--- a/gfx/layers/wr/WebRenderScrollData.h
+++ b/gfx/layers/wr/WebRenderScrollData.h
@@ -69,16 +69,17 @@ public:
   const LayerIntRegion& GetVisibleRegion() const { return mVisibleRegion; }
   void SetReferentId(uint64_t aReferentId) { mReferentId = Some(aReferentId); }
   Maybe<uint64_t> GetReferentId() const { return mReferentId; }
   EventRegionsOverride GetEventRegionsOverride() const { return mEventRegionsOverride; }
   const ScrollThumbData& GetScrollThumbData() const { return mScrollThumbData; }
   const uint64_t& GetScrollbarAnimationId() const { return mScrollbarAnimationId; }
   FrameMetrics::ViewID GetScrollbarTargetContainerId() const { return mScrollbarTargetContainerId; }
   bool IsScrollbarContainer() const { return mIsScrollbarContainer; }
+  void SetFixedPositionScrollContainerId(FrameMetrics::ViewID aId) { mFixedPosScrollContainerId = aId; }
   FrameMetrics::ViewID GetFixedPositionScrollContainerId() const { return mFixedPosScrollContainerId; }
 
   void Dump(const WebRenderScrollData& aOwner) const;
 
   friend struct IPC::ParamTraits<WebRenderLayerScrollData>;
 
 private:
   // The number of descendants this layer has (not including the layer itself).

--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -2082,23 +2082,30 @@ nsLayoutUtils::SetFixedPositionLayerData
       } else {
         anchor.y = anchorRect.YMost();
       }
     } else if (position->mOffset.GetTopUnit() != eStyleUnit_Auto) {
       sides |= eSideBitsTop;
     }
   }
 
+  ViewID id = ScrollIdForRootScrollFrame(aPresContext);
+  aLayer->SetFixedPositionData(id, anchor, sides);
+}
+
+FrameMetrics::ViewID
+nsLayoutUtils::ScrollIdForRootScrollFrame(nsPresContext* aPresContext)
+{
   ViewID id = FrameMetrics::NULL_SCROLL_ID;
   if (nsIFrame* rootScrollFrame = aPresContext->PresShell()->GetRootScrollFrame()) {
     if (nsIContent* content = rootScrollFrame->GetContent()) {
       id = FindOrCreateIDFor(content);
     }
   }
-  aLayer->SetFixedPositionData(id, anchor, sides);
+  return id;
 }
 
 bool
 nsLayoutUtils::ViewportHasDisplayPort(nsPresContext* aPresContext)
 {
   nsIFrame* rootScrollFrame =
     aPresContext->PresShell()->GetRootScrollFrame();
   return rootScrollFrame &&

--- a/layout/base/nsLayoutUtils.h
+++ b/layout/base/nsLayoutUtils.h
@@ -568,16 +568,22 @@ public:
    */
   static void SetFixedPositionLayerData(Layer* aLayer, const nsIFrame* aViewportFrame,
                                         const nsRect& aAnchorRect,
                                         const nsIFrame* aFixedPosFrame,
                                         nsPresContext* aPresContext,
                                         const ContainerLayerParameters& aContainerParameters);
 
   /**
+   * Get the scroll id for the root scrollframe of the presshell of the given
+   * prescontext. Returns NULL_SCROLL_ID if it couldn't be found.
+   */
+  static FrameMetrics::ViewID ScrollIdForRootScrollFrame(nsPresContext* aPresContext);
+
+  /**
    * Return true if aPresContext's viewport has a displayport.
    */
   static bool ViewportHasDisplayPort(nsPresContext* aPresContext);
 
   /**
    * Return true if aFrame is a fixed-pos frame and is a child of a viewport
    * which has a displayport. These frames get special treatment from the compositor.
    * aDisplayPort, if non-null, is set to the display port rectangle (relative to

--- a/layout/painting/nsDisplayList.cpp
+++ b/layout/painting/nsDisplayList.cpp
@@ -6683,16 +6683,28 @@ bool nsDisplayFixedPosition::TryMerge(ns
   if (other->mFrame != mFrame)
     return false;
   if (aItem->GetClipChain() != GetClipChain())
     return false;
   MergeFromTrackingMergedFrames(other);
   return true;
 }
 
+bool
+nsDisplayFixedPosition::UpdateScrollData(mozilla::layers::WebRenderScrollData* aData,
+                                         mozilla::layers::WebRenderLayerScrollData* aLayerData)
+{
+  if (aLayerData) {
+    FrameMetrics::ViewID id = nsLayoutUtils::ScrollIdForRootScrollFrame(
+        Frame()->PresContext());
+    aLayerData->SetFixedPositionScrollContainerId(id);
+  }
+  return true;
+}
+
 TableType
 GetTableTypeFromFrame(nsIFrame* aFrame)
 {
   if (aFrame->IsTableFrame()) {
     return TableType::TABLE;
   }
 
   if (aFrame->IsTableColFrame()) {

--- a/layout/painting/nsDisplayList.h
+++ b/layout/painting/nsDisplayList.h
@@ -4292,16 +4292,19 @@ public:
   virtual bool ShouldFixToViewport(nsDisplayListBuilder* aBuilder) override { return mIsFixedBackground; }
 
   virtual uint32_t GetPerFrameKey() override { return (mIndex << nsDisplayItem::TYPE_BITS) | nsDisplayItem::GetPerFrameKey(); }
 
   AnimatedGeometryRoot* AnimatedGeometryRootForScrollMetadata() const override {
     return mAnimatedGeometryRootForScrollMetadata;
   }
 
+  virtual bool UpdateScrollData(mozilla::layers::WebRenderScrollData* aData,
+                                mozilla::layers::WebRenderLayerScrollData* aLayerData) override;
+
 protected:
   // For background-attachment:fixed
   nsDisplayFixedPosition(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
                          nsDisplayList* aList, uint32_t aIndex);
   void Init(nsDisplayListBuilder* aBuilder);
 
   AnimatedGeometryRoot* mAnimatedGeometryRootForScrollMetadata;
   uint32_t mIndex;