--- a/gfx/layers/LayerMetricsWrapper.h
+++ b/gfx/layers/LayerMetricsWrapper.h
@@ -173,23 +173,17 @@ public:
   {
     return IsValid();
   }
 
   bool IsScrollInfoLayer() const
   {
     MOZ_ASSERT(IsValid());
 
-    // If we are not at the bottommost layer then it's
-    // a stack of container layers all the way down to
-    // mLayer, which we can ignore. We only care about
-    // non-container descendants.
-    return Metrics().IsScrollable()
-        && mLayer->AsContainerLayer()
-        && !mLayer->GetFirstChild();
+    return Metrics().IsScrollInfoLayer();
   }
 
   LayerMetricsWrapper GetParent() const
   {
     MOZ_ASSERT(IsValid());
 
     if (!AtTopLayer()) {
       return LayerMetricsWrapper(mLayer, mIndex + 1);

--- a/gfx/layers/wr/WebRenderScrollData.cpp
+++ b/gfx/layers/wr/WebRenderScrollData.cpp
@@ -32,17 +32,16 @@ WebRenderLayerScrollData::Initialize(Web
   MOZ_ASSERT(mDescendantCount == -1); // Don't allow re-setting an already set value
   mDescendantCount = aDescendantCount;
 
   MOZ_ASSERT(aLayer);
   for (uint32_t i = 0; i < aLayer->GetScrollMetadataCount(); i++) {
     mScrollIds.AppendElement(aOwner.AddMetadata(aLayer->GetScrollMetadata(i)));
   }
 
-  mIsScrollInfoLayer = aLayer->AsContainerLayer() && !aLayer->GetFirstChild();
   mTransform = aLayer->GetTransform();
   mTransformIsPerspective = aLayer->GetTransformIsPerspective();
   mEventRegions = aLayer->GetEventRegions();
   mVisibleRegion = aLayer->GetVisibleRegion();
   mReferentId = aLayer->AsRefLayer()
       ? Some(aLayer->AsRefLayer()->GetReferentId())
       : Nothing();
   mEventRegionsOverride = aLayer->AsContainerLayer()

--- a/gfx/layers/wr/WebRenderScrollData.h
+++ b/gfx/layers/wr/WebRenderScrollData.h
@@ -47,17 +47,16 @@ public:
 
   // Return the ScrollMetadata object that used to be on the original Layer
   // at the given index. Since we deduplicate the ScrollMetadata objects into
   // the array in the owning WebRenderScrollData object, we need to be passed
   // in a reference to that owner as well.
   const ScrollMetadata& GetScrollMetadata(const WebRenderScrollData& aOwner,
                                           size_t aIndex) const;
 
-  bool IsScrollInfoLayer() const { return mIsScrollInfoLayer; }
   gfx::Matrix4x4 GetTransform() const { return mTransform; }
   CSSTransformMatrix GetTransformTyped() const;
   bool GetTransformIsPerspective() const { return mTransformIsPerspective; }
   EventRegions GetEventRegions() const { return mEventRegions; }
   const LayerIntRegion& GetVisibleRegion() const { return mVisibleRegion; }
   Maybe<uint64_t> GetReferentId() const { return mReferentId; }
   EventRegionsOverride GetEventRegionsOverride() const { return mEventRegionsOverride; }
   const ScrollThumbData& GetScrollThumbData() const { return mScrollThumbData; }
@@ -79,17 +78,16 @@ private:
   // mScrollMetadatas array. This indirection is used to deduplicate the
   // ScrollMetadata objects, since there is usually heavy duplication of them
   // within a layer tree.
   nsTArray<size_t> mScrollIds;
 
   // Various data that we collect from the Layer in Initialize(), serialize
   // over IPC, and use on the parent side in APZ.
 
-  bool mIsScrollInfoLayer;
   gfx::Matrix4x4 mTransform;
   bool mTransformIsPerspective;
   EventRegions mEventRegions;
   LayerIntRegion mVisibleRegion;
   Maybe<uint64_t> mReferentId;
   EventRegionsOverride mEventRegionsOverride;
   ScrollThumbData mScrollThumbData;
   uint64_t mScrollbarAnimationId;
@@ -183,17 +181,16 @@ struct ParamTraits<mozilla::layers::WebR
 {
   typedef mozilla::layers::WebRenderLayerScrollData paramType;
 
   static void
   Write(Message* aMsg, const paramType& aParam)
   {
     WriteParam(aMsg, aParam.mDescendantCount);
     WriteParam(aMsg, aParam.mScrollIds);
-    WriteParam(aMsg, aParam.mIsScrollInfoLayer);
     WriteParam(aMsg, aParam.mTransform);
     WriteParam(aMsg, aParam.mTransformIsPerspective);
     WriteParam(aMsg, aParam.mEventRegions);
     WriteParam(aMsg, aParam.mVisibleRegion);
     WriteParam(aMsg, aParam.mReferentId);
     WriteParam(aMsg, aParam.mEventRegionsOverride);
     WriteParam(aMsg, aParam.mScrollThumbData);
     WriteParam(aMsg, aParam.mScrollbarAnimationId);
@@ -202,17 +199,16 @@ struct ParamTraits<mozilla::layers::WebR
     WriteParam(aMsg, aParam.mFixedPosScrollContainerId);
   }
 
   static bool
   Read(const Message* aMsg, PickleIterator* aIter, paramType* aResult)
   {
     return ReadParam(aMsg, aIter, &aResult->mDescendantCount)
         && ReadParam(aMsg, aIter, &aResult->mScrollIds)
-        && ReadParam(aMsg, aIter, &aResult->mIsScrollInfoLayer)
         && ReadParam(aMsg, aIter, &aResult->mTransform)
         && ReadParam(aMsg, aIter, &aResult->mTransformIsPerspective)
         && ReadParam(aMsg, aIter, &aResult->mEventRegions)
         && ReadParam(aMsg, aIter, &aResult->mVisibleRegion)
         && ReadParam(aMsg, aIter, &aResult->mReferentId)
         && ReadParam(aMsg, aIter, &aResult->mEventRegionsOverride)
         && ReadParam(aMsg, aIter, &aResult->mScrollThumbData)
         && ReadParam(aMsg, aIter, &aResult->mScrollbarAnimationId)

--- a/gfx/layers/wr/WebRenderScrollDataWrapper.h
+++ b/gfx/layers/wr/WebRenderScrollDataWrapper.h
@@ -124,18 +124,17 @@ public:
   {
     return IsValid();
   }
 
   bool IsScrollInfoLayer() const
   {
     MOZ_ASSERT(IsValid());
 
-    return Metrics().IsScrollable()
-        && mLayer->IsScrollInfoLayer();
+    return Metrics().IsScrollInfoLayer();
   }
 
   WebRenderScrollDataWrapper GetLastChild() const
   {
     MOZ_ASSERT(IsValid());
 
     if (!AtBottomLayer()) {
       // If we're still walking around in the virtual container layers created