--- a/dom/base/DOMQuad.h
+++ b/dom/base/DOMQuad.h
@@ -20,6 +20,7 @@ namespace dom {
 
 class DOMRectReadOnly;
 class DOMPoint;
+struct DOMQuadJSON;
 struct DOMPointInit;
 
 class DOMQuad final : public nsWrapperCache
@@ -47,6 +48,7 @@ public:
   Constructor(const GlobalObject& aGlobal, const DOMRectReadOnly& aRect,
               ErrorResult& aRV);
 
+  DOMRectReadOnly* Bounds();
   already_AddRefed<DOMRectReadOnly> GetBounds() const;
   DOMPoint* P1() const { return mPoints[0]; }
   DOMPoint* P2() const { return mPoints[1]; }
@@ -55,12 +57,15 @@ public:
 
   DOMPoint* Point(uint32_t aIndex) const { return mPoints[aIndex]; }
 
+  void ToJSON(DOMQuadJSON& aInit);
+
 protected:
   void GetHorizontalMinMax(double* aX1, double* aX2) const;
   void GetVerticalMinMax(double* aY1, double* aY2) const;
 
   nsCOMPtr<nsISupports> mParent;
   RefPtr<DOMPoint> mPoints[4];
+  RefPtr<DOMRectReadOnly> mBounds;
 };
 
 } // namespace dom
diff --git a/dom/base/nsDeprecatedOperationList.h b/dom/base/nsDeprecatedOperationList.h
index 0bae2d6211..bb9d8fd3b1 100644
--- a/dom/base/nsDeprecatedOperationList.h
+++ b/dom/base/nsDeprecatedOperationList.h
@@ -47,3 +47,4 @@ DEPRECATED_OPERATION(PrefixedFullscreenAPI)
 DEPRECATED_OPERATION(LenientSetter)
 DEPRECATED_OPERATION(FileLastModifiedDate)
 DEPRECATED_OPERATION(ImageBitmapRenderingContext_TransferImageBitmap)
+DEPRECATED_OPERATION(DOMQuadBoundsAttr)
diff --git a/dom/locales/en-US/chrome/dom/dom.properties b/dom/locales/en-US/chrome/dom/dom.properties
index 60104a63ad..27b4eebf12 100644
--- a/dom/locales/en-US/chrome/dom/dom.properties
+++ b/dom/locales/en-US/chrome/dom/dom.properties
@@ -320,3 +320,4 @@ LargeAllocationNonE10S=A Large-Allocation header was ignored due to the document
 PushStateFloodingPrevented=Call to pushState or replaceState ignored due to excessive calls within a short timeframe.
 # LOCALIZATION NOTE: Do not translate "Reload"
 ReloadFloodingPrevented=Call to Reload ignored due to excessive calls within a short timeframe.
+DOMQuadBoundsAttrWarning=DOMQuad.bounds is deprecated in favor of DOMQuad.getBounds()
diff --git a/dom/webidl/DOMQuad.webidl b/dom/webidl/DOMQuad.webidl
index f3674e9ad7..7370330b29 100644
--- a/dom/webidl/DOMQuad.webidl
+++ b/dom/webidl/DOMQuad.webidl
@@ -21,5 +21,21 @@ interface DOMQuad {
     [SameObject] readonly attribute DOMPoint p4;
     [NewObject] DOMRectReadOnly getBounds();
 
-    [Default] object toJSON();
+    [SameObject, Deprecated=DOMQuadBoundsAttr] readonly attribute DOMRectReadOnly bounds;
+
+    DOMQuadJSON toJSON();
+};
+
+dictionary DOMQuadJSON {
+    DOMPoint p1;
+    DOMPoint p2;
+    DOMPoint p3;
+    DOMPoint p4;
+};
+
+dictionary DOMQuadInit {
+    DOMPointInit p1;
+    DOMPointInit p2;
+    DOMPointInit p3;
+    DOMPointInit p4;
 };