Bug 1729236 - Remove GetPaintRect. r=jrmuizel

Differential Revision: https://phabricator.services.mozilla.com/D124590

layout/painting/nsDisplayList.h

@@ -2936,10 +2936,8 @@ class nsDisplayItem : public nsDisplayItemLink {
   virtual Maybe<nsRect> GetClipWithRespectToASR(
       nsDisplayListBuilder* aBuilder, const ActiveScrolledRoot* aASR) const;
 
-  const nsRect& GetPaintRect() const { return mBuildingRect; }
-
   virtual const nsRect& GetUntransformedPaintRect() const {
-    return GetPaintRect();
+    return GetBuildingRect();
   }
 
   nsRect GetPaintRect(nsDisplayListBuilder* aBuilder, gfxContext* aCtx);
@@ -6465,11 +6463,6 @@ class nsDisplayTransform : public nsPaintedDisplayItem {
     return UntransformRect(aBuilder, GetBuildingRect(), aOutRect);
   }
 
-  bool UntransformPaintRect(nsDisplayListBuilder* aBuilder,
-                            nsRect* aOutRect) const {
-    return UntransformRect(aBuilder, GetPaintRect(), aOutRect);
-  }
-
   static gfx::Point3D GetDeltaToTransformOrigin(const nsIFrame* aFrame,
                                                 TransformReferenceBox&,
                                                 float aAppUnitsPerPixel);