--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -830,16 +830,23 @@ nsLayoutUtils::FindContentFor(ViewID aId
 
   if (exists) {
     return content;
   } else {
     return nullptr;
   }
 }
 
+ViewID
+nsLayoutUtils::ViewIDForASR(const mozilla::ActiveScrolledRoot* aASR)
+{
+  nsIContent* content = aASR->mScrollableFrame->GetScrolledFrame()->GetContent();
+  return nsLayoutUtils::FindOrCreateIDFor(content);
+}
+
 nsIFrame*
 GetScrollFrameFromContent(nsIContent* aContent)
 {
   nsIFrame* frame = aContent->GetPrimaryFrame();
   if (aContent->OwnerDoc()->GetRootElement() == aContent) {
     nsIPresShell* presShell = frame ? frame->PresContext()->PresShell() : nullptr;
     if (!presShell) {
       presShell = aContent->OwnerDoc()->GetShell();

--- a/layout/base/nsLayoutUtils.h
+++ b/layout/base/nsLayoutUtils.h
@@ -67,16 +67,17 @@ namespace mozilla {
 enum class CSSPseudoElementType : uint8_t;
 class EventListenerManager;
 enum class LayoutFrameType : uint8_t;
 struct IntrinsicSize;
 struct ContainerLayerParameters;
 class WritingMode;
 class DisplayItemClip;
 class EffectSet;
+struct ActiveScrolledRoot;
 namespace dom {
 class CanvasRenderingContext2D;
 class DOMRectList;
 class Element;
 class HTMLImageElement;
 class HTMLCanvasElement;
 class HTMLVideoElement;
 class OffscreenCanvas;
@@ -179,16 +180,22 @@ public:
   static ViewID FindOrCreateIDFor(nsIContent* aContent);
 
   /**
    * Find content for given ID.
    */
   static nsIContent* FindContentFor(ViewID aId);
 
   /**
+   * Find the view ID (or generate a new one) for the content element
+   * corresponding to the ASR.
+   */
+  static ViewID ViewIDForASR(const mozilla::ActiveScrolledRoot* aASR);
+
+  /**
    * Find the scrollable frame for a given ID.
    */
   static nsIScrollableFrame* FindScrollableFrameFor(ViewID aId);
 
   /**
    * Find the ID for a given scrollable frame.
    */
   static ViewID FindIDForScrollableFrame(nsIScrollableFrame* aScrollable);

--- a/layout/painting/FrameLayerBuilder.cpp
+++ b/layout/painting/FrameLayerBuilder.cpp
@@ -4981,23 +4981,16 @@ FindDirectChildASR(const ActiveScrolledR
   const ActiveScrolledRoot* directChild = aDescendant;
   while (directChild->mParent != aParent) {
     directChild = directChild->mParent;
     MOZ_RELEASE_ASSERT(directChild, "this must not be null");
   }
   return directChild;
 }
 
-static FrameMetrics::ViewID
-ViewIDForASR(const ActiveScrolledRoot* aASR)
-{
-  nsIContent* content = aASR->mScrollableFrame->GetScrolledFrame()->GetContent();
-  return nsLayoutUtils::FindOrCreateIDFor(content);
-}
-
 static void
 FixUpFixedPositionLayer(Layer* aLayer,
                         const ActiveScrolledRoot* aTargetASR,
                         const ActiveScrolledRoot* aLeafScrollMetadataASR,
                         const ActiveScrolledRoot* aContainerScrollMetadataASR,
                         const ActiveScrolledRoot* aContainerCompositorASR,
                         bool aIsFixedToRootScrollFrame)
 {
@@ -5036,17 +5029,17 @@ FixUpFixedPositionLayer(Layer* aLayer,
     aLeafScrollMetadataASR == aContainerScrollMetadataASR
       ? aContainerCompositorASR
       : aLeafScrollMetadataASR;
 
   // The goal of the annotation is to have the layer move with aTargetASR.
   if (compositorASR && aTargetASR != compositorASR) {
     // Mark this layer as fixed with respect to the child scroll frame of aTargetASR.
     aLayer->SetFixedPositionData(
-      ViewIDForASR(FindDirectChildASR(aTargetASR, compositorASR)),
+      nsLayoutUtils::ViewIDForASR(FindDirectChildASR(aTargetASR, compositorASR)),
       aLayer->GetFixedPositionAnchor(),
       aLayer->GetFixedPositionSides());
   } else {
     // Remove the fixed annotation from the layer, unless this layers is fixed
     // to the document's root scroll frame - in that case, the annotation is
     // needed for hit testing, because fixed layers in iframes should scroll
     // the iframe, even though their position is not affected by scrolling in
     // the iframe. (The APZ hit testing code has a special case for this.)